2:21 Yes, it does happen now days. I operate a large nationwide e-waste facility and I am proud to have rescued 100's of retro pieces from destruction while simultaneously building my own collection. My most recent save was just this week where I pulled a Commodore Plus4 still in the box from the pile.
I worked in one of those places for exactly one day. Everything ripped apart, stripped, separated, crushed, binned. No exceptions. They had contracts with governmental datacenters so they had flat zero tolerance policy which absolutely prohibited any kind of salvage because of data privacy concerns.
@@pwnmeisterage Very true. There will always be clients who demand total destruction with no exceptions typically involving more modern technology. Whereas the vintage stuff tends to come from estate cleanouts and recycling drives where re-use is rarely an issue and in some situations, encouraged.
@@boardsort It is true. But also sad that the privacy-/security-sensitive machinery gets lumped together with vintage electronics. And with expensive mechanical cameras. With computers, smartphones, and appliances which have valuable undamaged components. With brand-new widescreen televisions in the box which the retailer didn't sell but can't sell because a newer model arrived. So much waste in the e-waste (or "e-cycling") industry which can be avoided.
@@pwnmeisterage While what you describe may happen at your local yard, and others as well, I can assure you, the vast majority of recyclers would rather make the extra money reselling (mind you we are not retailers) or at least passing on the material to a better end, so long as the money is there (it is a business) and of course if there are no restrictions on reuse. The problem comes from dealing with people. (again speaking from a non-restricted perspective) I run a recycling center (which requires my entire focus) and not an electronics clearing house and all of the things that come with it. It takes the right approach to be able to "browse" my yard. It is a working, dangerous busy place and the last thing a yard operator needs are shoppers. I say this with respect, but it is the truth. Most yards COULD, if they wanted, but chose not to because of the liability and time consumption. Most yards (perhaps other than the one you mentioned) ultimately have a guy that they trust that they will sit stuff aside for.
The main change of the Plus model was the switch to 16K DRAMs only and the elimination of the three memory select jumpers along the left side of the motherboard. In the earliest days you could buy an Apple ][ with 4K, 8K, or 12K of DRAM. The switch to the two-piece keyboard and change of the character generator ROM due to supply issues were also part of it. At roughly the same time Microsoft had BASIC 1.0 ready, but 4K chip production was ending in favor of 16K chips and there was no need to produce motherboards that hosted 4K DRAM chips. As trivia, Woz said he thought the last thing Jobs designed was the industrial design of the Apple ][ case (I got that from Woz himself).
@@MagesGuild No, Plus models assembled at the very beginning of the transition from the existing rev 4 PCB run had soldered (not socketed) memory select jumpers which forced three banks of 16K each, and removed the ability to host 4K DRAMS as I stated above. That's a hardware difference and a change to the board of the Plus models. As soon as old PCB stock was depleted they moved to boards without the 4K select option altogether which also took 2716 polarity mask ROMs for the character generator because of supply issues with the SIgnetics 2513. That change brought multi-lingual support and future lowercase display. The new two piece keyboard was also phased in here thanks again to supply issues as sales volume was rising, allowing for a 10-key keypad for accountants, world-wide localization of the encoder, support for people with disabilities, and potential to support lowercase entry. When the Plus was introduced, they pulled the A2S0004, A2S0016, A2S0032, and A2S0048 models from production and started pushing the A2S1048 model as the standard configuration with 48K because DRAM prices started falling hard.
@@Peter_S_ Ah yes, that is true. For reference, my original ][+ is date code 7952, serial around 19K, and those jumpers are indeed, not socketed. The thing here though, is that people did modify them, adding sockets. The actual board is identical, and there was nothing that prevented a system owner from adding 4Kx8 RAM if they had it as spare (e.g. from something else), and there were articles that explained how to do it, at the time (that I vaguely recall, as I never hard a reason to use those 4kx1 chips). The funny part is that the base ][ Rev 4s from the same period, and slightly later, were still socketed and available in 4K configurations. I think that I have one from mid 1980 or even 1981 like that. IMO this was not a cost saving measure on the part of Apple, but an attempt to show the 'plus' aspect of the ][+, by only offering 16K, 32K, and 48K base models. If there was a cost saving idea at work, I suspect it was avoiding marketing the wide gamut of RAM options of the base ][, and phasing out the 4kx1 chips as the cost difference has become obsolete. In any case, while you are absolutely right that the jumpers are soldered, there are no electrical differences in the mainboard. The core difference is that in 1979, the ][+ came with AppleSoft as std, and the ][ still had Integer as std. This too was phased out, as once Apple PASCAL was introduced, you needed a language card, and shifting ROMs in Slot 0 became a troublesome process. I wish I had retained the original (Rev 0) mainboard in my base ][ (Serial ~5,000). I have considered trying to source another, or to build one, but neither would be as authentic as the 'upgraded' Rev 4 board that we used at the time. Sadly, because we updated tot he R4, I do not have a specific date code for that machine, but I think it was something around the tune of 7730. I do hope that Adrian doesn't fail to return that Datanetics KB. Slapping a RFI KB into that machine would damage its history. While the Datanetics boards are a gigantic pain in the bottom, the two tone, raised power lamp is what signals this as an early machine, and is very important in historical context. My B&H has the Datanetic KB, too. My 7952 ][+, I long ago upgraded to a 'macro' KB. The power lamp acts as a function key, and every key has a shifted and unshifted BASIC function tied to it. (e.g. Function+C prints CATALOG to the screen). I still have the original KB, I just don't use it as the upgrade--probably rarer than the Datanetics KB itself--is rather useful, and has better switches. :shrug:
The most common reason for a keyboard failure is reversing the ribbon cable connector on either the motherboard or keyboard. It puts -12v onto one of the keyboard's data lines and blows the buffer IC. I can't tell you which IC it is but this has happened to me and I was able to repair the keyboard by replacing the IC. You can simply trace the pins back to see where the -12 volts goes when the cable is reversed. It might explain why the computer was being recycled.
Yes, I did exactly that. I reversed the ribbon cable connector when I plugged the keyboard back into the motherboard, after I had told myself to not reverse the connector! Argh!!! After I reversed the connector, the keyboard sort of worked, but only characters that have control characters. If the character doesn't have a control version, it didn't work.
With the later ALPS keyboard, I have read if someone ever powered up the machine with the ribbon cable installed backward, the 74LS04 or 74LS00 can get fried. The symptom is that the reset key will work but none of the other keys will work. I don't know if the Datanetics keyboards are the same way, but you might check the TTL chips on the keyboard.
So many memories. The first computer I ever owned was an Apple 2e that a bank threw out and 7 year old me asked if I could take it to play with, it still worked fine and was the first time I programmed a basic program.
This video couldn't have come out at a better time for me. Within the last week I started troubleshooting some issues on an Apple II of my own coincidentally with the SAME "7901" marking on the board. I had been using your Apple II Plus videos for guidance.
For the non-autostart ROM Apple IIs, you can boot the floppy drive from the monitor with either "6, Ctrl-P, Return" or "C600G". This will also work on the autostart ROMs too, but obviously not as necessary.
I love the "raw, unscripted, fucked up video, swapping chips instead of checking documentation"-style of repairs in "Adrian's Digital Dungeon"! Made my day!
To hold on the "Velcro" tabs on my Bell and Howell machine, I used 3M Super Strength Molding tape. The kind that holds trim and emblems on automobiles. It can be gotten from your local auto parts store. It has the strength to hold up to separating the "Velcro" and the adhesive holds on the plastic really well.
I'd put my full faith behind 3M adhesive. I had good luck with Gorilla Glue but I haven't taken the cover off too many times since fixing it. If it doesn't hold up, I'll look for that tape.
Have you ever used dual lock from 3M? I use it and it gives a much better hold than velcro. The only drawback is the gap created by the dual lock being around 5mm
Those tabs are called mushroom fasteners, or something like that. It was very common for those to come loose. I think later models used melted plastic posts to hold them down.
@@Mueller3D I guess over decades the adhesive starts to fail, but those are usually pretty reliable. Also worth pointing out is that they usually have different densities / strengths and you can mix different densities when you need something in-between. In my experience, it also takes quite a few removal / insertion cycles before they start to lose their "brand new" grip, quite a reliable product, at least under their intended lifespan.
I still have my 16K Apple II I purchased back in '78 for around $1100. I remember the S/N being around 58xx. Had to use my own cassette tape deck to load the programs. I learned a lot by studying Woz's Monitor code and began writing my own routines. Apple's use of low-cost DIP sockets became a persistent problem and I had to pull ROM and RAM chips to clean up the pins with a pencil eraser in order to get the system to boot. The 6502 was an inexpensive, yet powerful CPU and in later years I designed several 6502-based printer adapters that allowed the use of non-Commodore printers with the Vic-20 and C-64 (including graphics). I actually used my Apple II as a logic scope to analyse Commodore's communication protocol.
If I recall (it has been a while!) the equivalent of pr#6 in the monitor is 6 and hit enter. I think there's an in# equivalent too but didn't use that very often.
Just as a quick note, if it hasn't already been mentioned. From the machine language prompt, you can execute the ROM code on a peripheral card by simply taking the the slot number and sticking it into CX00. So to boot from a disk ][ card in slot 6, you would execute the code starting at C600. This is basically what the PR# command did. IIRC, the 256 bytes of memory in each CX00-CXFF was a simple memory map to the lowest part of the on-board card rom......which for a DISK ][ interface card was a bootstrap loader that would start the disk reading, and copy the first sector into memory, then start execution there.
Hi Adrian. I’d fasten the black, plastic “fake Velcro” things back on with 5 minute epoxy, but make sure the mating surfaces are SPOTLESSLY clean! Once you get them clean, use rubber gloves (clean, of course!) to handle them so you don’t get your fingerprints on them; the oil from your fingers can degrade the adhesive quality of the bond. Now for the tricky part: you need to transfer the location of the black, plastic thingy onto the mounting flanges built into the case of the Apple ][, and mark it with a #2 pencil; don’t use ink of any sort. One way to do this is with honey or pancake syrup; just spread it on the flat underside of the black, plastic thingy, then press the top lid into place on the computer, then lift it off. Use the #2 pencil to trace around where the honey/syrup transferred onto the mounting flange. You can now easily clean it off with hot, soapy water. Do this with the case removed from the bottom section w/the motherboard! Remove the black, plastic thingies from the mating black, plastic thingies on the top lid, and set the top lid aside for now. Repeat the following twice; once for each black plastic thingy: * place the BPT (black plastic thingy) onto the mounting flange on the case, using the locating marks you made with the pencil. * note that the “fake Velcro” part of the BPT is solely in the center, leaving a sort of “ear” (the rounded portion). You’ll need a 3/16” drill bit, and a drill. Drill a hole in the “ear” of the BPT so the center of the hole is at the center of the curvature of the “ear”. Drill the other ear similarly. * make sure there are no burrs around the drilled holes; twirling a #11 X-acto blade in the hole (gently) will work. * place one of the (now drilled) BPTs on the mounting flange on the case in the outline made by the pencil marks, then gently hold it in place with your (gloved) fingers, locate the drilled holes onto the mounting flange with the pencil. Set the BPT aside. * using the hole marks, drill a small pilot hole with a 1/16” drill bit to a depth about 1/16”. Now, use the 3/16” drill, drill the hole out to a depth of about 1/8”. It is important to not drill all the way through; this is a “blind” hole. * use a Q-tip dipped in IPA to clean out the drilled holes (in case there was any oil on the drill bit) in both the mounting flange AND the BPT! * mix up your 5-minute epoxy now, and using a (different) Q-tip, dip it in the epoxy and apply it in the blind holes you drilled earlier. Make sure to fill the holes completely! Slather the mating surface of the mounting flange outlined in pencil with the epoxy, then - visually, line up the holes in the BPT with the epoxy-filled holes in the mounting flange, press it home and make sure the epoxy oozes out, and fills the holes in the BPT. Apply just enough epoxy to these holes so it forms a small, convex dome. * (optional) use a 2-56x1/8 machine screw, and coat the threads with epoxy, then shove it into the hole. This will increase the bond strength, similar to how using rebar in concrete is a good idea. * allow to sit for 24 hours!! Repeat for the other BPT/mounting flange. That f***er should NEVER come off, now! In fact, it may now come loose from the top case (lid) instead! 🤔 Oh, yeah, and you can take the gloves off, now. 🤣
Yup. I surely wouldn't try any CA glue unless you have some accelerant present. ABS and CA glue don't get along that way. A good quality epoxy like DevCon or LocTite will do the job nicely. Use just a bit of 91% IPA to clean. In the absence of the original closures, 3M makes a black plastic Command closure very similar that is service removable (in case you ever do get the originals).
@@horusfalcon DevCon Plastic Welder (the cream coloured stuff specifically) will bond those black clasps to the case so well you'd break the case before you broke the adhesive bond in the future.
when i was a kid i never heard if the apple 2 back in the 80's. until i when to school. my school had an apple 2 & a apple 2c. now year's later in the 90's me & my dad was bumming around in goodwill. i went into the back where they had there electronics & then i saw it they had an apple 2 computer sitting there for $15. so i grabbed it & went up front as fast as i can & i bought it. that was the happiest day of my life.
For reattaching the black plastic Velcro-type tabs, 3M VHB Heavy Duty Mounting Tape 5952 works very well. It's a double-sided tape, which I understand is designed for automotive applications. Probably best to clean the plastic tab and the portion of the case to which you wish to stick it with IPA first.
I loved my Apple //e. This video takes me back to my college days when I was one of the few lucky people to have my own computer. My favorite games were; Castle Wolfenstein, Chop Lifter and Lode Runner. It's great to see a machine like this brought back to life. Thanks for the video!
What people may not know about Oregon is that there is a electronics recycling mandate, so you very, very rarely find old computers of any kind at thrift stores or Goodwill. Any vintage electronics that comes in is immediately destined for the e-waste bin. You pretty much have to literally rescue it as it is being transported....
For years I've been trying to remember a game I liked to play on my Atari 800 back in the day, and all I could remember about it was "bouncing monsters". It's Drol! Thank you Adrian!
Pointless bit of trivia: there are two slightly different versions of DROL for the Atari; the original one uses ANTIC mode F (320x192 mono) and achieves the colours using NTSC composite artifacting, but a later release uses ANTIC mode E (160x192 4 colours), presumably for the PAL market where the artifacting didn't work. Due to how the two modes work the patch was remarkably simple; changing one byte to set the different mode, and add a couple of instructions to set the palette registers, and no modifications to the graphical assets were required. You can use a debugger in an emulator or something like the Turbo Freezer on real hardware to perform the same trick on other games that made use of NTSC artifacting (e.g. Ultima III) to stop them looking like ass in PAL mode. :P
Several years ago, my nephew cleaned out a country school and gave me 14 apple II machines complete with monitors, printers, drives and a ton of software. I knew of some home schooling folks and called them, the computeres were donated by me to those home school kids who loved them. Sort of wish I had them now, all worked fine when they left my house.
I used to have a job programming these for a commodity market trading software. It was an Apple II with a 128K memory card and an accelerator card. The basic had been modified to swap in code segments so you could have a larger program than would normally be permitted. It was eventually replaced by an IBM PC with most customers. There was a market quote box that would interface to the Apple.
Some how the mix of your semi haphazard approach mixed with your methodical troubleshooting, and light hearted off the cuff commentary all makes for a great viewing experience! Thanks Adrian.
My first computer was an APFLE ][. Yes, APFLE. It was a clone my dad and brother built. Whoever copied the rom must have made the change, I'll have to ask them more about it.
I did a high school co-op placement with an Apple Education pilot project with the Carleton Board of Education in Ottawa, and then I did some volunteer work with them. I also had a couple of friends who had Apples as well. I troubleshot dozens of Apples ][ and ][+ machines since we didn't have any technicians. Since they ran so hot, and we were running them all day long, and sometimes late until the night, we had side fans that kept the machine cool. But they were notorious for chip creap...that is, as they heated and cooled, the would work themselves out of the sockets, and eventually cause errors of total failures. If we had a computer that didn't boot, the standard fix was to go and gently push down all of the chips so that they were well seated in their sockets. The next step, if the machine didn't boot was to feel the chips while the system was on, and see if there were any that were excessively hot, like too hot to touch. Then we would swap the chip with another system, and if it booted, then we knew we had a bad chip. This troubleshooting regimen solved about 90% of the problems we encountered. Other, more esoteric problems were the power supplys that failed, or the most common problem, being in a rush to get systems ready for a class, and needing a I/O card to do the class, and pulling out the card or putting in the card without making doubly sure the machine was turned off. I would later go on to form a small side business with a friend where we bought clone expansion boards and componants in Toronto on College St., where all the computer shops were, and then assemble them at home to sell to the computer stores around Ottawa. My friend had taught himself to design computers and peripherals, and worked most summers at Bell Northern Research, which later became Nortel. I ran a computer camp at a local community centre, and from that income was able to buy the parts and build my own Apple ][+ clone. Some of my favourite games were Loderunner, Joust, Bilestode, Wavy Navy and Wizardry, plus the original Adeventure (aka The Collosal Cave), and later, Hitchhikers Guide to the Galaxy. I also ran CP/M, and taught myself dBase II, and made some money over the years doing database programming. They were fun times...
This brings back such nostalgia.....I had one, and was *so* excited to link it up with my "blazingly fast" full duplex 300 baud Hayes Micromodem so I could call various BBS's. Ahhhhh. Memories.
Love watching your videos. I went to DeVry, (Ohio Institute of Technology), '79-'81. The Apple II just came out as did the TRS-80 Model 1. The school didn't teach much computer stuff back then because PC's were so new. They did have a Data Processing class where they would feed code into an IBM mainframe via punch cards and then run their code. We also had a room of terminals that ran a version of BASIC that was written by one of my teachers. My first computer was the APF Imagination Machine. I was in my first year at DeVry so I knew very little about actual theory and troubleshooting. When I first unboxed and plugged the computer in, it would run for a minute or so then shut down. Being the geek I was, I pinpointed a device in a TO-220 package that was loosely attached to a heatsink. My first thought was, "how is that going to work if it can't dissipate the heat? So, I snugged up the screw and I was in business! I'm thinking it was a regulator. Your videos bring back some fond memories. I had a couple C-64's, an Amiga 500 and an A1200 which I loved. I had the GVP sidecar for the A1200 with a 120MB drive in it! I also had the upgraded Agnus chip and the 2.0 Kickstart ROM.
Hi Adrian. I really enjoyed this video, incredible stuff. It's really rare o see a computer from 1978 in such a mint condition. By the way you can boot the floppy from machine monitor by typing "6 ctrl-p enter" combination.
Man....I learn so much from your videos. In the more mechanical world...this tapping would be called "percussive maintenance". Glad to see it can apply elsewhere :) thank you for all you do :)
Either 6[ctrlP] to emulate PR#6, or 6{ctrlK] to emulate IN#6. Both of those should kick of a slot 6 boot. Also, C600G should have also worked.... I thought it was ctrlC to get from the monitor back to the BASIC prompt, but if ctrlB works, cool. You can also get to BASIC (usually, not always) by calling 3D0G. :)
CTRL-B is a “cold start” into BASIC, while CTRL-C is a “warm start”. I don’t remember the exact differences off the top of my head, but a cold start might clear any program and reset the I/O vectors (so it might disconnect DOS if you were booted into it).
OBS is kinda complicated when it comes to capturing multiple sources then editing them out. Basically when I want to capture multiple full size 1080p sources I double the width resolution of the canvas then set the output to either be the same or scale it accordingly to the resolution I want. So basically 3840x1080 instead of 1920x1080. Then after I double it I put my two sources I want to capture next to each other in the full resolution they need. Bit rates might have to change due to that but I have not found it changes much. Now when you go to edit I recommend either using ffmpeg or handbrake to split the clips to be two different video files meaning cropping 1920px left for one then right for the other then putting it both clips in your video editing software so that the video editing software doesn’t have to handle cropping cause they can be weird about it sometimes. I hope this helps and if you do have any questions I can help as much as I can
I spent many years using an Apple II, connected computer to small heaters, speakers, microphone and at one stage carried out diagnostics on a robotic motherboard for a robotics company. Interfacing with external chips was so easy. Towards the end was using a 5MB disc drive. I used to cut out a notch on the floppy discs so I could use both sides, others will remember this too I guess. A lovely computer. (Not sure if it was a plus)
As far as fixing hot really chips go, back when I was working on some old Mod-Comp J1 and J2 machines, I found you could swap out some of the really hot current hog 74 and 74LS series chips with CMOS equivalents. The Mod_Comp machines used several rows of 74170 4x4 Register File chips. These chips ran really hot and were prone to frequent failure. Even the Mil Spec version of the 74170 chips failed. Swapping the TTL chips to CMOS greatly reduced the load on the power supply, made the machines run much cooler and made them more reliable. Changing current hogging magnetic core memory planes to solid state memory further reduced temps and increased reliability. I also found the same issues you found with the TI chip lead oxidation. The leads on some really old TI chips in those Mod-Comp machines would actually become so thin and brittle from oxidation that they would literally fall apart when you tried to remove them from the sockets! Heat and a high humidity environment would really do a number on them.
Note the MM5740 is not a microcontroller, it was a National Semiconductor dedicated Keyboard Encoder chip, which was pretty commonly used for parallel keyboards of the time. I seem to recall the MM5740AAF as most commonly used for ASCII encoded parallel keyboards. Note also, that these keyboard encoder chips were dual supply, requiring both 5V and a -12V supply. So you might also want to check both power supply voltages are good.
I still have our apple ii+ from the early 80's with 2 floppy drives. When we bought it, it was for educational use only and no games allowed but that changed over time as friends at school gave copies out and that's how we got them and mom and dad didn't mind but then did buy a few later.
I decided early on that DeOxit'ing every socket was what I needed to resurrect my original Apple II that we bought in '79...really dodgy until I did that. Looking forward to your 2nd channel PS episode. You have to drill out the rivets in the older supply to get in and I found it didn't have a RIFA cap at all that I was ready to replace.
@@raggededge82 You're absolutely right but it sure does go a long way towards solving many problems. I even dab 100% onto battery terminals which is most likely severe overkill but it makes me feel better! Too bad it doesn't cure "Dura-Leaks" these days. And yeah, mums the word! 😉
4:50: If you compare those velcro-ish pads on your friend's machine with those shown on the cover of The Apple II Circuit Description book (cf. 15:02), you can see that the latter appear to be plastic-riveted, which suggests a design change at some point, meaning this also was an issue back then. Not that this solves the issue, and I'm not sure whether the rivets or glue came first, but I thought I'd point it out. I mean, one way to solve the issue for sure would be to very carefully drill holes through both the pads and the case, and to use nuts and low-profile flat-head bolts and maybe washers to screw the pads down, but that mechanically sound solution would probably be unacceptable from an artefact preservation standpoint.
Today, the most significant difference between a rev1 and rev0 (with ventless lid) is resale price - a couple of hundred $$ versus a few-to-many thousand for rev0/ventless. :) Dodgy Socket is also the name of my favorite band.
Hi Adrian, in monitor just use "c600g" (slot 6), another way type "6, then CTRL+K (or P)+Enter". Regard of the hot chip, as I remember when 1982 summer holiday, I need to put a fan to blow the RAM chips or hang up every 20 minutes, and I did not have original Apple ][+ but a clone.
It's a good thing the computer was working perfectly :) That made it easy to find all the bad connections and chips! Great video. Your patience with Apple computers amazes me!
Apple ][ case and motherboard Woz the most ingenious design I have ever come across in the 8-bit computing era especially when their was limited technology around to build and put together such equipment. Hands down the apple ][ was so neat on appearance.
Speaking of TI chips getting oxidised, I have a TI DS990 Model 1, and pretty much every single TI chip inside has black legs! All the 4116 RAM ICs needed to be cleaned up with a fiberglass pen. Silly machine still doesn't want to run correctly. Strangely, it will throw an error 'LOAD ERROR 22' when I turn it on, but if I turn it off, wait a few seconds and turn it on, it wont throw any errors, it'll just freeze. It'll be like that for a few hours, and then if I try it again, it will show the 'LOAD ERROR 22' error again. Also, I've not found any documentation which can tell me what the error number means. Ahhh TI, so brilliantly amazing, but their execution always seems a bit off in places. Really enjoyed this video! It is very interesting to see how Apple revised the Apple II over the models run. It got me itching to muck around with a few old machines I have here. The TI is staring at me, but I have an iAPX 432 system that needs some attention.
It was a great video. The Apple II was the first computer I ever touched as a freshman in HS in 1980. Brought back a lot of memories not to mention all the troubleshooting on systems after electronics school for oxidation issues.
One of my first troubleshooting steps with digital equipment is to check the resistance readings of the voltage rails at the power connector and compare to a known good unit if available before the first power up. That way you can minimize the chance of releasing the smoke that’s sealed into the parts if it turns out to have a short in it.
I had an original rev. 0 Apple II. There was an article, I believe in Byte Magazine, showing the modifications necessary for 6-color hi-res graphics mode. I did that mod a couple of times; originally, I used a method that involved sticking wire-wrap sockets into the chip sockets in order to avoid cutting any traces on the motherboard. However, that eventually made the computer flaky (wire-wrap legs are much thicker than chip legs), so I later re-did the mod with directly soldered wires. I lived on that computer from middle school through high school.
@43:12 The machine language equivalent of PR#6 is C600G. C600 is the address of the Disk Controller ROM in Slot 6. 'G' is Go, as in run it. If, for example, you moved the disk controller to Slot 4, 5 or Slot 7 it would be C400, C500 or C700 respectively.
It was amazing to me to see how friendly and well thought out the design of the A2 for repairability. Now days you can't even open an Apple. (yes, I know you can, but you get the point.)
I worked on these when they were new (8th grade) and they commonly had to be opened up and have all the chips reseated. Right away when I saw the monitor I was shouting at the screen "3D0G!!!" which is another way to get back to basic. It was the procedure before the autobot rooms came out - turn on -> 3D0G -> PR#6 and then you'd be booted.
I came across your channel and found it quite interesting. I found it really interesting when I found this Apple ][ restoration video you put out. I have no question for you, I'm just telling you my Apple story. I am the original owner of an Apple Integer machine that I bought in 1978-ish, it's in the original box in my closet, and I used it every day until about '95 when I made the jump to PC so I could play games Lol The case and innards are in mint condition, except for in the early '80s when I opened the lid and a pencil fell in the crack and damaged a circuit (thank goodness it was turned off). My friend who owned a computer business (who sold me the computer, btw, his brother bought the first Apple ][ Computer in Canada (Woz signed the back of his at a computer show)) also fixed it, so thusly I have a resistor on the motherboard. It's been many years since I've opened it up, and when I did, it worked great (fantastic machine), but if I recall correctly there's an Apple 2+ card, a memory card, and a midi card, maybe a couple of others. Over the years I had hundreds (maybe thousands) of hours of fun with this computer. I'm not looking to sell it, I just thought you and your viewers might like a testimonial. Cheers!! 😬 Great video by the way!
Those case holders look like the 3M DUAL LOCK ipass transponder tape/pads. They come with adhesive that works on car windshields/temp swings/yanking on transponder.
Yep, Control-P in the monitor is the equivalent of PR# in BASIC. And Control-K is like IN#. (The mnemonic is control-P sets where you Print, and control-K sets what Keyboard you use for input.) So you can use either 6 Control-P Return or 6 Control-K Return, since the standard Disk ][ controller will attempt to boot if you redirect either output or input to it. (And on a //e or later you can actually type 6 Up Arrow Return, since the up arrow maps to Control-K. But there's no up/down arrows on the ][ and ][+ keyboards.)
Lots of memories of those Apple II machines. Our local schools got them before they had an IT department. Math teacher wife was the first teacher in the county to push the use of computers in the classroom. She applied for and got a federal grant to buy some of the first computers used in our county schools. The first were TRS-80's immediately followed with the Apple II's and then Franklin's, (an Apple II knockoff). Back in those days she brought allot of those machines home for me to fix. I did find a couple of design issues with the Apple II that were made even worse in the Franklin's. I can't remember whether it was data or address lines that didn't use pull-up resistors but this caused intermittent crashes with one particular piece of education software. The Franklin motherboard was a carbon copy of the Apple II but it was physically a bit larger. As a result of the increased physical size, increased line length increased impedance and capacitive loading. This caused system timing issues. I seem to remember that one of the address or data lines ran all the way around the right side of the motherboard, down the bottom and back up the left side. For the most part the Apple II would run this particular piece of software with only occasional crashes. The Franklin's were another matter. I used a couple of 2.2k pull-up resistors and that fixed both machines. Another issue was the colors on another piece of educational software was flaky. Color rendition for that piece of software was poor on the Apple II and really awful on the Franklin. I can't remember the values or exactly where they were installed but a ceramic cap and a resistor installed somewhere around the, "Color Trim" variable cap fixed both the Franklin and the Apple II. This fix also improved colors on all other software.
That beep that the Apple II makes brings back memories. That was the first computer I had used and I was 5 at the time. Oh and there were certain programs that would only run when the disk controller card was indeed in slot 6.
I had an Apple II+ as my first computer. This was interesting to see an earlier one. Looking forward to seeing if it can be fully whole with that original keyboard.
The Apple II Europlus was the first computer I ever used in 1980. The socketed chips were a mixed blessing we used to have to reseat the chips from time to time.
I pulled a C64 out of an e-waste container just half a year ago, and a Rockwell AIM-65 and a VIC-20 about 2 years ago. People still don't know what they're throwing away. About 6 years ago I found two homebrew Apple ][+ bootlegs in the e-waste together with a Roland SH-2000 and a Jupiter-4 (yes!). I spoke to the owner and he actually knew what he was throwing away (and what it was worth on eBay) but didn't care about the four digit prices...
That's the first time I've seen the inside of an original Apple ][ since I was in 5th grade, in 1978. Ours had a Basic board, so it dropped right into Basic on power up. We were so happy when we got the disc controller and a floppy drive, because loading cassettes SUCKS.
@Adrian's Digital Basement I hope this information helps: Joe of Joe's Computer Museum is selling a replacement keyboard encoder chip for the older Apple II computers on his website. It has been tested on a few of the Apple II models, so why not give it a try? He has only 1 left as of this writing, though...
I and probably other people find annoying there's light coming from top over you and theres a light t-shirt or shirt and the camera darkens your face. Otherwise, another EXCELLENT video where you go through things and we love.
The Apple ][ Circuit Description book is a must have book for anyone working on Apple ][, and ][+ computers. I no longer have my Apple computers but I still have that book and many other of the Apple books for the machine. You can access the 256 byte "boot" code of a board in a slot at starting at address Cn00, where n is the slot number. To do the equivalent of PR#6 from the monitor you type C600G.
18:30 The 6502 using its bus on only one half of each clock could simplify a video interface somewhat. But it also slowed the whole execution (clock speed) down, as the full memory access time was bound to just half a clock. In practice only about 60% of that time, or 30% of a full period, due to the design (and the nMOS transistors used). So although the 6502 used about 2-3 times as few clocks as differently designed processors, it needed about six times as fast memory ICs compared to them, to reach the same "clock speed". (Other processors usually allowed two full clock periods for memory access.) That's one of the reasons why 6800 and 6502 computers were so slowly clocked. The 6502 line also lacked all sorts of 16-bit arithemetics, unlike its contemporaries. It needed a lot of bus traffic just to add or subtract two 16-bit numbers. So nothing was gained really. Other simple computers typically used a WAIT signal to halt the CPU when video memory was accessed, which was a much smaller loss of performance than statically dedicating 50% of the bus to video access. More advanced computers used FIFO buffers and/or a wider bus to read out video data in the gaps always left by CPU execution.
I still have my Apple ][+ that i bought brand new. So new that it's an Apple ][ like this one, upgraded to the Plus by the computer store with ROMs from Apple. I even have the faux leather carrying bag/case for it! Watching the vid will have to wait, I'm busy at the moment, but I hope to watch it and get inspired to check mine out and make sure it still works!
I grew up with the Apple ]['s in elementary school back in the late-80s and early-90s, and to this day I still kick myself in the pants for not checking in to see if/when they were being sent off to e-waste. But I did end up buying myself both an Apple ][ Plus and an Apple //GS just recently for a very reasonable price, along with a FloppyEmu, and all my elementary school memories came back... it was great. I miss the old Apple Computer, Inc. days, when you can tinker and replace parts with ease. Modern Apple, Inc. feels like a whole other company.
@@nickfifteen Well, in many ways it _is_ a different company. But then the world and the computer market has changed, too. Computers tend to be more of an appliance now. Back then there was a lot more tinkering and expanding. That still happens, just in a different way.
![BOWKYLION - วิงวอน (ex-change) [Official MV]](http://i.ytimg.com/vi/cLdnZWDaO-w/mqdefault.jpg)
2:21 Yes, it does happen now days. I operate a large nationwide e-waste facility and I am proud to have rescued 100's of retro pieces from destruction while simultaneously building my own collection. My most recent save was just this week where I pulled a Commodore Plus4 still in the box from the pile.
Extremely rewarding job, it would seem :) I wish I was in your position :D
I worked in one of those places for exactly one day.
Everything ripped apart, stripped, separated, crushed, binned. No exceptions.
They had contracts with governmental datacenters so they had flat zero tolerance policy which absolutely prohibited any kind of salvage because of data privacy concerns.
@@pwnmeisterage Very true. There will always be clients who demand total destruction with no exceptions typically involving more modern technology. Whereas the vintage stuff tends to come from estate cleanouts and recycling drives where re-use is rarely an issue and in some situations, encouraged.
@@boardsort It is true. But also sad that the privacy-/security-sensitive machinery gets lumped together with vintage electronics. And with expensive mechanical cameras. With computers, smartphones, and appliances which have valuable undamaged components. With brand-new widescreen televisions in the box which the retailer didn't sell but can't sell because a newer model arrived.
So much waste in the e-waste (or "e-cycling") industry which can be avoided.
@@pwnmeisterage While what you describe may happen at your local yard, and others as well, I can assure you, the vast majority of recyclers would rather make the extra money reselling (mind you we are not retailers) or at least passing on the material to a better end, so long as the money is there (it is a business) and of course if there are no restrictions on reuse. The problem comes from dealing with people. (again speaking from a non-restricted perspective) I run a recycling center (which requires my entire focus) and not an electronics clearing house and all of the things that come with it. It takes the right approach to be able to "browse" my yard. It is a working, dangerous busy place and the last thing a yard operator needs are shoppers. I say this with respect, but it is the truth. Most yards COULD, if they wanted, but chose not to because of the liability and time consumption. Most yards (perhaps other than the one you mentioned) ultimately have a guy that they trust that they will sit stuff aside for.
New shirt? "DEOXIT THAT SOCKET!" heheh
yes; Deoxit That Socket! (shirt would not get "© flagged" if you put a picture of an ox between "de-" and "-it")
Anything like "Don't copy that floppy!"?
The main change of the Plus model was the switch to 16K DRAMs only and the elimination of the three memory select jumpers along the left side of the motherboard. In the earliest days you could buy an Apple ][ with 4K, 8K, or 12K of DRAM. The switch to the two-piece keyboard and change of the character generator ROM due to supply issues were also part of it. At roughly the same time Microsoft had BASIC 1.0 ready, but 4K chip production was ending in favor of 16K chips and there was no need to produce motherboards that hosted 4K DRAM chips. As trivia, Woz said he thought the last thing Jobs designed was the industrial design of the Apple ][ case (I got that from Woz himself).
No, the early ][+ had the same trev 4 mainboard. The only major difference was Applesoft BASIC ROMs as std.
@@MagesGuild No, Plus models assembled at the very beginning of the transition from the existing rev 4 PCB run had soldered (not socketed) memory select jumpers which forced three banks of 16K each, and removed the ability to host 4K DRAMS as I stated above. That's a hardware difference and a change to the board of the Plus models. As soon as old PCB stock was depleted they moved to boards without the 4K select option altogether which also took 2716 polarity mask ROMs for the character generator because of supply issues with the SIgnetics 2513. That change brought multi-lingual support and future lowercase display. The new two piece keyboard was also phased in here thanks again to supply issues as sales volume was rising, allowing for a 10-key keypad for accountants, world-wide localization of the encoder, support for people with disabilities, and potential to support lowercase entry. When the Plus was introduced, they pulled the A2S0004, A2S0016, A2S0032, and A2S0048 models from production and started pushing the A2S1048 model as the standard configuration with 48K because DRAM prices started falling hard.
@@Peter_S_ Ah yes, that is true. For reference, my original ][+ is date code 7952, serial around 19K, and those jumpers are indeed, not socketed. The thing here though, is that people did modify them, adding sockets. The actual board is identical, and there was nothing that prevented a system owner from adding 4Kx8 RAM if they had it as spare (e.g. from something else), and there were articles that explained how to do it, at the time (that I vaguely recall, as I never hard a reason to use those 4kx1 chips).
The funny part is that the base ][ Rev 4s from the same period, and slightly later, were still socketed and available in 4K configurations. I think that I have one from mid 1980 or even 1981 like that. IMO this was not a cost saving measure on the part of Apple, but an attempt to show the 'plus' aspect of the ][+, by only offering 16K, 32K, and 48K base models.
If there was a cost saving idea at work, I suspect it was avoiding marketing the wide gamut of RAM options of the base ][, and phasing out the 4kx1 chips as the cost difference has become obsolete.
In any case, while you are absolutely right that the jumpers are soldered, there are no electrical differences in the mainboard. The core difference is that in 1979, the ][+ came with AppleSoft as std, and the ][ still had Integer as std. This too was phased out, as once Apple PASCAL was introduced, you needed a language card, and shifting ROMs in Slot 0 became a troublesome process.
I wish I had retained the original (Rev 0) mainboard in my base ][ (Serial ~5,000). I have considered trying to source another, or to build one, but neither would be as authentic as the 'upgraded' Rev 4 board that we used at the time. Sadly, because we updated tot he R4, I do not have a specific date code for that machine, but I think it was something around the tune of 7730.
I do hope that Adrian doesn't fail to return that Datanetics KB. Slapping a RFI KB into that machine would damage its history. While the Datanetics boards are a gigantic pain in the bottom, the two tone, raised power lamp is what signals this as an early machine, and is very important in historical context.
My B&H has the Datanetic KB, too. My 7952 ][+, I long ago upgraded to a 'macro' KB. The power lamp acts as a function key, and every key has a shifted and unshifted BASIC function tied to it. (e.g. Function+C prints CATALOG to the screen). I still have the original KB, I just don't use it as the upgrade--probably rarer than the Datanetics KB itself--is rather useful, and has better switches. :shrug:
The most common reason for a keyboard failure is reversing the ribbon cable connector on either the motherboard or keyboard. It puts -12v onto one of the keyboard's data lines and blows the buffer IC. I can't tell you which IC it is but this has happened to me and I was able to repair the keyboard by replacing the IC. You can simply trace the pins back to see where the -12 volts goes when the cable is reversed. It might explain why the computer was being recycled.
The most common issue is DC50 switches, not the matrix IC.
Yes, I did exactly that. I reversed the ribbon cable connector when I plugged the keyboard back into the motherboard, after I had told myself to not reverse the connector! Argh!!! After I reversed the connector, the keyboard sort of worked, but only characters that have control characters. If the character doesn't have a control version, it didn't work.
With the later ALPS keyboard, I have read if someone ever powered up the machine with the ribbon cable installed backward, the 74LS04 or 74LS00 can get fried. The symptom is that the reset key will work but none of the other keys will work.
I don't know if the Datanetics keyboards are the same way, but you might check the TTL chips on the keyboard.
ou know, in over forty years of servicing these machines, I have never encountered that specific issue., Fascinating.
So many memories.
The first computer I ever owned was an Apple 2e that a bank threw out and 7 year old me asked if I could take it to play with, it still worked fine and was the first time I programmed a basic program.
haha aww that's so sweet
Yes. So many memories.
Just watched the whole video. Nothing like chilling and watching retro tech repair videos.
I love your channels because you clearly make content for the love of it, not to please an algorithm. Thanks Adrian!
This video couldn't have come out at a better time for me. Within the last week I started troubleshooting some issues on an Apple II of my own coincidentally with the SAME "7901" marking on the board. I had been using your Apple II Plus videos for guidance.
For the non-autostart ROM Apple IIs, you can boot the floppy drive from the monitor with either "6, Ctrl-P, Return" or "C600G". This will also work on the autostart ROMs too, but obviously not as necessary.
I love the "raw, unscripted, fucked up video, swapping chips instead of checking documentation"-style of repairs in "Adrian's Digital Dungeon"! Made my day!
It's pretty artistic in a way
To hold on the "Velcro" tabs on my Bell and Howell machine, I used 3M Super Strength Molding tape. The kind that holds trim and emblems on automobiles. It can be gotten from your local auto parts store. It has the strength to hold up to separating the "Velcro" and the adhesive holds on the plastic really well.
I'd put my full faith behind 3M adhesive. I had good luck with Gorilla Glue but I haven't taken the cover off too many times since fixing it. If it doesn't hold up, I'll look for that tape.
Have you ever used dual lock from 3M? I use it and it gives a much better hold than velcro. The only drawback is the gap created by the dual lock being around 5mm
Those tabs are called mushroom fasteners, or something like that. It was very common for those to come loose. I think later models used melted plastic posts to hold them down.
@@Mueller3D Yes, at 15:35 you can see those, in the photo on the front cover of the book. To repair the stick-on ones, I would use the JB weld epoxy.
@@Mueller3D I guess over decades the adhesive starts to fail, but those are usually pretty reliable. Also worth pointing out is that they usually have different densities / strengths and you can mix different densities when you need something in-between. In my experience, it also takes quite a few removal / insertion cycles before they start to lose their "brand new" grip, quite a reliable product, at least under their intended lifespan.
I still have my 16K Apple II I purchased back in '78 for around $1100. I remember the S/N being around 58xx. Had to use my own cassette tape deck to load the programs. I learned a lot by studying Woz's Monitor code and began writing my own routines. Apple's use of low-cost DIP sockets became a persistent problem and I had to pull ROM and RAM chips to clean up the pins with a pencil eraser in order to get the system to boot.
The 6502 was an inexpensive, yet powerful CPU and in later years I designed several 6502-based printer adapters that allowed the use of non-Commodore printers with the Vic-20 and C-64 (including graphics). I actually used my Apple II as a logic scope to analyse Commodore's communication protocol.
If I recall (it has been a while!) the equivalent of pr#6 in the monitor is 6 and hit enter. I think there's an in# equivalent too but didn't use that very often.
Yep. 6 control-i was the equivalent of IN#6.
Just as a quick note, if it hasn't already been mentioned. From the machine language prompt, you can execute the ROM code on a peripheral card by simply taking the the slot number and sticking it into CX00. So to boot from a disk ][ card in slot 6, you would execute the code starting at C600. This is basically what the PR# command did.
IIRC, the 256 bytes of memory in each CX00-CXFF was a simple memory map to the lowest part of the on-board card rom......which for a DISK ][ interface card was a bootstrap loader that would start the disk reading, and copy the first sector into memory, then start execution there.
Yes. From the monitor ROM, you would type "C600G" to jump ("go") to C600.
This video was fantastic despite all the technical issues. Your charisma and passion for these machines carries it.
Hi Adrian. I’d fasten the black, plastic “fake Velcro” things back on with 5 minute epoxy, but make sure the mating surfaces are SPOTLESSLY clean! Once you get them clean, use rubber gloves (clean, of course!) to handle them so you don’t get your fingerprints on them; the oil from your fingers can degrade the adhesive quality of the bond.
Now for the tricky part: you need to transfer the location of the black, plastic thingy onto the mounting flanges built into the case of the Apple ][, and mark it with a #2 pencil; don’t use ink of any sort. One way to do this is with honey or pancake syrup; just spread it on the flat underside of the black, plastic thingy, then press the top lid into place on the computer, then lift it off. Use the #2 pencil to trace around where the honey/syrup transferred onto the mounting flange. You can now easily clean it off with hot, soapy water. Do this with the case removed from the bottom section w/the motherboard!
Remove the black, plastic thingies from the mating black, plastic thingies on the top lid, and set the top lid aside for now.
Repeat the following twice; once for each black plastic thingy:
* place the BPT (black plastic thingy) onto the mounting flange on the case, using the locating marks you made with the pencil.
* note that the “fake Velcro” part of the BPT is solely in the center, leaving a sort of “ear” (the rounded portion). You’ll need a 3/16” drill bit, and a drill. Drill a hole in the “ear” of the BPT so the center of the hole is at the center of the curvature of the “ear”. Drill the other ear similarly.
* make sure there are no burrs around the drilled holes; twirling a #11 X-acto blade in the hole (gently) will work.
* place one of the (now drilled) BPTs on the mounting flange on the case in the outline made by the pencil marks, then gently hold it in place with your (gloved) fingers, locate the drilled holes onto the mounting flange with the pencil. Set the BPT aside.
* using the hole marks, drill a small pilot hole with a 1/16” drill bit to a depth about 1/16”. Now, use the 3/16” drill, drill the hole out to a depth of about 1/8”. It is important to not drill all the way through; this is a “blind” hole.
* use a Q-tip dipped in IPA to clean out the drilled holes (in case there was any oil on the drill bit) in both the mounting flange AND the BPT!
* mix up your 5-minute epoxy now, and using a (different) Q-tip, dip it in the epoxy and apply it in the blind holes you drilled earlier. Make sure to fill the holes completely! Slather the mating surface of the mounting flange outlined in pencil with the epoxy, then - visually, line up the holes in the BPT with the epoxy-filled holes in the mounting flange, press it home and make sure the epoxy oozes out, and fills the holes in the BPT. Apply just enough epoxy to these holes so it forms a small, convex dome.
* (optional) use a 2-56x1/8 machine screw, and coat the threads with epoxy, then shove it into the hole. This will increase the bond strength, similar to how using rebar in concrete is a good idea.
* allow to sit for 24 hours!!
Repeat for the other BPT/mounting flange. That f***er should NEVER come off, now! In fact, it may now come loose from the top case (lid) instead! 🤔 Oh, yeah, and you can take the gloves off, now. 🤣
Yup. I surely wouldn't try any CA glue unless you have some accelerant present. ABS and CA glue don't get along that way. A good quality epoxy like DevCon or LocTite will do the job nicely. Use just a bit of 91% IPA to clean.
In the absence of the original closures, 3M makes a black plastic Command closure very similar that is service removable (in case you ever do get the originals).
@@horusfalcon DevCon Plastic Welder (the cream coloured stuff specifically) will bond those black clasps to the case so well you'd break the case before you broke the adhesive bond in the future.
when i was a kid i never heard if the apple 2 back in the 80's. until i when to school. my school had an apple 2 & a apple 2c. now year's later in the 90's me & my dad was bumming around in goodwill. i went into the back where they had there electronics & then i saw it they had an apple 2 computer sitting there for $15. so i grabbed it & went up front as fast as i can & i bought it. that was the happiest day of my life.
For reattaching the black plastic Velcro-type tabs, 3M VHB Heavy Duty Mounting Tape 5952 works very well. It's a double-sided tape, which I understand is designed for automotive applications. Probably best to clean the plastic tab and the portion of the case to which you wish to stick it with IPA first.
I use the 3M VHB 5952 as well for various projects and I definitely agree, it's incredibly strong.
I loved my Apple //e. This video takes me back to my college days when I was one of the few lucky people to have my own computer. My favorite games were; Castle Wolfenstein, Chop Lifter and Lode Runner. It's great to see a machine like this brought back to life. Thanks for the video!
I love the Apple II. It's one of the precious few home computers that's older than I am.
What people may not know about Oregon is that there is a electronics recycling mandate, so you very, very rarely find old computers of any kind at thrift stores or Goodwill. Any vintage electronics that comes in is immediately destined for the e-waste bin. You pretty much have to literally rescue it as it is being transported....
For years I've been trying to remember a game I liked to play on my Atari 800 back in the day, and all I could remember about it was "bouncing monsters". It's Drol! Thank you Adrian!
Pointless bit of trivia: there are two slightly different versions of DROL for the Atari; the original one uses ANTIC mode F (320x192 mono) and achieves the colours using NTSC composite artifacting, but a later release uses ANTIC mode E (160x192 4 colours), presumably for the PAL market where the artifacting didn't work. Due to how the two modes work the patch was remarkably simple; changing one byte to set the different mode, and add a couple of instructions to set the palette registers, and no modifications to the graphical assets were required. You can use a debugger in an emulator or something like the Turbo Freezer on real hardware to perform the same trick on other games that made use of NTSC artifacting (e.g. Ultima III) to stop them looking like ass in PAL mode. :P
Thanks Adrian. Great video. Seeing you run into the kind of issues I experience when repairing something is actually a lot of help.
Several years ago, my nephew cleaned out a country school and gave me 14 apple II machines complete with monitors, printers, drives and a ton of software. I knew of some home schooling folks and called them, the computeres were donated by me to those home school kids who loved them. Sort of wish I had them now, all worked fine when they left my house.
I used to have a job programming these for a commodity market trading software. It was an Apple II with a 128K memory card and an accelerator card. The basic had been modified to swap in code segments so you could have a larger program than would normally be permitted. It was eventually replaced by an IBM PC with most customers. There was a market quote box that would interface to the Apple.
I remember learning to program on those in middle school. That was one of my favorite classes of all times.
Mine too. My computer teacher was the absolute best teacher I'd ever had, too. Loved her.
Some how the mix of your semi haphazard approach mixed with your methodical troubleshooting, and light hearted off the cuff commentary all makes for a great viewing experience! Thanks Adrian.
My first computer was an APFLE ][. Yes, APFLE. It was a clone my dad and brother built. Whoever copied the rom must have made the change, I'll have to ask them more about it.
I did a high school co-op placement with an Apple Education pilot project with the Carleton Board of Education in Ottawa, and then I did some volunteer work with them. I also had a couple of friends who had Apples as well. I troubleshot dozens of Apples ][ and ][+ machines since we didn't have any technicians. Since they ran so hot, and we were running them all day long, and sometimes late until the night, we had side fans that kept the machine cool. But they were notorious for chip creap...that is, as they heated and cooled, the would work themselves out of the sockets, and eventually cause errors of total failures. If we had a computer that didn't boot, the standard fix was to go and gently push down all of the chips so that they were well seated in their sockets. The next step, if the machine didn't boot was to feel the chips while the system was on, and see if there were any that were excessively hot, like too hot to touch. Then we would swap the chip with another system, and if it booted, then we knew we had a bad chip. This troubleshooting regimen solved about 90% of the problems we encountered. Other, more esoteric problems were the power supplys that failed, or the most common problem, being in a rush to get systems ready for a class, and needing a I/O card to do the class, and pulling out the card or putting in the card without making doubly sure the machine was turned off. I would later go on to form a small side business with a friend where we bought clone expansion boards and componants in Toronto on College St., where all the computer shops were, and then assemble them at home to sell to the computer stores around Ottawa. My friend had taught himself to design computers and peripherals, and worked most summers at Bell Northern Research, which later became Nortel. I ran a computer camp at a local community centre, and from that income was able to buy the parts and build my own Apple ][+ clone. Some of my favourite games were Loderunner, Joust, Bilestode, Wavy Navy and Wizardry, plus the original Adeventure (aka The Collosal Cave), and later, Hitchhikers Guide to the Galaxy. I also ran CP/M, and taught myself dBase II, and made some money over the years doing database programming. They were fun times...
This brings back such nostalgia.....I had one, and was *so* excited to link it up with my "blazingly fast" full duplex 300 baud Hayes Micromodem so I could call various BBS's.
Ahhhhh. Memories.
Looking forward to see the keyboard and the PSU on the second channel!
Wow, what a clean example!
Love watching your videos. I went to DeVry, (Ohio Institute of Technology), '79-'81. The Apple II just came out as did the TRS-80 Model 1. The school didn't teach much computer stuff back then because PC's were so new. They did have a Data Processing class where they would feed code into an IBM mainframe via punch cards and then run their code. We also had a room of terminals that ran a version of BASIC that was written by one of my teachers. My first computer was the APF Imagination Machine. I was in my first year at DeVry so I knew very little about actual theory and troubleshooting.
When I first unboxed and plugged the computer in, it would run for a minute or so then shut down. Being the geek I was, I pinpointed a device in a TO-220 package that was loosely attached to a heatsink. My first thought was, "how is that going to work if it can't dissipate the heat? So, I snugged up the screw and I was in business! I'm thinking it was a regulator. Your videos bring back some fond memories. I had a couple C-64's, an Amiga 500 and an A1200 which I loved. I had the GVP sidecar for the A1200 with a 120MB drive in it! I also had the upgraded Agnus chip and the 2.0 Kickstart ROM.
I was hoping to see more Apple II on the channel, and despite technical difficulties, this did not disappoint. Thanks Adrian.
Love the Beagle Bros shirt! I'm envious. Retro-cool.
Hi Adrian. I really enjoyed this video, incredible stuff. It's really rare o see a computer from 1978 in such a mint condition. By the way you can boot the floppy from machine monitor by typing "6 ctrl-p enter" combination.
Man....I learn so much from your videos. In the more mechanical world...this tapping would be called "percussive maintenance". Glad to see it can apply elsewhere :) thank you for all you do :)
We use that phrase in IT, too! ;)
Either 6[ctrlP] to emulate PR#6, or 6{ctrlK] to emulate IN#6. Both of those should kick of a slot 6 boot. Also, C600G should have also worked.... I thought it was ctrlC to get from the monitor back to the BASIC prompt, but if ctrlB works, cool. You can also get to BASIC (usually, not always) by calling 3D0G. :)
I came here to add the C600G trick - it’s what we used on our //e when we (accidentally) got it into the monitor mode.
CTRL-B is a “cold start” into BASIC, while CTRL-C is a “warm start”. I don’t remember the exact differences off the top of my head, but a cold start might clear any program and reset the I/O vectors (so it might disconnect DOS if you were booted into it).
OBS is kinda complicated when it comes to capturing multiple sources then editing them out. Basically when I want to capture multiple full size 1080p sources I double the width resolution of the canvas then set the output to either be the same or scale it accordingly to the resolution I want. So basically 3840x1080 instead of 1920x1080. Then after I double it I put my two sources I want to capture next to each other in the full resolution they need. Bit rates might have to change due to that but I have not found it changes much. Now when you go to edit I recommend either using ffmpeg or handbrake to split the clips to be two different video files meaning cropping 1920px left for one then right for the other then putting it both clips in your video editing software so that the video editing software doesn’t have to handle cropping cause they can be weird about it sometimes.
I hope this helps and if you do have any questions I can help as much as I can
I spent many years using an Apple II, connected computer to small heaters, speakers, microphone and at one stage carried out diagnostics on a robotic motherboard for a robotics company. Interfacing with external chips was so easy. Towards the end was using a 5MB disc drive. I used to cut out a notch on the floppy discs so I could use both sides, others will remember this too I guess. A lovely computer. (Not sure if it was a plus)
Great educational video for vintage pros ❤ thank you sir 🫡
As far as fixing hot really chips go, back when I was working on some old Mod-Comp J1 and J2 machines, I found you could swap out some of the really hot current hog 74 and 74LS series chips with CMOS equivalents. The Mod_Comp machines used several rows of 74170 4x4 Register File chips. These chips ran really hot and were prone to frequent failure. Even the Mil Spec version of the 74170 chips failed. Swapping the TTL chips to CMOS greatly reduced the load on the power supply, made the machines run much cooler and made them more reliable. Changing current hogging magnetic core memory planes to solid state memory further reduced temps and increased reliability. I also found the same issues you found with the TI chip lead oxidation. The leads on some really old TI chips in those Mod-Comp machines would actually become so thin and brittle from oxidation that they would literally fall apart when you tried to remove them from the sockets! Heat and a high humidity environment would really do a number on them.
Note the MM5740 is not a microcontroller, it was a National Semiconductor dedicated Keyboard Encoder chip, which was pretty commonly used for parallel keyboards of the time. I seem to recall the MM5740AAF as most commonly used for ASCII encoded parallel keyboards. Note also, that these keyboard encoder chips were dual supply, requiring both 5V and a -12V supply. So you might also want to check both power supply voltages are good.
I still have our apple ii+ from the early 80's with 2 floppy drives. When we bought it, it was for educational use only and no games allowed but that changed over time as friends at school gave copies out and that's how we got them and mom and dad didn't mind but then did buy a few later.
So sad you can only give 1 thumbs up. These kind of videos deserve more!
You can click it twice
@@frugalprepper damn didnt know that, it also gets another color then
I decided early on that DeOxit'ing every socket was what I needed to resurrect my original Apple II that we bought in '79...really dodgy until I did that. Looking forward to your 2nd channel PS episode. You have to drill out the rivets in the older supply to get in and I found it didn't have a RIFA cap at all that I was ready to replace.
deoxit isn't magic, and it doesn't fix everything, but don't tell Adrian
@@raggededge82 You're absolutely right but it sure does go a long way towards solving many problems. I even dab 100% onto battery terminals which is most likely severe overkill but it makes me feel better! Too bad it doesn't cure "Dura-Leaks" these days. And yeah, mums the word! 😉
I like his videos, like this one, when he's not all sauced up. The difference is night and day.
4:50: If you compare those velcro-ish pads on your friend's machine with those shown on the cover of The Apple II Circuit Description book (cf. 15:02), you can see that the latter appear to be plastic-riveted, which suggests a design change at some point, meaning this also was an issue back then. Not that this solves the issue, and I'm not sure whether the rivets or glue came first, but I thought I'd point it out.
I mean, one way to solve the issue for sure would be to very carefully drill holes through both the pads and the case, and to use nuts and low-profile flat-head bolts and maybe washers to screw the pads down, but that mechanically sound solution would probably be unacceptable from an artefact preservation standpoint.
Today, the most significant difference between a rev1 and rev0 (with ventless lid) is resale price - a couple of hundred $$ versus a few-to-many thousand for rev0/ventless. :)
Dodgy Socket is also the name of my favorite band.
That "KRACKED BY MR. KRAC-MAN" is awesome. Computer world was lawless country back in the days 🙂
Hi Adrian, in monitor just use "c600g" (slot 6), another way type "6, then CTRL+K (or P)+Enter". Regard of the hot chip, as I remember when 1982 summer holiday, I need to put a fan to blow the RAM chips or hang up every 20 minutes, and I did not have original Apple ][+ but a clone.
It's a good thing the computer was working perfectly :) That made it easy to find all the bad connections and chips! Great video. Your patience with Apple computers amazes me!
Apple ][ case and motherboard Woz the most ingenious design I have ever come across in the 8-bit computing era especially when their was limited technology around to build and put together such equipment. Hands down the apple ][ was so neat on appearance.
Speaking of TI chips getting oxidised, I have a TI DS990 Model 1, and pretty much every single TI chip inside has black legs! All the 4116 RAM ICs needed to be cleaned up with a fiberglass pen. Silly machine still doesn't want to run correctly. Strangely, it will throw an error 'LOAD ERROR 22' when I turn it on, but if I turn it off, wait a few seconds and turn it on, it wont throw any errors, it'll just freeze. It'll be like that for a few hours, and then if I try it again, it will show the 'LOAD ERROR 22' error again. Also, I've not found any documentation which can tell me what the error number means.
Ahhh TI, so brilliantly amazing, but their execution always seems a bit off in places.
Really enjoyed this video! It is very interesting to see how Apple revised the Apple II over the models run.
It got me itching to muck around with a few old machines I have here. The TI is staring at me, but I have an iAPX 432 system that needs some attention.
It was a great video. The Apple II was the first computer I ever touched as a freshman in HS in 1980. Brought back a lot of memories not to mention all the troubleshooting on systems after electronics school for oxidation issues.
This is so fascinating thank you for the content! I am a tech in an industrial company your doing things here amazing!!! Keep it coming!
One of my first troubleshooting steps with digital equipment is to check the resistance readings of the voltage rails at the power connector and compare to a known good unit if available before the first power up. That way you can minimize the chance of releasing the smoke that’s sealed into the parts if it turns out to have a short in it.
This is the greatest retro computing channel.
I had an original rev. 0 Apple II. There was an article, I believe in Byte Magazine, showing the modifications necessary for 6-color hi-res graphics mode. I did that mod a couple of times; originally, I used a method that involved sticking wire-wrap sockets into the chip sockets in order to avoid cutting any traces on the motherboard. However, that eventually made the computer flaky (wire-wrap legs are much thicker than chip legs), so I later re-did the mod with directly soldered wires. I lived on that computer from middle school through high school.
excelente, saludos cordiales desde BUENOS AIRES (ARGENTINA)
@43:12 The machine language equivalent of PR#6 is C600G. C600 is the address of the Disk Controller ROM in Slot 6. 'G' is Go, as in run it. If, for example, you moved the disk controller to Slot 4, 5 or Slot 7 it would be C400, C500 or C700 respectively.
It was amazing to me to see how friendly and well thought out the design of the A2 for repairability. Now days you can't even open an Apple. (yes, I know you can, but you get the point.)
I loved these Apples when I was in school, and when my brother got a //c later. Coleco Adams are cool too...
I worked on these when they were new (8th grade) and they commonly had to be opened up and have all the chips reseated. Right away when I saw the monitor I was shouting at the screen "3D0G!!!" which is another way to get back to basic. It was the procedure before the autobot rooms came out - turn on -> 3D0G -> PR#6 and then you'd be booted.
Love the Beagle Bros shirt! They had the best ads with all sorts of little snippets of code.
Yea, Woz, my hero!
I'm into the apple content. Especially happy to see you doing diagnostics. Great video!
I came across your channel and found it quite interesting. I found it really interesting when I found this Apple ][ restoration video you put out.
I have no question for you, I'm just telling you my Apple story. I am the original owner of an Apple Integer machine that I bought in 1978-ish, it's in the original box in my closet, and I used it every day until about '95 when I made the jump to PC so I could play games Lol
The case and innards are in mint condition, except for in the early '80s when I opened the lid and a pencil fell in the crack and damaged a circuit (thank goodness it was turned off). My friend who owned a computer business (who sold me the computer, btw, his brother bought the first Apple ][ Computer in Canada (Woz signed the back of his at a computer show)) also fixed it, so thusly I have a resistor on the motherboard. It's been many years since I've opened it up, and when I did, it worked great (fantastic machine), but if I recall correctly there's an Apple 2+ card, a memory card, and a midi card, maybe a couple of others. Over the years I had hundreds (maybe thousands) of hours of fun with this computer. I'm not looking to sell it, I just thought you and your viewers might like a testimonial. Cheers!! 😬
Great video by the way!
Those case holders look like the 3M DUAL LOCK ipass transponder tape/pads. They come with adhesive that works on car windshields/temp swings/yanking on transponder.
I think typing "6 control-P" in the Apple ][ monitor should boot the disk in slot 6. Easier than switching to BASIC and doing "PR#6".
Yep, Control-P in the monitor is the equivalent of PR# in BASIC. And Control-K is like IN#. (The mnemonic is control-P sets where you Print, and control-K sets what Keyboard you use for input.) So you can use either 6 Control-P Return or 6 Control-K Return, since the standard Disk ][ controller will attempt to boot if you redirect either output or input to it. (And on a //e or later you can actually type 6 Up Arrow Return, since the up arrow maps to Control-K. But there's no up/down arrows on the ][ and ][+ keyboards.)
Ah nice! Thanks guys, I knew there was a shortcut, I just couldn't find it after some quick googling.
C600G and return will also work if you like typing extra stuff.
As a kid I had a lot of fun with Drol, too. Had it on my Atari 800.
I love the Apple ][ videos.
Lots of memories of those Apple II machines. Our local schools got them before they had an IT department. Math teacher wife was the first teacher in the county to push the use of computers in the classroom. She applied for and got a federal grant to buy some of the first computers used in our county schools. The first were TRS-80's immediately followed with the Apple II's and then Franklin's, (an Apple II knockoff). Back in those days she brought allot of those machines home for me to fix. I did find a couple of design issues with the Apple II that were made even worse in the Franklin's. I can't remember whether it was data or address lines that didn't use pull-up resistors but this caused intermittent crashes with one particular piece of education software. The Franklin motherboard was a carbon copy of the Apple II but it was physically a bit larger. As a result of the increased physical size, increased line length increased impedance and capacitive loading. This caused system timing issues. I seem to remember that one of the address or data lines ran all the way around the right side of the motherboard, down the bottom and back up the left side. For the most part the Apple II would run this particular piece of software with only occasional crashes. The Franklin's were another matter. I used a couple of 2.2k pull-up resistors and that fixed both machines. Another issue was the colors on another piece of educational software was flaky. Color rendition for that piece of software was poor on the Apple II and really awful on the Franklin. I can't remember the values or exactly where they were installed but a ceramic cap and a resistor installed somewhere around the, "Color Trim" variable cap fixed both the Franklin and the Apple II. This fix also improved colors on all other software.
That beep that the Apple II makes brings back memories. That was the first computer I had used and I was 5 at the time. Oh and there were certain programs that would only run when the disk controller card was indeed in slot 6.
Great fix. Don't worry about the video issues, we could still follow what you were doing. :)
you did a fantastic job adrian! nice apple 2! beautiful condition......
I had an Apple II+ as my first computer. This was interesting to see an earlier one. Looking forward to seeing if it can be fully whole with that original keyboard.
I have a couple of these. Sold a third one. Should have kept it. They keep going up in value
Still love it even with the issues!
1987 great build year!
I glued the cover catches back onto mine with hot glue. I originally tried double stick tape, which failed right away.
The Apple II Europlus was the first computer I ever used in 1980. The socketed chips were a mixed blessing we used to have to reseat the chips from time to time.
I pulled a C64 out of an e-waste container just half a year ago, and a Rockwell AIM-65 and a VIC-20 about 2 years ago. People still don't know what they're throwing away.
About 6 years ago I found two homebrew Apple ][+ bootlegs in the e-waste together with a Roland SH-2000 and a Jupiter-4 (yes!). I spoke to the owner and he actually knew what he was throwing away (and what it was worth on eBay) but didn't care about the four digit prices...
Apple did some pretty amazing things especially back in the early days. Great video!
Hey Adriane. I recall to boot the disk drive in monitor mode you would enter 6 Control P then press RETURN.
That's the first time I've seen the inside of an original Apple ][ since I was in 5th grade, in 1978. Ours had a Basic board, so it dropped right into Basic on power up. We were so happy when we got the disc controller and a floppy drive, because loading cassettes SUCKS.
Nice vid!! Thanks!!
Worked on an Apple II plus with Z80 card in college.
Adrian i have an Apple IIe love it. it sits in my office at work, it is a great talking point (im 50-51) with the 'younger folk' lol
@Adrian's Digital Basement I hope this information helps: Joe of Joe's Computer Museum is selling a replacement keyboard encoder chip for the older Apple II computers on his website. It has been tested on a few of the Apple II models, so why not give it a try? He has only 1 left as of this writing, though...
Adrian's basement looks so cozy
I seem to remember the drop fix, you dropped your PC onto a table to help the chips hopefully seat into the sockets. Gotta love it. Like the PC slap
I and probably other people find annoying there's light coming from top over you and theres a light t-shirt or shirt and the camera darkens your face.
Otherwise, another EXCELLENT video where you go through things and we love.
The Apple ][ Circuit Description book is a must have book for anyone working on Apple ][, and ][+ computers. I no longer have my Apple computers but I still have that book and many other of the Apple books for the machine. You can access the 256 byte "boot" code of a board in a slot at starting at address Cn00, where n is the slot number. To do the equivalent of PR#6 from the monitor you type C600G.
Came here to say the same thing. Crazy that I can still remember that code 40+ years later.
What a fun video to watch! You know your stuff man. So satisfying to see you get it all working. Well done!
18:30 The 6502 using its bus on only one half of each clock could simplify a video interface somewhat. But it also slowed the whole execution (clock speed) down, as the full memory access time was bound to just half a clock. In practice only about 60% of that time, or 30% of a full period, due to the design (and the nMOS transistors used).
So although the 6502 used about 2-3 times as few clocks as differently designed processors, it needed about six times as fast memory ICs compared to them, to reach the same "clock speed". (Other processors usually allowed two full clock periods for memory access.) That's one of the reasons why 6800 and 6502 computers were so slowly clocked. The 6502 line also lacked all sorts of 16-bit arithemetics, unlike its contemporaries. It needed a lot of bus traffic just to add or subtract two 16-bit numbers. So nothing was gained really.
Other simple computers typically used a WAIT signal to halt the CPU when video memory was accessed, which was a much smaller loss of performance than statically dedicating 50% of the bus to video access. More advanced computers used FIFO buffers and/or a wider bus to read out video data in the gaps always left by CPU execution.
I still have my Apple ][+ that i bought brand new. So new that it's an Apple ][ like this one, upgraded to the Plus by the computer store with ROMs from Apple. I even have the faux leather carrying bag/case for it!
Watching the vid will have to wait, I'm busy at the moment, but I hope to watch it and get inspired to check mine out and make sure it still works!
I grew up with the Apple ]['s in elementary school back in the late-80s and early-90s, and to this day I still kick myself in the pants for not checking in to see if/when they were being sent off to e-waste. But I did end up buying myself both an Apple ][ Plus and an Apple //GS just recently for a very reasonable price, along with a FloppyEmu, and all my elementary school memories came back... it was great.
I miss the old Apple Computer, Inc. days, when you can tinker and replace parts with ease. Modern Apple, Inc. feels like a whole other company.
@@nickfifteen Well, in many ways it _is_ a different company. But then the world and the computer market has changed, too. Computers tend to be more of an appliance now. Back then there was a lot more tinkering and expanding. That still happens, just in a different way.
Initializing the disk controller from the monitor is simple: C600G ...to initialize any other slot, just replace that 6 with the proper slot mumber.
Those keys look fantastic