My girlfriend keeps talking about wanting a new Macbook. It is incredibly tempting to buy her one of these for her birthday so I can film the reaction.
Hopefully Paul daniels' wonderful boardview software will help you fix it if anything ever goes wrong with it since there won't be any fanspin on these old girls. Way more reliable than these newer macbooks so it's probably a good investment
You should probably get her the Apple II, as at least when it breaks after a few years, she can give it you back and you will actually be able to repair it.
@@adriansdigitalbasement Why would you kill the poor thing that did no harm to you? I never understand why people squash bugs, it causes a mess, gets their hands dirty etc, why not put it out a window?
Adrian, your channel is big but it should be bigger. These kinds of videos are so great to watch, not only for entertainment, but to learn a lot of the things others had to do through experience without risking damaging anything in our own hands. I’m an electronics student, and these kinds of videos teach me a lot. Thank you, and keep doing these!
Great diagnosis, again! You're much like the automotive channels i like to follow, very methodological in finding the faults. It soothes the mind and saves old rare computers. You're a pro, not an amateur. Keep bangin', Adrian!
Tofu4679 Ah, a fellow South Main Auto fan. I agree, love the diagnostic mindset... and a careful visual inspection is useful for fixing both cars and computer hardware!
I think Adrian's rate of success in fixing things is even better than those folks who have the proper education and training in electronics....**cough** EEVBlog **cough**
Hey Adrian, prepare for a bump in subs care of Louis Rossmann. On another note, I’m in Portland too and love working on this vintage equipment! I have an original Macintosh on my bench for a recap right now in fact and did an SE30 a couple months ago (connector replacements).
The Apple IIc is probably the most beautiful 8-bit machine out there. It made my day to see this one rescued by Adrian to operational status rather than becoming purely a parts machine or worse ending up in the landfill.
I got a IIc with the same symptoms and I assumed it might be ram. This is the first video out there to really explain what's possibly happening. I'll be sure to comment again when I finally crack it open to check things out. It has to be said that your presentation style is awesome and universal for beginners and experts alike. Subbed!
Thanks to Adrian Black, 8-Bit Guy, and Retro Recipes, I have had great success repairing, upgrading and modifying all my Commodore and Apple computers. Thank for being so thorough and informative. Long live the Basement! 😁👍
29:24 That actually makes perfect sense if the version byte at 64447 was intended to be read as signed. The two's compliment of 255 for an 8-bit value would be -1. It may be that they were using negative version numbers to indicate pre-release versions the way that version numbers less than one are used today. So the version numbers ARE in proper order: -1,0,1,3,4.
A more likely explanation would be that that byte was simply left unprogrammed for the first ROM release, and then retroactively made into a version byte on further releases. Most ROM chips (and modern flash chips for that matter) have 0xFF as the default value for unprogrammed cells so this makes perfect sense.
Another option to the old gift card is to learn to play guitar. You'll always have picks around. Except when you actually need them to play the guitar. Another bonus if you go acoustic you'll usually be able to find one in the guitar. Love the videos!
This was my first computer. I picked it up at Goodwill. I was astonished at just how easy it was to disassemble. Good memories. The warmstart vs coldstart behavior you're describing actually explains a lot. Back in the day 13-year-old me without any manuals or the internet didn't know how to get into basic from the initial boot prompt. So my solution was to rapidly power cycle to get there. This was also my solution for a later II/GS I acquired.
That chunk out of the chip: I suspect what happened was the pin broke off at the edge of the package, and then the person chipped off the bottom to try to get to enough metal to re-solder the pin in place. That looks chipped off, not blown off or melted.
Cool little computer, even today. Love the matching little monitor and mouse that came with it. Great channel Adrian. Between you, 12voltvids, and joes classic games, I think I can learn to troubleshoot and fix almost anything. Thx!
Apparently the apple-dealer approved method of popping the case open is to remove the screws, set the machine back down the right way up, flip the handle/stand down so the machine is propped up at the back, lift it a few inches at the back and drop it! The handle will pop the top of the case off. Obviously this may or may not be a good idea with 36 year old plastic, but I tried it on my //c, and it worked! Great video, lots of detailed reasoning and very useful for my own troubleshooting. Thank you :)
@@Hagledesperado Really only important for benchmarks. The few hundred MHz (on average, sometimes Samsung VRAM can get a lot higher) difference between them doesn't really translate to much in games or most real-world applications. Micron vs Samsung was more important on the early 2080 ti models, where it seemed like Micron GDDR6 had a higher chance of failure, though Samsung VRAM cards still failed as well. Interestingly, there doesn't seem to be any real OC differences between them when it comes to GDDR6, it's 100% silicon lottery for both companies.
@@adriansdigitalbasement I can just see it now... Woz: "We need to make a great reliable new version of the Apple II" Jobs: "We'll take the cheap untested RAM. Just get them out the door, then we'll deny there's any widespread RAM problem"
I had grown up with 8bit and 16 bit machines... Then i moved on but looking at this videos is like time machine for me, because most of those machines had some troubles from time to time, and most of them were fixed by my father on spot in his shop. Great job!
I _like_ the up-facing sticky tape trick to check for contact, but you might want to do that with a small spacer under the tape so you know you have reliable clearance. Cases flex/expand/contract, after all.
Never owned these computers from the 80's other than the Atari 2600. But watching your troubleshooting videos makes me want to find one buried in a box at the local flea market & try to bring it back to life. Thanks for the troubleshooting vid!
Subscribed after watching your Compaq Deskpro vids. I'm a fella in his early 40's who started collecting computers in the late 90's when they were worth nothing. Started with the ones I lusted after as a kid and went from there. I gave away so many that I wish I still had but held onto my IIc along with many others. It's a labour of love and fixing them is a major part of the fun.
I picked up an Apple IIc from Craigslist recently. You've given me a good introduction and got me thinking about taking a crack at it. Congrats on all the new subscribers!
Hi Adrian ! I just discovered your channel and I love it ! I'll have to send you one of our finest French made Thomson MO5 or TO7 so you can check it... Thanks for passing on all this knowledge in such a clear and lively way. Keep up this great work !
@40:18 The person how soldered these chips on probably heated the chip up too much. So the plastic cracked and broke off, same of that shiny part probably too much heat from the soldering process too
I remember this memory persistence thing from elementary school. Most students would not use apple-ctrl-reset and would power cycle quickly to change programs, and think they broke the computer. Eventually everyone learned to count to 3 before turning the power back on.
Might not just be memory perisistence, but also the power supply capacitors that need time to discharge, so the MMU and the rest of the machine will definitely keep running for a few seconds until the voltage becomes low enough for the chips to shut down. Most 5V logic chips will run OK at voltages down to 3,3V, but when it goes lower, data will get corrupted.
When you have to remove THT DIL chips (or some SMT packages as well) from a board, if you know the chip is bad or you have a replacement, then I find it easier to just snip off the legs close to the chip body using a pair of micro side cutters. Then the chip will just drop off, and it is much easier to de-solder the legs one at a time (like you did at 23:53 in this video) and clean out the hole (or SMT pad). This minimises the risk of damaging the PCB pad and hole plating. I have also used this technique to remove multi-way connectors, although it can be awkward depending on the connector type.
Oh yeah. I remember always being taught as a kid when power-cycling my computer (starting on my CoCo2) to always leave the machine off for 10 seconds before turning it back on. My Enhanced IIe will hold memory like that as well if I do too quick a power cycle. GREAT JOB rescuing another vintage machine and saving it from the trash pile! I hope to add a IIc and a IIgs to my collection ONE of these days.
Just mentioning Louis Rossmann got a like from me, LOL! Although I never opened a IIc, I do have fond memories of them during my high school days. And kudos for re-using the TRS-80 Model III badge/label on your monitor!
Great video, sir! What a nice blast from the past! I was about 22 yrs-old when these came out and colleges and universities rushed to install them. I've forgotten most of the commands but hearing about PEEK and POKE made me smile and nod. I came here via a shoutout from Louis Rossmann's channel, by the way. One new sub for 2020! 👍
Adrian, this was a excellent video and I enjoyed watching the way you went about your diagnosis process and repair. Thank you very much for the time in putting this together. Its truly a great job.
Really great fault find thanks for sharing. I normally restore vintage radios but thinking of trying a vintage computer so I’m bulk watching all your videos to see how you fault find. Thanks Regards Chris
I've always been told, since the 80's, to wait 10 to 15 seconds before powering back on a computer. That power cycling too quickly could damage components. Or at the very least send a power surge through the computer causing problems. Great video as always! I have 4 IIc's that have a similar problem. I'll have to check those memory chips now. Thanks for the video!
This was nice to see. While I never owned an Apple, we had Apple II+s in and then Apple IIes in high school back in the dusty past. These were mostly used in "Computer Science" classes where we learned BASIC and Turbo Pascal programming (the "E"s had CP/M cards with Z80A processors installed). Interesting machines. All the 8-bit micros had personality, unlike today's rubbish. A world that runs on '80s technology would be a heaven. It was the best of times.
There’s an attack that can be performed against a machine that takes advantage of that if you have physical access - you take a can of cold spray (basically canned “air”, but setup to spray liquid - when it comes out it freezes anything it hits) and spray the RAM; then quickly move the DIMMs to a purpose-built machine to dump the contents to disk for forensic analysis. The cold spray increases the amount of time you have to work - sometimes up to 15 min, if you keep spraying it. It’s particularly useful for recovering encryption keys from a machine that you don’t have the password to; but is still running.
knockeddownanotch - Presumably... I heard about it on the Security Now podcast a few years ago; I *think* it was a presentation at one of the security/hacking conferences???
@@darkwinter6028 I've tried this "cold boot attack" some 10 years ago in front of a small audience. I had two laptops with similar ram specs. I opened some files on the target machine and then turned it off. I sprayed the RAM with upside down canned air and then moved the chips to the other laptop. This laptop booted into a very small image that would extract the memory to a disk file (so yes some of the ram was overwritten). I think I used hex editors and maybe Volatility (??) and browsed the dump. I think I was even able to get a truecrypt key and cookie values.
I'm a new subscriber currently working on an Apple IIc similar to what I used in college. I like the detail you go into on this video, which should help me along the way to restoring my very worn out IIc. I will eventually get around to going through all of your videos in the near future. Keep up the great content.
That keyboard has the best-feeling switches I've ever used. (We had a lab full of these in my elementary school, most of them had the crunchy Alps keyboards.)
The first computer we owned when I was a kid was a //c. I remember that the manual said if one wants to power cycle, wait 15 seconds in between off and on.
These are the computers we had when I was in Elementary school. Have tons of good memories playing games on these in kindergarten, first, second, third grade or so. After then, I think our school upgraded to Macintosh computers, but those were only in the school library. Sadly, teachers would never schedule our class to go. I remember using those Macintosh computers two or three times ever. The Apple //c computers were in every classroom, at least 4 of them.
I actually have one of these myself! Though it doesn't work unfortunately. I have no idea about anything when it comes to working on old machines like this, but your videos have given me quite a bit of insight. Thanks!
I haven't even seen it through and already liked it! I have some IIc here - some I'll sell, some will be with me. I have the UNIDISK Air by Nishida Radio that is mavelous - it works as a primary disk, can be set to work as a secondary disk, is hidden within the machine and works with a ssd/wifi module. Unfortunately Nishida is not well - here I leave my best wishes for his health. Adrian, thanks for the video! You helped me a lot!!!
Huh, I had no idea about that warm reset thing. I recently picked up a IIc, and I thought it was weird that I had to wait like 30 seconds to simply power cycle the machine. Didn't know about the apple+control+reset thing, that'll be very helpful as I work through getting it serviced and learning how to use it! Thanks for sharing that info!
It was very interesting to see your troubleshooting of the first Apple I ever purchased. As my friends say often, I've had so many apple products, I bleed in 6 colours! Cheers from Canada.
Hi Adrian I rarely comment on your videos even if I watch all of them, I just wanted to say I'm proud of the work you're doing and for the MASSIVE improvement of the audio/video quality. Keep up the great work.
I once told a old dos computer if it didn't behave we were taking it out to the back 40 and putting it down humanely. It stopped crashing for over a year after that.
@@JB-ym4up I used to threaten them with defenestration and that I would time that so it would land in front of one of the busses that drove past every few minutes. It was surprisingly effective.
I think you are right about the warm start not clearing RAM quickly enough. I used to notice this with noughties Windows PCs when I started increasing the amount of RAM on an older motherboard as RAM became cheaper. I also probably didn't buy the best chips. Now, as a matter of course, I always do a full restart if I want to reset the machine. Nice job BTW.
Hello fellow Canuck! I subscribed during one of those C64 videos you spoke of. And as of today (or this comment), I noticed you now have "56.6K subscribers"... I feel like finding an old US Robotics modem for some reason... XD Awesome video! This is like a thrilling TV Hospital Drama. So much fun watching the diagnoses and fixing procedures.
Sorry. Late post. But I have really been enjoying watching the troubleshooting vids. Thank you! I've seen ICs damaged like that from an internal malfunction. Static discharge or electrical transients can cause the gate logic on those parts to short out and self-destruct. The package literally pops and cracks just like that. That blackened flakey area was likely also overheated internally from a short that may have also heated the pin and the PCB, which could have caused the via to release from the PCB substrate. The shorts on the part also cause havoc on other parts connected to the signals net... Now I wish I hadn't given up all my HW over the years. I miss my SuperPet 9000 the most. Cheers.
I got my Apple //c for $1 at a thrift store back in '99. This was before most people were comfortable with ebay and just donated stuff to thrift stores, those were the days! I have the 3rd revision with a memory expansion port. I believe the last 2 models had this, it's located in the lower right side of the main board. It's in a spot where RAM chips would normally be but the last couple models condensed the RAM chips to 4x 32k chips, I could be wrong though. I truly love this computer and hope to never sell it. Even down the road if it becomes more valuable I still won't sell it. It marks the first time in my career of collecting that I got an Apple //. I also have a couple //gs, one with a 1MB expansion slot. I'm currently learning how to program the 6502 in assembly so I can make some cool (on uncool lol) games. Awesome video!
Nice, I haven't ever seen that later revision with the RAM expansion. You may want to check out the ROM 4X for it -- which is a modified ROM with a ton of cool features for that particular IIc. (But works on all other IIc versions too.)
I wouldn't mind getting an Apple ][c sometime. Neat little things. I just wish I still had my Apple ][ floppies. You have high persistence slow RAM. I've seen this problem even on an Atari 800XL.
Adrian.... Row Address Strobe and Column address Strobe... The dynamic DRAM chip bit data is accessed as a row and column address of the bits. They are arranged in a square. 8^2 (256) ROWS x 8^2 (256)columns for 65536 individually addressable bits. If I remember correctly, the refresh is done by a device accessing the RAS and CAS sequentially for all the cells to recharge the capacitance in each bit cell before it drains/leaks out. RAS and CAS are used to access the bit data in a READ, WRITE, or REFRESH operation..
Nice work finding the fault. When the chip is to be discarded and the board shows signs of previous work on the chip, I cut the legs off first before desoldering so that individual pins can be pulled out with a normal iron with little force to protect the board as much as possible from lifting pads. If the board repair really looks bad, I lower the iron temp and use chipquik.
I've used the piggyback method to diagnose and repair a ISA extended memory card, 5MB of 64k chips, all soldered on both the base board and on a daughterboard. Took a couple of days to isolate the bad chip but the satisfaction was great when I fixed it.
Louis rossman actually posted a video recommending to watch this video and I actually enjoyed watching it even though I don't understand much electronics repair yet.
Great video and very helpful to me. I have an Apple //c with the same motherboard and similar problems. I can get back to diagnosing it now. And my Apple //e has the same power-on reset problem. I never made the connection that the problem was just the $3F4 flag and memory persistence and not something more serious.
And another success! I don't have one myself but I'd like to pick one up someday (the IIc was one of the first computers I ever used) - maybe I'll actually try to make it to the Commodore Club meeting next month and see if someone has one to sell/trade.
Why does the refresh cause activity on the ram data pins that he is reading with the oscilloscope? That was not intuitive, and I was confused by the transition from talking about the ram refresh to suddenly looking for (AND FINDING) pulses on the data pins. P.S. This is the only channel where the repair videos leave me a little bit smarter. So grateful...
I love your videos, you explain everything in a easy way to understand, congratulations fou this great job. I would like to know your basement lab it shoulde be a wonder place.
This was a very instructive video! Great fun! BTW the film "2010" features Heywood Floyd (Roy Schieder) on the beach hacking on an Apple ][c with the rare LCD screen. I would be hunting for one of those!
When I first started on computers I was told about the power off for 30 sec or more rule. In fact my Apple II plus has that issue. If I power cycle it to fast. stuff get stuck in memory. Nice apple IIc. Great Channel.
The floating point BASIC autostart ROMs were so new when I bought my Apple ][+ that the case didn't say "plus" and the ROMs were installed at the store. It definitely had the warm start versus cold start issue you demonstrated. It wasn't considered as a problem, just normal operation! 😉
@@adriansdigitalbasement Do you mean the one sitting in my basement? I haven't tried to power it on in years. I need to dig it out; it's in a fake leather carrying bag/case with handles. It has 48K of RAM, never had Apple 5.25-inch floppy drives, Franklin Ace ones instead! [ Update: I dug it out, did not try to power it on yet. Yes, it's in the soft carry bag. The cover says "Apple ][", no plus, and it has the white square power light in the lower left corner of the keyboard. I'll look for Rev numbers on the mainboarď; not sure how to tell the different updated production versions. ]
Really enjoyed this video Adrian. Please do more Apple II videos. I have a IIE enhanced which has no beep or image at startup. I’ll take a look at those memory chips.
My girlfriend keeps talking about wanting a new Macbook. It is incredibly tempting to buy her one of these for her birthday so I can film the reaction.
Hopefully Paul daniels' wonderful boardview software will help you fix it if anything ever goes wrong with it since there won't be any fanspin on these old girls. Way more reliable than these newer macbooks so it's probably a good investment
At least the keyboard actually works in this Apple product
You should probably get her the Apple II, as at least when it breaks after a few years, she can give it you back and you will actually be able to repair it.
Louis get her one of these
th-cam.com/video/r9azAdhqo5A/w-d-xo.html
If it was any nicer...
One of the computer's bugs escaped at 6:12. :D
I see whatcha did there...
@@adriansdigitalbasement Why did you kill it? You could have just put it outside :(
I was about to comment this.
@@adriansdigitalbasement Why would you kill the poor thing that did no harm to you? I never understand why people squash bugs, it causes a mess, gets their hands dirty etc, why not put it out a window?
Sorry but I have to do this: "Buuuuuuuuuuugs!!!!!" dakkadakkadakka
Adrian, your channel is big but it should be bigger. These kinds of videos are so great to watch, not only for entertainment, but to learn a lot of the things others had to do through experience without risking damaging anything in our own hands. I’m an electronics student, and these kinds of videos teach me a lot. Thank you, and keep doing these!
Great diagnosis, again! You're much like the automotive channels i like to follow, very methodological in finding the faults. It soothes the mind and saves old rare computers. You're a pro, not an amateur. Keep bangin', Adrian!
Well there's your problem lady!
Tofu4679 Ah, a fellow South Main Auto fan.
I agree, love the diagnostic mindset... and a careful visual inspection is useful for fixing both cars and computer hardware!
I think Adrian's rate of success in fixing things is even better than those folks who have the proper education and training in electronics....**cough** EEVBlog **cough**
Hey Adrian, prepare for a bump in subs care of Louis Rossmann. On another note, I’m in Portland too and love working on this vintage equipment! I have an original Macintosh on my bench for a recap right now in fact and did an SE30 a couple months ago (connector replacements).
Whenever someone likes this comment I get a notification saying "Hey, Adrian someone..." and it is slowly driving me insane.
@@eden12340 +1 Like 🤣
MoosesValley For shame
Sorry.
The Apple IIc is probably the most beautiful 8-bit machine out there. It made my day to see this one rescued by Adrian to operational status rather than becoming purely a parts machine or worse ending up in the landfill.
I got a IIc with the same symptoms and I assumed it might be ram. This is the first video out there to really explain what's possibly happening. I'll be sure to comment again when I finally crack it open to check things out. It has to be said that your presentation style is awesome and universal for beginners and experts alike. Subbed!
I love the fact you care about the little things like rusty screws and de-yellowing the plastic. You do things properly, love it :-)
Thanks to Adrian Black, 8-Bit Guy, and Retro Recipes, I have had great success repairing, upgrading and modifying all my Commodore and Apple computers. Thank for being so thorough and informative. Long live the Basement! 😁👍
29:24 That actually makes perfect sense if the version byte at 64447 was intended to be read as signed. The two's compliment of 255 for an 8-bit value would be -1.
It may be that they were using negative version numbers to indicate pre-release versions the way that version numbers less than one are used today.
So the version numbers ARE in proper order: -1,0,1,3,4.
A more likely explanation would be that that byte was simply left unprogrammed for the first ROM release, and then retroactively made into a version byte on further releases. Most ROM chips (and modern flash chips for that matter) have 0xFF as the default value for unprogrammed cells so this makes perfect sense.
Another option to the old gift card is to learn to play guitar. You'll always have picks around. Except when you actually need them to play the guitar. Another bonus if you go acoustic you'll usually be able to find one in the guitar. Love the videos!
Haha yeah you pretty much only find your picks when you're not using them
I recently bought a toolkit that had a spudger in it that was basically just a guitar pick.
This was my first computer. I picked it up at Goodwill. I was astonished at just how easy it was to disassemble. Good memories. The warmstart vs coldstart behavior you're describing actually explains a lot. Back in the day 13-year-old me without any manuals or the internet didn't know how to get into basic from the initial boot prompt. So my solution was to rapidly power cycle to get there. This was also my solution for a later II/GS I acquired.
That chunk out of the chip: I suspect what happened was the pin broke off at the edge of the package, and then the person chipped off the bottom to try to get to enough metal to re-solder the pin in place. That looks chipped off, not blown off or melted.
My thoughts also.
Agreed. I remember doing some work like this when I was first learning to solder. It never went well.
Exactly what I was thinking, l know RAM used to be expensive but that is going a bit far!
yep, I'll bet that chip was $$$ back in the day, simple fix and probably worked fine for years
That could be true... YUK!!
Cool little computer, even today. Love the matching little monitor and mouse that came with it. Great channel Adrian. Between you, 12voltvids, and joes classic games, I think I can learn to troubleshoot and fix almost anything. Thx!
Apparently the apple-dealer approved method of popping the case open is to remove the screws, set the machine back down the right way up, flip the handle/stand down so the machine is propped up at the back, lift it a few inches at the back and drop it! The handle will pop the top of the case off. Obviously this may or may not be a good idea with 36 year old plastic, but I tried it on my //c, and it worked! Great video, lots of detailed reasoning and very useful for my own troubleshooting. Thank you :)
The MT branding on the RAM chips is the old Micron Technology logo, it's the same company that still makes computer RAM and SSD's today
If you want to overclock a GTX 1070 graphics card, you will probably want a card with Samsung RAM instead of Micron RAM though.
@@adriansdigitalbasement Contact them and demand warranty replacements :)
I guess Microm got better once they stopped making their chips in the USA... as is clearly stamped on the chip
@@Hagledesperado Really only important for benchmarks. The few hundred MHz (on average, sometimes Samsung VRAM can get a lot higher) difference between them doesn't really translate to much in games or most real-world applications. Micron vs Samsung was more important on the early 2080 ti models, where it seemed like Micron GDDR6 had a higher chance of failure, though Samsung VRAM cards still failed as well. Interestingly, there doesn't seem to be any real OC differences between them when it comes to GDDR6, it's 100% silicon lottery for both companies.
@@adriansdigitalbasement I can just see it now...
Woz: "We need to make a great reliable new version of the Apple II"
Jobs: "We'll take the cheap untested RAM. Just get them out the door, then we'll deny there's any widespread RAM problem"
I do not have an apple of any kind or commodore but I like to watch your videos. I learn a lot. Thank you.
I had grown up with 8bit and 16 bit machines...
Then i moved on but looking at this videos is like time machine for me, because most of those machines had some troubles from time to time, and most of them were fixed by my father on spot in his shop.
Great job!
Louis Rossman sent me here, he was right. Great video!
I _like_ the up-facing sticky tape trick to check for contact, but you might want to do that with a small spacer under the tape so you know you have reliable clearance. Cases flex/expand/contract, after all.
Never owned these computers from the 80's other than the Atari 2600. But watching your troubleshooting videos makes me want to find one buried in a box at the local flea market & try to bring it back to life. Thanks for the troubleshooting vid!
Subscribed after watching your Compaq Deskpro vids. I'm a fella in his early 40's who started collecting computers in the late 90's when they were worth nothing. Started with the ones I lusted after as a kid and went from there. I gave away so many that I wish I still had but held onto my IIc along with many others. It's a labour of love and fixing them is a major part of the fun.
22:16 I recognize this track from Means Morning News and keep hearing it everywhere, so *thank* you for leaving song titles in the description!
This the proper approach to troubleshoot a non working vintage computer. Loved the video and enjoyed your method.
I picked up an Apple IIc from Craigslist recently. You've given me a good introduction and got me thinking about taking a crack at it. Congrats on all the new subscribers!
Hi Adrian ! I just discovered your channel and I love it ! I'll have to send you one of our finest French made Thomson MO5 or TO7 so you can check it...
Thanks for passing on all this knowledge in such a clear and lively way. Keep up this great work !
I was sent here by Louis Rossmann. I subbed immediately. It’s like a PG version of Louis. Lol.
haha so was I lol!!
ohh I cant remember now, I think it was when he was looking at that new shop with the property agent and measuring up.
@40:18 The person how soldered these chips on probably heated the chip up too much. So the plastic cracked and broke off, same of that shiny part probably too much heat from the soldering process too
That shiny stuff is most likely just some flux residue
I remember this memory persistence thing from elementary school. Most students would not use apple-ctrl-reset and would power cycle quickly to change programs, and think they broke the computer. Eventually everyone learned to count to 3 before turning the power back on.
Might not just be memory perisistence, but also the power supply capacitors that need time to discharge, so the MMU and the rest of the machine will definitely keep running for a few seconds until the voltage becomes low enough for the chips to shut down. Most 5V logic chips will run OK at voltages down to 3,3V, but when it goes lower, data will get corrupted.
@@Stoney3K Maybe this is why IBM came up with the "power good" signal from the power supply.
I seriously sit here and watch your videos for hours! Thanks for the great content, Adrian!
Wow, this just taught me why I would see "ghosts" of previous sessions when I would flip the power on my school's IIC quickly!!!!
When you have to remove THT DIL chips (or some SMT packages as well) from a board, if you know the chip is bad or you have a replacement, then I find it easier to just snip off the legs close to the chip body using a pair of micro side cutters. Then the chip will just drop off, and it is much easier to de-solder the legs one at a time (like you did at 23:53 in this video) and clean out the hole (or SMT pad). This minimises the risk of damaging the PCB pad and hole plating. I have also used this technique to remove multi-way connectors, although it can be awkward depending on the connector type.
the apple IIc was the first computer i ever used, i remember playing oregon trail on it all the time when i was little.
Nice to see new material on retro computing that is this well produced! Cheers from Romania!
Oh yeah. I remember always being taught as a kid when power-cycling my computer (starting on my CoCo2) to always leave the machine off for 10 seconds before turning it back on. My Enhanced IIe will hold memory like that as well if I do too quick a power cycle. GREAT JOB rescuing another vintage machine and saving it from the trash pile! I hope to add a IIc and a IIgs to my collection ONE of these days.
Just mentioning Louis Rossmann got a like from me, LOL! Although I never opened a IIc, I do have fond memories of them during my high school days. And kudos for re-using the TRS-80 Model III badge/label on your monitor!
Great video, sir! What a nice blast from the past! I was about 22 yrs-old when these came out and colleges and universities rushed to install them. I've forgotten most of the commands but hearing about PEEK and POKE made me smile and nod. I came here via a shoutout from Louis Rossmann's channel, by the way. One new sub for 2020! 👍
Adrian, this was a excellent video and I enjoyed watching the way you went about your diagnosis process and repair. Thank you very much for the time in putting this together. Its truly a great job.
Really great fault find thanks for sharing. I normally restore vintage radios but thinking of trying a vintage computer so I’m bulk watching all your videos to see how you fault find. Thanks Regards Chris
I've always been told, since the 80's, to wait 10 to 15 seconds before powering back on a computer. That power cycling too quickly could damage components. Or at the very least send a power surge through the computer causing problems.
Great video as always! I have 4 IIc's that have a similar problem. I'll have to check those memory chips now. Thanks for the video!
This was nice to see. While I never owned an Apple, we had Apple II+s in and then Apple IIes in high school back in the dusty past. These were mostly used in "Computer Science" classes where we learned BASIC and Turbo Pascal programming (the "E"s had CP/M cards with Z80A processors installed). Interesting machines. All the 8-bit micros had personality, unlike today's rubbish. A world that runs on '80s technology would be a heaven. It was the best of times.
whoah, congrats! It's such a rewarding thing to see a great successful repair on an old computer.
Some RAM chips take a while to decay, sometimes up to minutes
There’s an attack that can be performed against a machine that takes advantage of that if you have physical access - you take a can of cold spray (basically canned “air”, but setup to spray liquid - when it comes out it freezes anything it hits) and spray the RAM; then quickly move the DIMMs to a purpose-built machine to dump the contents to disk for forensic analysis. The cold spray increases the amount of time you have to work - sometimes up to 15 min, if you keep spraying it. It’s particularly useful for recovering encryption keys from a machine that you don’t have the password to; but is still running.
@@darkwinter6028 neat. any video demo of this?
knockeddownanotch - Presumably... I heard about it on the Security Now podcast a few years ago; I *think* it was a presentation at one of the security/hacking conferences???
This machine's factory chips probably had a faster decay rate. The replacements may have been designed for longer times between refreshes.
@@darkwinter6028 I've tried this "cold boot attack" some 10 years ago in front of a small audience. I had two laptops with similar ram specs. I opened some files on the target machine and then turned it off. I sprayed the RAM with upside down canned air and then moved the chips to the other laptop. This laptop booted into a very small image that would extract the memory to a disk file (so yes some of the ram was overwritten). I think I used hex editors and maybe Volatility (??) and browsed the dump. I think I was even able to get a truecrypt key and cookie values.
i wish i had your patience, i realy love watching you solve the problems with these things its just great
2:00: Somebody PLEASE share the link of that video where someone couldn't open the floppy drive. I MUST see that.
I'm a new subscriber currently working on an Apple IIc similar to what I used in college. I like the detail you go into on this video, which should help me along the way to restoring my very worn out IIc. I will eventually get around to going through all of your videos in the near future. Keep up the great content.
That keyboard has the best-feeling switches I've ever used. (We had a lab full of these in my elementary school, most of them had the crunchy Alps keyboards.)
The first computer we owned when I was a kid was a //c. I remember that the manual said if one wants to power cycle, wait 15 seconds in between off and on.
Found your channel when I needed to fix my LCD and have subscribed. I enjoy your approach and the journey on these projects.
These are the computers we had when I was in Elementary school. Have tons of good memories playing games on these in kindergarten, first, second, third grade or so. After then, I think our school upgraded to Macintosh computers, but those were only in the school library. Sadly, teachers would never schedule our class to go. I remember using those Macintosh computers two or three times ever. The Apple //c computers were in every classroom, at least 4 of them.
Great video Adrian! That second Memory chip was damaged by someone using too much heat to solder it in. That heat also lifted the pads on the MB.
I actually have one of these myself! Though it doesn't work unfortunately. I have no idea about anything when it comes to working on old machines like this, but your videos have given me quite a bit of insight. Thanks!
I haven't even seen it through and already liked it! I have some IIc here - some I'll sell, some will be with me. I have the UNIDISK Air by Nishida Radio that is mavelous - it works as a primary disk, can be set to work as a secondary disk, is hidden within the machine and works with a ssd/wifi module. Unfortunately Nishida is not well - here I leave my best wishes for his health.
Adrian, thanks for the video! You helped me a lot!!!
Ive never watched a video that long n interesting, thabks for the content, Louis sent us here !
Huh, I had no idea about that warm reset thing. I recently picked up a IIc, and I thought it was weird that I had to wait like 30 seconds to simply power cycle the machine. Didn't know about the apple+control+reset thing, that'll be very helpful as I work through getting it serviced and learning how to use it! Thanks for sharing that info!
It was very interesting to see your troubleshooting of the first Apple I ever purchased. As my friends say often, I've had so many apple products, I bleed in 6 colours! Cheers from Canada.
Watching these is inspiring. They almost make me think I could do this myself, but I don't have an oscilloscope.
Hi Adrian
I rarely comment on your videos even if I watch all of them, I just wanted to say I'm proud of the work you're doing and for the MASSIVE improvement of the audio/video quality.
Keep up the great work.
I miss my old 8-bits from time to time, thanks for the video it was fun watching you work on it.
Louis Rossmann sent me here.
I usually just stare at them, and they fix themselves out of fear.
I love to introduce you to my wife. :)
only chuck norris can do that! somtimes he force it to function corectly again with a roundhouse kick! :-)
I once told a old dos computer if it didn't behave we were taking it out to the back 40 and putting it down humanely. It stopped crashing for over a year after that.
@@JB-ym4up I used to threaten them with defenestration and that I would time that so it would land in front of one of the busses that drove past every few minutes. It was surprisingly effective.
I have a small tub of thermite, solely to intimidate electronics into working.
I think you are right about the warm start not clearing RAM quickly enough. I used to notice this with noughties Windows PCs when I started increasing the amount of RAM on an older motherboard as RAM became cheaper. I also probably didn't buy the best chips. Now, as a matter of course, I always do a full restart if I want to reset the machine. Nice job BTW.
Hello fellow Canuck!
I subscribed during one of those C64 videos you spoke of. And as of today (or this comment), I noticed you now have "56.6K subscribers"... I feel like finding an old US Robotics modem for some reason... XD Awesome video! This is like a thrilling TV Hospital Drama. So much fun watching the diagnoses and fixing procedures.
Thank you for appeasing people like me by covering that ROM window. Great video!
Sorry. Late post. But I have really been enjoying watching the troubleshooting vids. Thank you!
I've seen ICs damaged like that from an internal malfunction. Static discharge or electrical transients can cause the gate logic on those parts to short out and self-destruct. The package literally pops and cracks just like that. That blackened flakey area was likely also overheated internally from a short that may have also heated the pin and the PCB, which could have caused the via to release from the PCB substrate. The shorts on the part also cause havoc on other parts connected to the signals net...
Now I wish I hadn't given up all my HW over the years. I miss my SuperPet 9000 the most.
Cheers.
I got my Apple //c for $1 at a thrift store back in '99. This was before most people were comfortable with ebay and just donated stuff to thrift stores, those were the days! I have the 3rd revision with a memory expansion port. I believe the last 2 models had this, it's located in the lower right side of the main board. It's in a spot where RAM chips would normally be but the last couple models condensed the RAM chips to 4x 32k chips, I could be wrong though. I truly love this computer and hope to never sell it. Even down the road if it becomes more valuable I still won't sell it. It marks the first time in my career of collecting that I got an Apple //. I also have a couple //gs, one with a 1MB expansion slot. I'm currently learning how to program the 6502 in assembly so I can make some cool (on uncool lol) games. Awesome video!
Nice, I haven't ever seen that later revision with the RAM expansion. You may want to check out the ROM 4X for it -- which is a modified ROM with a ton of cool features for that particular IIc. (But works on all other IIc versions too.)
Louis Rossmann just gave you an amazing shout out for you awesome work!
Love the scene in "2010" Where Roy Scheider uses one of these at the beach with that rare LCD snap on screen.
This video was excellent! Keep up the good work, Adrian. I'm going to go watch the C64 one, now.
I wouldn't mind getting an Apple ][c sometime. Neat little things. I just wish I still had my Apple ][ floppies.
You have high persistence slow RAM. I've seen this problem even on an Atari 800XL.
Very well repair, continued efforts for healthing the Apple 2c computer.
Congratulations.
Keep up the the good work.
I really enjoy observing your logic in your troubleshooting. Happy New Year 2020!
Wozniak probably could have know what chip and pin was wrong by looking at the screen 😂😂🤯 good job btw!
Adrian.... Row Address Strobe and Column address Strobe... The dynamic DRAM chip bit data is accessed as a row and column address of the bits. They are arranged in a square. 8^2 (256) ROWS x 8^2 (256)columns for 65536 individually addressable bits. If I remember correctly, the refresh is done by a device accessing the RAS and CAS sequentially for all the cells to recharge the capacitance in each bit cell before it drains/leaks out. RAS and CAS are used to access the bit data in a READ, WRITE, or REFRESH operation..
Nice work finding the fault. When the chip is to be discarded and the board shows signs of previous work on the chip, I cut the legs off first before desoldering so that individual pins can be pulled out with a normal iron with little force to protect the board as much as possible from lifting pads. If the board repair really looks bad, I lower the iron temp and use chipquik.
@@adriansdigitalbasement If it's a choice between loosing an LS part or bad pads, I'll loose the LS!
Louis sent me here, such refreshing cool content!
I've used the piggyback method to diagnose and repair a ISA extended memory card, 5MB of 64k chips, all soldered on both the base board and on a daughterboard. Took a couple of days to isolate the bad chip but the satisfaction was great when I fixed it.
50k subs! Ive been watching for years, glad your gaining subs, quality content
An Apple IIc at a Commodore Club? Such heresy! ;)
Great job as always! :)
I love your mention of Louis Rossmann as I just got done watching his new video :D I'm enjoying your channel, and subscribed!
I was more of a Commodore guy back in those days, so this is full of great info. Good job, and keep making the great videos!
Louis rossman actually posted a video recommending to watch this video and I actually enjoyed watching it even though I don't understand much electronics repair yet.
Great video. Very clear fault finding process with interesting info on the RAM data persistence problem.
Louis Rossmann sent us to check out this video and I enjoyed it, thanks!
Great video and very helpful to me. I have an Apple //c with the same motherboard and similar problems. I can get back to diagnosing it now. And my Apple //e has the same power-on reset problem. I never made the connection that the problem was just the $3F4 flag and memory persistence and not something more serious.
Good job! Awesome video, now I want to go take mine apart and fix the 'D' key.........
Really enjoyed the technical depth in this video!!
And another success! I don't have one myself but I'd like to pick one up someday (the IIc was one of the first computers I ever used) - maybe I'll actually try to make it to the Commodore Club meeting next month and see if someone has one to sell/trade.
I really like the detail you put into your videos. Very informative.
Loving the music Adrian. Totally captures the appropriate vibe of your content!!!
Why does the refresh cause activity on the ram data pins that he is reading with the oscilloscope? That was not intuitive, and I was confused by the transition from talking about the ram refresh to suddenly looking for (AND FINDING) pulses on the data pins.
P.S. This is the only channel where the repair videos leave me a little bit smarter. So grateful...
I love your videos, you explain everything in a easy way to understand, congratulations fou this great job. I would like to know your basement lab it shoulde be a wonder place.
This was a very instructive video! Great fun! BTW the film "2010" features Heywood Floyd (Roy Schieder) on the beach hacking on an Apple ][c with the rare LCD screen. I would be hunting for one of those!
When I first started on computers I was told about the power off for 30 sec or more rule. In fact my Apple II plus has that issue. If I power cycle it to fast. stuff get stuck in memory. Nice apple IIc. Great Channel.
They're not bad RAM chips, they're just always MT. :D
I'll leave now.
Well... I just want to say you: Thank you. I am learning a lot with your videos.
The floating point BASIC autostart ROMs were so new when I bought my Apple ][+ that the case didn't say "plus" and the ROMs were installed at the store. It definitely had the warm start versus cold start issue you demonstrated. It wasn't considered as a problem, just normal operation! 😉
@@adriansdigitalbasement Do you mean the one sitting in my basement? I haven't tried to power it on in years. I need to dig it out; it's in a fake leather carrying bag/case with handles. It has 48K of RAM, never had Apple 5.25-inch floppy drives, Franklin Ace ones instead!
[ Update: I dug it out, did not try to power it on yet. Yes, it's in the soft carry bag. The cover says "Apple ][", no plus, and it has the white square power light in the lower left corner of the keyboard. I'll look for Rev numbers on the mainboarď; not sure how to tell the different updated production versions. ]
The videos keep getting better and better. Good work!
I think that is more difficulty to work in digital electronic. I'm learning some things with you. I enjoy watching yours videos. God look.
Really enjoyed this video Adrian. Please do more Apple II videos. I have a IIE enhanced which has no beep or image at startup. I’ll take a look at those memory chips.