For people who strongly dislike soldering DIN connectors, plug them into another DIN connector while soldering to keep the pins straight and to dissipate the heat.
Yes, there’s also the potato merhod. ;) These quality Hirschmann plugs are actually really easy to work with, no melted plastics or dislocation pins at all. :)
This was my first computer. I still have it, along with the monitor, disk drive, tape, expansion interface and power supply. I’m pretty sure it is non working but hasn’t been out of the box in decades. I’ll be following these videos with much interest.
@@JanBeta Not me, I was fine with it. I would never have been able to see the smoke from your house from where I live. ;> That said, I'm not going to criticize what looks to be a fine homebrew power supply. Nice and tidy work there. Especially when I have antique tube radios where everything is exposed and the high voltage goes all over the place.
Owned a TRS-80 Model I which included monitor. I loved it as it was very reliable, though very, very limited. It cost around $500 in 1974 here in the US and was the first home computer to be manufactured commercially for the public. There was no Data storage at all, no hard driver, no color, no sound, other than beeps. All that came later, around the time the VIC 20 happened.
Wow, a great trip down memory lane for me. My first computer was a TRS-80 Model 1, Level II w/4KB of ram. The machine was under constant upgrade until I sold it years later to a writer who only wanted it to write his books with it.
Because you have double sided board you need to either remove all primary side past and remove traces on the top side of the board, or use a dremel and saw through the board to make the spark-gap through and through for security on both sides.
I have recently acquired the same TRS 80, from Texas. No psu, no cables, nothing but the computer itself. So need to acquire or build everything myself. But it was much cheaper then a fully working TRS. I had this machine when I was a kid., but lost that one.The keys sounded so cool and they still do
The last time I had to make a computer PSU (C-64) I just used two "wall worts" (9VAC, 5 VDC switching), removed the plastic and stuffed them into a plastic project box with fusing on the mains and both outputs. Seems to work fine and is a bit easier then making up a new PCB/perfboard. However what is important here is you use what you have around you and if it meets it's purpose then that's good enough. Nice job Jan. Cheers and hope you are doing OK,
Well, it didn't blow up and you aren't dead so that's a plus 😊 I am confident that you will get it sorted out and we can see it working. Looking forward to it. Cheers
The board looks like they used a CAD software. That is pretty amazing for 1978. Lots of consumer level PC boards were actually hand drawn in those days, that is why we see smooth curving lines rather than angled bends. A great piece of history this is!...
Good morning :) I've got here one TRS80 without power supply as well, got it a few months back from USA for dirt cheap as non-working (actually working, but bad RAM at least, how unexpected :P). Glad to see some other European fixing it as well! :)
I didn't know the Model 1 is a computer-in-a-keyboard! I've got a Model III here that's a big all-in-one with monitor and disk drive built-in and assumed Model I and II would have built-in monitor too. Neat. Also, I missed the invite for #SepTandy, I must not be cool enough!
Yes, the later incarnations were all-in-one. Even rarer to find over here it seems, unfortunately. Lovely machines. I so hope I can get this one to work. And, hey, you are definitely cool enough to join SepTandy, everybody is welcome to post videos with the hashtag. You are going to be added to the playlist for sure if you publish something. :)
As Jan already said you are certainly cool enough Robin. Maybe you could find some Tandy Easter eggs, I always enjoy those ones (and your other videos too)
Thanks guys, I should have added a winky after my not cool enough comment ;) @TheRetroChannel I did show one Tandy Easter Egg in the video about the supposed "Bill Gates Sucks" egg; I've heard of a couple more since. If there isn't a good video about them yet, I'll do that. @WolfKenneth Yeah, there's later Tandy computers like the CoCo series and Model 100 that are computer-in-keyboard (without built-in monitor), I was just surprised the Model 1 was in that category when the Model 2 & 3 are not.
Good work. Just a couple ideas.... I would probably change the way the fuse is wired as the mains should always go into the fuse first, not the power switch. Also implement some type of protection circuit, like a crowbar, which would be simple and only require a handful of components (a couple resistors, zener diode, 100nf cap, and an SCR).
Well done Jan. Very inventive. I won't add to the chorus on the double sided perf board; but I did cringe. Any moisture in there and... Well, good job rethinking it.
To make bigger isolation gaps on perf board i just turn the soldering iron up to max, hold it on the unwanted pads for a few seconds and they will come off.
As part of my degree in the 80s, we learned Z80 machine code on the TRS-80s. They were, by 1984/85, really high mileage, and you had to sort of assemble working peripherals before you could use them reliably. It made the module a lot more fraught than it needed to be.
A single sided surfboard got it, lol. Joking aside, I'm actually surprised that the ribbon cable in the middle still has continuity after all this time that's literally a common fault of these things most people have had to replace it anyway since bending it a few times now just ruins it. Otherwise ya got me on this one I know little about the TRS's. Danke Jan!
I would have used some kind of Buck converters for the two different voltages required myself. and not use any perfboard for the project. I also would have used the IEC connector with integral fuse holder and power switch. you can find them on Amazon.
Jan, I am a new subscriber and first time commenter. I learned a lot watching how you put together your power supply case. Have been looking for a good video showing how to put together a case and unexpectedly this trs80 video provided the clearest example I’ve seen to date. Thanks and well done from a new electronic hobbyist.
A fantastic #SEPTANDY project. This poor TRS-80 needs some serious love and it is definitely in good hands. Awesome job with the new PSU and discovering the hidden C64 colour under the silver paint 😉. Looking forward to part 2. Apologies for the lazy comment (copied from my Patreon comment 😜).
First video I see in the TRS80 video series and I love it :) Mostly offf the shelf components? nice, maybe this is a good candidate for replica boards :)
Me, too! Then I used to go to the one in Stockton. It was sad when it closed, but I got some stuff in the closing down sale, like an amp which I still use for my C64s and Amigas.
Gate a ready made PCB possibly from PCB WAY only to match up with the components you already have chosen and you can have them route out the spark gaps for you. I remember when that TRS-80 Model 1 came out. I just wanted one to write programs on but did not yet have the cash flow to purchase one. Commodore was not even on my radar. I only knew two people in my life who ever owned and used Tandy Computers which was the TRS-80 Model 1 and later my friends dad had a COCO with Chicklet Keys which I believe was the COCO2 or something like that. By that time I was mucking around with a VIC-20 and a TRS80-PC1 Pocket Computer. Other than that the only other Tandy I ever owned was a Tandy HX1000 which I did not make much use of because when I acquired it I was using a bunch of Commodore 8 bit computers 64, 128, 128D all sharing a Lt Kernal HD System through a Multiplexor and I had and was using A1000, A500 and A2000HD so the PC Side was not of much interest to me at the time. I ended up giving that Tandy HX1000 away to a friend so she could run a terminal program to call BBS's including the one I ran which was a C-Net Amiga Pro BBS called Compiler Net Amiga which ran from 1987 to 1997 first running on a C128 in 64 mode then on a 128D in 128 Mode and then on the Amiga running multiple phone lines. Sorry I rambled on a bit too much.
Yes, I'm probably going to end up designing a proper PCB for the power supply at some point. I needed something to work with for now. In the meantime, I removed some more copper and it should be at least a bit safer to use now.
If you can't get the Garbage Screen to show up, there is a problem with the video circuitry. I once fixed a TRS-80 that had exactly this problem - there are a few discrete transistors, the sync transistor pulls the signal low, if this transistor is bad or the chip that should provide it is dead, then you will get a video signal that's so weak, you'll need to set the oscilloscope to a few 100 mV per division to see anything at all.
Very experimental power supply. But it looks like its working fine. I am having an identical problem with my c128 5V rail and i am very interested in what you are doing next to solve this problem. Great video, Jan!
With the power supply, it's a case off *Do as i say* *Not! as i do* OR use PCBWay for a safer power supply Board. I'm sure 1 of the other 9 Included TH-camrs, involved with this, could get one made ready for when it's there turn. 👍
I did some more work on the PSU and removed more copper so it should be a bit safer now. Probably going to end up designing a proper PCB at some point but I wanted to have something to test the machine with for now.
Wooah! 😲 The best advice came at the end - don't do it this way! First thoughts near the start were "he needs to flip the board over" - then I realised you were using double sided perfboard. Never a good idea with power boards. Yes, the toroidal transformers are relatively expensive but they are smaller and have a higher power rating than the ones you used. As regards a "spark gap" the in-air insulation distance for 240V (peaking at something over 300V and depending on environmental conditions) is in the order of 1/100th of a mm and so is not really a factor in this case. If it were you would need to create a gap on the top side of your board too as it's very likely that the solder will have bridged the transformer connections to the top surface pads. The cable you used from the PSU to the computer is MASSIVE overkill! It would likely take 10A over a few meters and would likely have a resistance of only few milliohms per meter (easily measured with your multimeter) - producing only a few millivolts of drop over the lengths required. Not really an issue. I bet it was fun soldering those thick cores into the DIN plug! You may also find it easier to strip the sheath and individual conductors BEFORE feeding it through the grommet. You make a point that you have attached the earth connection - but to what? If it just goes into the terminal block and no further then it's pointless. However it should be connected to the mounting screws unless you use plastic screws - these are the only parts that could potentially be live, not by sparks jumping but by the power wires working themselves out of the terminal block and contacting the board surface (one major reason to use single sided boards). Working with 12V and 5V is fine and safe but you need to be MUCH more careful when working with mains power.
It's a great way for prototyping a circuit in my opinion. (Although GreatScott! obviously is way more sophisticated and actually knows what he's doing...)
I love it! I think I'm going to have to give you an award called "Biggest Brass Pair". The trophy will, ironically, be made of perfboard.. but seriously, very cool video!
I ran my wholesale camera repair business on that machine. By the time I maxed it out at 48KB RAM, four Mitsubishi DSDD half-height drives (720KB each), and, an IDS printer (7 pin, monodirectional printing, no descenders for lower case (7 pins!), and a sheet metal cabinet that resonated with the steel bar platen -- enhanced by the solenoid line feed (THREE loud bangs per line -- in case I wanted to add the graphics ROM), it was... very unpleasant when we printed statements every month (and also when we printed invoices daily, but not nearly so long as the monthly statements). Anyway, by the time I'd built it out to that (and I used a 9" Sony CCTV monitor instead of the overpriced RCA "Sportable" TV with its guts pared down to the bare minimum so it could function as a composite monitor) -- by that time, I'd sunk something like 37 hundred dollars into it. And those were circa 1980 dollars, so, do the math to see how many inflated dollars those would be four decades later. Kids today are SO spoiled, I tell ya... Seriously!
PS: By "on that machine" I mean a TRS-80 Mod 1 -- not the actual machine in this video. (Mine was SO early -- the third one sold in my region -- that it didn't have the numeric keypad.)
PPS: I added lower-case using the instructions in the Dennis Bathory Kitsz newsletter (I'm sure there'll be a bunch of info if you type his name into a search engine). I piggybacked a 74LS02 (IIRC) -- a 1KB static RAM chip -- over one of the existing video RAM chips. Some of the pins were bent outward, with wire soldered to them going... somewhere, and the rest of the pins were soldered onto the chip it was piggybacking. I then kludged (that's geekspeek for "melted holes with my soldering pencil") mounting for two surplus calculator keys, which became Ctrl keys (lacking on the native keyboard). When i was done, I also had to use a driver he wrote in Z80 Assembly (or perhaps he wrote it in straight machine language -- it was fairly compact, and he was smarter than a barrel full of me's). It worked great! (Well, great, apart from the lack of descenders on the display -- a foot-dragging artifact it shared with the printer.) And so, I used it for more years than I'd care to think about -- it was always crashing, often needing a strong whack upside the cabinet (I had an employee rig up a plywood cabinet for the computer/keyboard, Expansion Interface, and monitor). I am serious -- it often needed a good solid whack to unlock it. The thing was plagued with poor connections -- they used nickel, or maybe silver, where they should have used gold. They cut every corner they could on that thing -- it was a _horrible_ design! Went in for warranty service nearly twenty times, before I gave up. They kept extending the warranty each time they'd try to fix it for a couple/few weeks each time. In the end I must have held some record for the longest warranty for that model. It went through five or six main board replacements, and still it kept going back. It got to where I'd insist on powering it up on the counter at the store before taking it home, and more than once it locked up the first time it was turned on! The store manager would say it's fixed! I'd say let's see about that. And not one minute later, he had taken it in for repairs. Again. But, it _was_ the best/cheapest thing going for someone who couldn't afford an S100 machine and wanted a LOT of aftermarket support. I ran NEWDOS-80 for the longest time, the original TRSDOS was awful, should have called it POSDOS. At the end (at this point I was using a Model 4 and a Model 4P), "TRSDOS" was just a rebadged LDOS which Tandy licensed, and it was an _excellent_ OS. I could have run CP/M on it -- one with everything relocated (necessary due to the hardware memory mapping for I/O in the TRS80 Model 1 and Model 3, or, the Model 4 when running in Model 3 mode), or, "regular" CP/M for the Model 4 in native mode. But, everyone wanted CP/M 2.2 -- but Tandy only ported CP/M 3.0, which was a path pretty much no one else took. So, I stuck with LDOS and NEWDOS80. Ah, memories... (I sold he 4P probably 30 years ago, but still have the Model 4 somewhere. The switching PS blew out after the warranty expired, but IIRC it was a fairly stndard 12VDC affair, and, this being the era during which you couldn't just go on Ebay and buy a 12V switching supply from china, I tossed in a nice hefty _linear_ 12VDC supply, and it ran like a top ever since. It _weighed_ more, but heck, it wasn't going anywhere! At the end, I had a nice Tandy-rebadged Toshiba 24 pin printer -- _beautiful_ letter quality printing, you'd think it came from a daisy wheel or laser printer, it was _that_ nice -- and not _nearly_ as loud as that $1,200 IDS monstrosity (argh!) Ah, memories.... but I repeat myself.
I'm probably going to design a proper PCB at some point (and have PCBWay produce it) but I need to test it first, hence the cobbled together DIY approach.
I would have put the LED on the output end where it can be seen. The input end is not optimal if you really think about it. You could still move it. ;) It is a good project though, perfboard notwithstanding. I predict in Part 3, you will transfer the components to a proper PCB. :D
Thanks! As you have seen, I did some more refinements on the PSU board now. Should at least be a bit safer. I'm probably going to end up designing a proper PCB at some point, just need this to test the circuit and the machine for now.
Hehe... I have two Fairchild Channel Fs (SABA Videoplay - both models actually). The old one has a CPU from 77 that still works. The newer one had the CPU go bad just half a year ago... now it's one from 85.
Hehe² - if we enter a "Who has the oldest CPU", it doesn't necessarily mean microprocessor - I have a Compucorp 322G Scientist programmable calculator from 1972 - it has a CPU board made out of discrete chips. Amazing what some people throw in the dumpster...
If you had and earth in the mains cord and connected the output 0V lead to the earth then it would at least fail safe in the event of a mains isolation fault.
Been there, too, actually. These Victorinox knives are invaluable multi-purpose tools for me. I never leave the house without at least a small keychain one. :)
Why. You've already built that one and it works fine. Its cheaper than a custom PCB and you don't need to wait days for it to arrive. If you already have the stripboard and components, you can just get on with building it now.
I'm a bit jealous! I really would like to have a TRS-80 model 1 as a companion for my Video Genie. Hope you can fix it! But I think it was not the best idea to let the system be powered that long with all the 4116 RAMs in place... They tend to die fast when the voltages aren't spot on...
Oh, good point. They are getting at least most of the voltage they need so I hope they did hold up. I have plenty of spares if they didn't. Any plans for VideoGenie videos from you? You could tag it with SepTandy and we can add you to the Playlist. :) Would be an interesting addition to see that glorious machine, too.
@@JanBeta not that I didn't have the idea for myself. But I'm still short of time. Life came in the way. We did house renovations and I was enjoying summer. And I try to get some quality time with friends during this pandemic times.
Cheaters way: Use the 19VAC transformer brick from a PCJr and 19VDC PSU from a laptop that uses the 2.5mm barrel jack (Toshiba and Acer use these most commonly). Dell power supplies use 19VDC as well but they have a 3 pin arrangement (outer shell, inner shell, and core) One of those lines is a wattage sense line to allow the laptop to reject a power supply if it does not claim to produce sufficient wattage.
the green-yellow wire should only be intended to carry chassis ground as a standard. It's not that bad but it looks ugly to me. Are the transformers mechanically fixed with screws too or they are fixed only with the soldered wires on the board?
I had one of those Model 1s with monitor and disk drive.. gave it away though.. didn't have the room for it. However, if September is SepTandy, then surely October is Octommodore?
Yeah, you could inject the proper voltages on the board I guess. Might still be an option if everything else fails. Until then I try to preserve the original circuit as much as possible. ;)
A few days ago I found a Philips TV/Monitor from 2011 in the trash, the outer bezel is cracked (easy fix) and someone shoved wood screws in two of the VESA mount studs (screw tap should fix that) and it's got no stand (it will be wall swivel mount!) but it works! It is going to be a Lips monitor just like yours :), I was so happy when I took it home and it works and has all of the old school inputs (S-video, composite, component) as well as 720p HDMI and VGA. Should I actually remove the printing or just put a piece of electrical tape on the name like your monitor? XD
@@JanBeta I hope it will be a nice test monitor for many years to come, found out it can even accept PAL and NTSC and even SECAM signals on composite, S-Video and RF which is fantastic and it's PC monitor resolution is pretty good too for testing purposes, really happy with this find, now I just gotta clean it up and fix the broken bezel.
Same here! I cut teeth on it (nearly my wrists, too! :) -- but after my camera repair business morphed into a computer building/sales business, and after my body was wrecked when a doped-up driver rear-ended me at an intersection, I focused entirely on software development -- wrote a (character mode) visual shell, which EVERYONE that used it _loved_ -- it made it easier to use DOS than Windows made it easy to run Windows programs -- but, just as I was getting ready to sign a distribution contract with a firm out East, Windows happened. Timing is everything, eh? So, I quickly added what I called "virtual runtime mode" -- (back then, most people had at most one or two Windows programs, all the rest being DOS software) so that people could run Windows programs using Windows as if it were a runtime version. (MSFT quit licensing runtime versions when 3.0 was released.) The way it worked was: You'd make an entry for the Windows program, and then check the box saying to run it in virtual runtime mode. You would then check off some other boxes, i.e., how to handle things when your program ended, such as do I remain in Windows, or do I return to the DOS shell? Then, whenever you'd run that program, the shell would create a command like to run Windows and a little background program I wrote in Visual Basic. My background program would monitor the program you were running in Windows, and when it ended, my little program would then do whatever you'd told it to do (IIRC exit Windows and return to the Shell, stay in Windows, or prompt you to ask if you wanted to stay in Windows). That worked great -- until Windows 95 hid MSDOS under the covers. Argh... Meanwhile, I was on some MSFT technical betas, met some people there, one of whom was a "scout" for a large publisher (Que), and to make an already too long story short, I ended up a Famous Author™ -- until my health deteriorated to the point that I could no longer even write any more magazine articles (I was also a Contributing Editor at Visual Studio Magazine.) So, my funky, expensive, comically limited TRS80 Mod1 put me into a career I'd always wanted. (Seriously. In fact, I'd sometimes in a dream have a book published -- and then I'd wake up, and... back in the real world. Sadly, I was later to discover that the thrill of seeing my name on the cover of a book was very short-lived. It was the royalty checks that mattered, not seeing my name in print.) The End
PS: My shell was an MSDOS shell -- but if not for the _years_ I spent honing the camera repair logging/tracking/billing software, I _never_ would have been able to put the DOS shell together -- or any of the Windows programs I later wrote. The funky TRS80 was the foundation. And crummy as it may have been compared to the "prestige" computers back in the day, well, all I can say is that I can't complain.
Actually at the end with the voltage being so low -- I'd say it is overloading the rail and dropping (considering it is resistor + zener diode "regulator"). So RAM chips? :)
Great video, as always! Just wondering, is there a particular reason to go live-switch-fuse instead of live-fuse-switch ? New idea: use a common-cathode dual color LED and have one of each color on each transformer, if the color is wrong, you lost one of the rails :)
A very bad choice of RF-video cable, using such a low grade audiocoax. Amazing that you'd even consider using it at all, when a cheap piece of antenna-cable to transfer RF is a much much better choice. If thickness is an issue, go find some good Belden with your preferred diameter. Just had to chime in. Thumbs up for the TRS-club. Great to see all these efforts around Planet Earth to restore all types of computers from the entire range throughout the decades. Cheers from Sonderburg, Dänemark.
It’s not an RF signal so an RF cable actually is not the ideal choice. But you are right, probably going to use a better cable at some point. This is just for testing until (if) I can get the machine to work. :)
@@JanBeta Of course. Just to see if there's throughput. Bandwidth ? 1-2-3 MHz Sorry. I was triggered ......and felt obliged to recommend better cabling. :) Now, you take care and have a great weekend.
Oh, the grommet itself is so tight that it provides a lot of strain relief already. The cable ties are just safety. I might add some glue, too, once I am sure that the PSU design works reliably.
@@JanBeta In the US/Canada we have what's called an "Underwriter's" or "Electrician's" knot that used in things like lamp fixtures to prevent the conductor getting snatched out of the contacts in the event of a fall. In the absence of a proper crimp style strain relief, that might be a good solution to keep two or three kilos of transformers and box from snatching the cord out if it falls off the bench while plugged in.
Nice work on the TRS-80! Regarding the PSU, I’ve used this IEC connector which incorporates also the power switch and the fuse. www.spelektroniikka.fi/p21594-kojerunkoliitin-iec-sulakerasialla-ja-virtakytkimella-vaaka-asennus-fi.html
Yes, but not enough to be safe I think. The pads are too close together. I think 1mm air gap is enough to be safe for around 100V. Solder mask reduces the risk of arcing a tiny bit though.
It would have been easier if you used a PC power supply, Five volts, and minus five volts are there, and so is 12 volts. For the price of one transformer you would have bought a complete working power supply. And it would have saved you a days work.
Oh, danke für den Tipp. Da ist eigentlich sogar schon ein Deesser auf der Audiospur, weil das kleine Lavalier die Höhen ziemlich betont. Vermutlich höre ich die hohen Frequenzen einfach nicht mehr so gut... I‘m an old man, y‘know... 😅
Ich kann mich nur schwach daran erinnern, dass man einen TRS80 aucnin Deutdchland kaufen konnte. Ich hatte mal einen Taschenrechner von Radio Shack. Using a perf board for use with high voltage is not a great idea, generally speaking. There are some safety issues which really need to be taken seriously. The Alternative would be to design a pcb especially for your design or, as you mentioned, get the pre made boards.
Here is my sponsor PCBWay....... where I should have ordered the proper PCB from 😂
Pronounced PCBWaaaaaaaay.
For people who strongly dislike soldering DIN connectors, plug them into another DIN connector while soldering to keep the pins straight and to dissipate the heat.
Yes, there’s also the potato merhod. ;)
These quality Hirschmann plugs are actually really easy to work with, no melted plastics or dislocation pins at all. :)
How true! I messed so much with these!
This was my first computer. I still have it, along with the monitor, disk drive, tape, expansion interface and power supply. I’m pretty sure it is non working but hasn’t been out of the box in decades. I’ll be following these videos with much interest.
Computer: comes with no PSU
Jan Beta: I make a new one
("my mechanics" reference) :P
*sees Jan using perfboard to handle mains current*
*runs to comments to see all the flames*
*is not disappointed*
LOL
It was to be expected... :D In the meantime, I refined the design a bit and removed a lot of copper to soothe everybody's nerves. ;)
@@JanBeta Not me, I was fine with it. I would never have been able to see the smoke from your house from where I live. ;>
That said, I'm not going to criticize what looks to be a fine homebrew power supply. Nice and tidy work there. Especially when I have antique tube radios where everything is exposed and the high voltage goes all over the place.
Owned a TRS-80 Model I which included monitor. I loved it as it was very reliable, though very, very limited. It cost around $500 in 1974 here in the US and was the first home computer to be manufactured commercially for the public. There was no Data storage at all, no hard driver, no color, no sound, other than beeps. All that came later, around the time the VIC 20 happened.
Wow, a great trip down memory lane for me. My first computer was a TRS-80 Model 1, Level II w/4KB of ram. The machine was under constant upgrade until I sold it years later to a writer who only wanted it to write his books with it.
Because you have double sided board you need to either remove all primary side past and remove traces on the top side of the board, or use a dremel and saw through the board to make the spark-gap through and through for security on both sides.
I have recently acquired the same TRS 80, from Texas. No psu, no cables, nothing but the computer itself. So need to acquire or build everything myself. But it was much cheaper then a fully working TRS. I had this machine when I was a kid., but lost that one.The keys sounded so cool and they still do
Mentions PCB Way as sponsor. Then makes breadboard, solder blob, circuit board PSU from scratch. Awesome. :)
I‘m probably going to make a proper board at some point, just needed something to test the design first. Still a faster way of prototyping.
The last time I had to make a computer PSU (C-64) I just used two "wall worts" (9VAC, 5 VDC switching), removed the plastic and stuffed them into a plastic project box with fusing on the mains and both outputs. Seems to work fine and is a bit easier then making up a new PCB/perfboard.
However what is important here is you use what you have around you and if it meets it's purpose then that's good enough. Nice job Jan.
Cheers and hope you are doing OK,
Well, it didn't blow up and you aren't dead so that's a plus 😊 I am confident that you will get it sorted out and we can see it working. Looking forward to it. Cheers
Haha, thanks. Ijn the meantime, I removed some more copper and made the PSU safer to use. Troubleshooting and hopefully fixing in progress now. :)
Excellent news 👌
Thanks Jan, I picked up one the other week to fix up (serial no: 065936); but most of the extra wires came loose - so I know where they go now 👍
The board looks like they used a CAD software. That is pretty amazing for 1978. Lots of consumer level PC boards were actually hand drawn in those days, that is why we see smooth curving lines rather than angled bends. A great piece of history this is!...
Yes, they seem to have used software to route the board. Probably being Radio Shack they had the resources. :)
Good morning :) I've got here one TRS80 without power supply as well, got it a few months back from USA for dirt cheap as non-working (actually working, but bad RAM at least, how unexpected :P). Glad to see some other European fixing it as well! :)
I didn't know the Model 1 is a computer-in-a-keyboard! I've got a Model III here that's a big all-in-one with monitor and disk drive built-in and assumed Model I and II would have built-in monitor too. Neat. Also, I missed the invite for #SepTandy, I must not be cool enough!
Yes, the later incarnations were all-in-one. Even rarer to find over here it seems, unfortunately. Lovely machines. I so hope I can get this one to work. And, hey, you are definitely cool enough to join SepTandy, everybody is welcome to post videos with the hashtag. You are going to be added to the playlist for sure if you publish something. :)
As Jan already said you are certainly cool enough Robin. Maybe you could find some Tandy Easter eggs, I always enjoy those ones (and your other videos too)
Robin, apologies, that’s my bad.
It’s kinda grown a bit this year and didn’t really know who to reach out to.
Wait aren't normal TRS-80 AIOs and CoCo home micro in keyboard? Tandy named a lot of different computers as trs-80
Thanks guys, I should have added a winky after my not cool enough comment ;)
@TheRetroChannel I did show one Tandy Easter Egg in the video about the supposed "Bill Gates Sucks" egg; I've heard of a couple more since. If there isn't a good video about them yet, I'll do that.
@WolfKenneth Yeah, there's later Tandy computers like the CoCo series and Model 100 that are computer-in-keyboard (without built-in monitor), I was just surprised the Model 1 was in that category when the Model 2 & 3 are not.
Good work. Just a couple ideas.... I would probably change the way the fuse is wired as the mains should always go into the fuse first, not the power switch. Also implement some type of protection circuit, like a crowbar, which would be simple and only require a handful of components (a couple resistors, zener diode, 100nf cap, and an SCR).
I agree on the fuse, a protection circuit is a bit overkill because there are some quite sophisticated protection circuits on board in the TRS-80.
Use bare perf board without pads, hot glue components down, then use insulated wire for point to point wiring.
No, thats messy. Jans way is neater.
Well done Jan. Very inventive. I won't add to the chorus on the double sided perf board; but I did cringe. Any moisture in there and... Well, good job rethinking it.
To make bigger isolation gaps on perf board i just turn the soldering iron up to max, hold it on the unwanted pads for a few seconds and they will come off.
Did that accidentally many times before but didn't think of doing it on purpose. Nice idea! :D
ElectroBOOM would have a field day with this PSU design.
Ha! Probably. I lack some explosions though. :D
Well, at least that PSU's prettier than what we come up with at school back in the day...
Nice! Manufactured on my birthday but 8 years before me :)
As part of my degree in the 80s, we learned Z80 machine code on the TRS-80s. They were, by 1984/85, really high mileage, and you had to sort of assemble working peripherals before you could use them reliably. It made the module a lot more fraught than it needed to be.
A single sided surfboard got it, lol. Joking aside, I'm actually surprised that the ribbon cable in the middle still has continuity after all this time that's literally a common fault of these things most people have had to replace it anyway since bending it a few times now just ruins it. Otherwise ya got me on this one I know little about the TRS's. Danke Jan!
I would have used some kind of Buck converters for the two different voltages required myself. and not use any perfboard for the project. I also would have used the IEC connector with integral fuse holder and power switch. you can find them on Amazon.
Talk to Sven, He is the man for PSU design.
Morning Jan. looking forward to watching this tonight .
Hope you enjoy it. :)
Jan, I am a new subscriber and first time commenter. I learned a lot watching how you put together your power supply case. Have been looking for a good video showing how to put together a case and unexpectedly this trs80 video provided the clearest example I’ve seen to date. Thanks and well done from a new electronic hobbyist.
A fantastic #SEPTANDY project. This poor TRS-80 needs some serious love and it is definitely in good hands. Awesome job with the new PSU and discovering the hidden C64 colour under the silver paint 😉. Looking forward to part 2. Apologies for the lazy comment (copied from my Patreon comment 😜).
First video I see in the TRS80 video series and I love it :) Mostly offf the shelf components? nice, maybe this is a good candidate for replica boards :)
Like this? hackaday.com/2020/01/19/trs-80-clone-uses-modern-parts/
trs trouble shooting can't wait - thanks Jan Enjoyed the video
Can't wait for part 2!
I love that you're wearing your Pixel Vixen shirt! I have the same one - it's awesome.
Yes! I’m eagerly waiting for the 8-bit line of shirts that Vicky is working on!
A friend of mine had a CoCo2 and a CoCo3. Good ol' "Trash 80"!
remember the tandy shop here in middlesbrough when i was a kid.....was like alladins cave
Oh, I can imagine that! No Tandy or Radio Shack shops in Germany as far as I know. But I loved visiting electronics stores as a kid. :)
Me, too! Then I used to go to the one in Stockton. It was sad when it closed, but I got some stuff in the closing down sale, like an amp which I still use for my C64s and Amigas.
Loved Tandy in Norwich, there was always so much stuff you thought you never needed!
Gate a ready made PCB possibly from PCB WAY only to match up with the components you already have chosen and you can have them route out the spark gaps for you. I remember when that TRS-80 Model 1 came out. I just wanted one to write programs on but did not yet have the cash flow to purchase one. Commodore was not even on my radar. I only knew two people in my life who ever owned and used Tandy Computers which was the TRS-80 Model 1 and later my friends dad had a COCO with Chicklet Keys which I believe was the COCO2 or something like that. By that time I was mucking around with a VIC-20 and a TRS80-PC1 Pocket Computer. Other than that the only other Tandy I ever owned was a Tandy HX1000 which I did not make much use of because when I acquired it I was using a bunch of Commodore 8 bit computers 64, 128, 128D all sharing a Lt Kernal HD System through a Multiplexor and I had and was using A1000, A500 and A2000HD so the PC Side was not of much interest to me at the time. I ended up giving that Tandy HX1000 away to a friend so she could run a terminal program to call BBS's including the one I ran which was a C-Net Amiga Pro BBS called Compiler Net Amiga which ran from 1987 to 1997 first running on a C128 in 64 mode then on a 128D in 128 Mode and then on the Amiga running multiple phone lines. Sorry I rambled on a bit too much.
Yes, I'm probably going to end up designing a proper PCB for the power supply at some point. I needed something to work with for now. In the meantime, I removed some more copper and it should be at least a bit safer to use now.
Great video Jan really enjoy your stuff!
Thanks! :)
If you can't get the Garbage Screen to show up, there is a problem with the video circuitry. I once fixed a TRS-80 that had exactly this problem - there are a few discrete transistors, the sync transistor pulls the signal low, if this transistor is bad or the chip that should provide it is dead, then you will get a video signal that's so weak, you'll need to set the oscilloscope to a few 100 mV per division to see anything at all.
Very experimental power supply. But it looks like its working fine. I am having an identical problem with my c128 5V rail and i am very interested in what you are doing next to solve this problem. Great video, Jan!
Troubleshooting is in progress. Thankfully, the documentation is really good. I hope to get this machine running again soon. :)
You could use a laptop power supply for the DC part.
With the power supply, it's a case off *Do as i say* *Not! as i do* OR use PCBWay for a safer power supply Board.
I'm sure 1 of the other 9 Included TH-camrs, involved with this, could get one made ready for when it's there turn. 👍
I did some more work on the PSU and removed more copper so it should be a bit safer now. Probably going to end up designing a proper PCB at some point but I wanted to have something to test the machine with for now.
@@JanBeta I seen your Twitter update Jan, I'm pleased to see you corrected the (isolation gap) Big Respect, Top Man! 👍
A rubber gromit, bit no cheese gromit?? Lol
wicket video man can't wait for part 2
Excellent video Jan. You just made me order more stuff on ebay now :)
Thanks! Hope your ebay conquest was successful. ;)
Wooah! 😲 The best advice came at the end - don't do it this way! First thoughts near the start were "he needs to flip the board over" - then I realised you were using double sided perfboard. Never a good idea with power boards. Yes, the toroidal transformers are relatively expensive but they are smaller and have a higher power rating than the ones you used. As regards a "spark gap" the in-air insulation distance for 240V (peaking at something over 300V and depending on environmental conditions) is in the order of 1/100th of a mm and so is not really a factor in this case. If it were you would need to create a gap on the top side of your board too as it's very likely that the solder will have bridged the transformer connections to the top surface pads. The cable you used from the PSU to the computer is MASSIVE overkill! It would likely take 10A over a few meters and would likely have a resistance of only few milliohms per meter (easily measured with your multimeter) - producing only a few millivolts of drop over the lengths required. Not really an issue. I bet it was fun soldering those thick cores into the DIN plug! You may also find it easier to strip the sheath and individual conductors BEFORE feeding it through the grommet. You make a point that you have attached the earth connection - but to what? If it just goes into the terminal block and no further then it's pointless. However it should be connected to the mounting screws unless you use plastic screws - these are the only parts that could potentially be live, not by sparks jumping but by the power wires working themselves out of the terminal block and contacting the board surface (one major reason to use single sided boards). Working with 12V and 5V is fine and safe but you need to be MUCH more careful when working with mains power.
Seeing you do the solder on the Perf Board to make a PCB reminds me of watching @GreatScott! Haha
It's a great way for prototyping a circuit in my opinion. (Although GreatScott! obviously is way more sophisticated and actually knows what he's doing...)
I love it! I think I'm going to have to give you an award called "Biggest Brass Pair". The trophy will, ironically, be made of perfboard.. but seriously, very cool video!
I ran my wholesale camera repair business on that machine. By the time I maxed it out at 48KB RAM, four Mitsubishi DSDD half-height drives (720KB each), and, an IDS printer (7 pin, monodirectional printing, no descenders for lower case (7 pins!), and a sheet metal cabinet that resonated with the steel bar platen -- enhanced by the solenoid line feed (THREE loud bangs per line -- in case I wanted to add the graphics ROM), it was... very unpleasant when we printed statements every month (and also when we printed invoices daily, but not nearly so long as the monthly statements).
Anyway, by the time I'd built it out to that (and I used a 9" Sony CCTV monitor instead of the overpriced RCA "Sportable" TV with its guts pared down to the bare minimum so it could function as a composite monitor) -- by that time, I'd sunk something like 37 hundred dollars into it.
And those were circa 1980 dollars, so, do the math to see how many inflated dollars those would be four decades later.
Kids today are SO spoiled, I tell ya...
Seriously!
PS: By "on that machine" I mean a TRS-80 Mod 1 -- not the actual machine in this video. (Mine was SO early -- the third one sold in my region -- that it didn't have the numeric keypad.)
PPS: I added lower-case using the instructions in the Dennis Bathory Kitsz newsletter (I'm sure there'll be a bunch of info if you type his name into a search engine). I piggybacked a 74LS02 (IIRC) -- a 1KB static RAM chip -- over one of the existing video RAM chips. Some of the pins were bent outward, with wire soldered to them going... somewhere, and the rest of the pins were soldered onto the chip it was piggybacking.
I then kludged (that's geekspeek for "melted holes with my soldering pencil") mounting for two surplus calculator keys, which became Ctrl keys (lacking on the native keyboard).
When i was done, I also had to use a driver he wrote in Z80 Assembly (or perhaps he wrote it in straight machine language -- it was fairly compact, and he was smarter than a barrel full of me's).
It worked great! (Well, great, apart from the lack of descenders on the display -- a foot-dragging artifact it shared with the printer.)
And so, I used it for more years than I'd care to think about -- it was always crashing, often needing a strong whack upside the cabinet (I had an employee rig up a plywood cabinet for the computer/keyboard, Expansion Interface, and monitor). I am serious -- it often needed a good solid whack to unlock it. The thing was plagued with poor connections -- they used nickel, or maybe silver, where they should have used gold. They cut every corner they could on that thing -- it was a _horrible_ design! Went in for warranty service nearly twenty times, before I gave up. They kept extending the warranty each time they'd try to fix it for a couple/few weeks each time. In the end I must have held some record for the longest warranty for that model. It went through five or six main board replacements, and still it kept going back.
It got to where I'd insist on powering it up on the counter at the store before taking it home, and more than once it locked up the first time it was turned on! The store manager would say it's fixed! I'd say let's see about that. And not one minute later, he had taken it in for repairs. Again.
But, it _was_ the best/cheapest thing going for someone who couldn't afford an S100 machine and wanted a LOT of aftermarket support. I ran NEWDOS-80 for the longest time, the original TRSDOS was awful, should have called it POSDOS. At the end (at this point I was using a Model 4 and a Model 4P), "TRSDOS" was just a rebadged LDOS which Tandy licensed, and it was an _excellent_ OS.
I could have run CP/M on it -- one with everything relocated (necessary due to the hardware memory mapping for I/O in the TRS80 Model 1 and Model 3, or, the Model 4 when running in Model 3 mode), or, "regular" CP/M for the Model 4 in native mode. But, everyone wanted CP/M 2.2 -- but Tandy only ported CP/M 3.0, which was a path pretty much no one else took. So, I stuck with LDOS and NEWDOS80.
Ah, memories... (I sold he 4P probably 30 years ago, but still have the Model 4 somewhere. The switching PS blew out after the warranty expired, but IIRC it was a fairly stndard 12VDC affair, and, this being the era during which you couldn't just go on Ebay and buy a 12V switching supply from china, I tossed in a nice hefty _linear_ 12VDC supply, and it ran like a top ever since. It _weighed_ more, but heck, it wasn't going anywhere!
At the end, I had a nice Tandy-rebadged Toshiba 24 pin printer -- _beautiful_ letter quality printing, you'd think it came from a daisy wheel or laser printer, it was _that_ nice -- and not _nearly_ as loud as that $1,200 IDS monstrosity (argh!)
Ah, memories.... but I repeat myself.
Next up, Octari.
We are already discussing DOScember, too. ;)
lol I'm surprised you didn't go with PCBWaaaaaaaaaaay!!!!! for this.
For Jan, PCB stands for Probably Can't Bother (to use his sponsor).
I'm probably going to design a proper PCB at some point (and have PCBWay produce it) but I need to test it first, hence the cobbled together DIY approach.
Jan Beta cobbled together DIY approach = prototype
I would have put the LED on the output end where it can be seen. The input end is not optimal if you really think about it. You could still move it. ;)
It is a good project though, perfboard notwithstanding. I predict in Part 3, you will transfer the components to a proper PCB. :D
Nice video Jan. I think you would be better off etching a board to make sure you have proper isolation. All the best.
Thanks! As you have seen, I did some more refinements on the PSU board now. Should at least be a bit safer. I'm probably going to end up designing a proper PCB at some point, just need this to test the circuit and the machine for now.
Hehe... I have two Fairchild Channel Fs (SABA Videoplay - both models actually). The old one has a CPU from 77 that still works. The newer one had the CPU go bad just half a year ago... now it's one from 85.
Hehe² - if we enter a "Who has the oldest CPU", it doesn't necessarily mean microprocessor - I have a Compucorp 322G Scientist programmable calculator from 1972 - it has a CPU board made out of discrete chips. Amazing what some people throw in the dumpster...
Ah my first computer was the Model I! Nice!
Mine was a model 3. Traded 2 or 3 NES games for it.
...or maybe make a board at PCBWay???
Yes, I'm probably going to design a proper PCB for this at some point.
😍😍😍😍😍 TRS 80 LOVE!!!
If you had and earth in the mains cord and connected the output 0V lead to the earth then it would at least fail safe in the event of a mains isolation fault.
Could you use nail polish over the back of the perf board as a kind of conformal coating to reduce the chance of sparking or shorting?
Yes, that helps a bit with separation but not significantly. I removed more copper plating in the meantime so the PSU should be relatively safe now.
1978 rules!
Haha, yes!
@@JanBeta I was "made" 5 Days earlier as the TRS 80
Agreed.
your swiss army knife is running mine pretty close for whose has had a harder life....have been known to use mine as a hammer lol
Been there, too, actually. These Victorinox knives are invaluable multi-purpose tools for me. I never leave the house without at least a small keychain one. :)
You need to remove pads between AC MAINS inputs under the transformers on the top of the perfboard - the gaps are too small.
Yes, did that in the meantime. I‘ll probably end up rebuilding the PSU properly at some point, too.
Why. You've already built that one and it works fine. Its cheaper than a custom PCB and you don't need to wait days for it to arrive. If you already have the stripboard and components, you can just get on with building it now.
I'm a bit jealous! I really would like to have a TRS-80 model 1 as a companion for my Video Genie. Hope you can fix it! But I think it was not the best idea to let the system be powered that long with all the 4116 RAMs in place... They tend to die fast when the voltages aren't spot on...
Oh, good point. They are getting at least most of the voltage they need so I hope they did hold up. I have plenty of spares if they didn't. Any plans for VideoGenie videos from you? You could tag it with SepTandy and we can add you to the Playlist. :) Would be an interesting addition to see that glorious machine, too.
@@JanBeta not that I didn't have the idea for myself. But I'm still short of time. Life came in the way. We did house renovations and I was enjoying summer. And I try to get some quality time with friends during this pandemic times.
Cheaters way: Use the 19VAC transformer brick from a PCJr and 19VDC PSU from a laptop that uses the 2.5mm barrel jack (Toshiba and Acer use these most commonly). Dell power supplies use 19VDC as well but they have a 3 pin arrangement (outer shell, inner shell, and core) One of those lines is a wattage sense line to allow the laptop to reject a power supply if it does not claim to produce sufficient wattage.
You need the center tap for the negative 5V actually, so that would not be the proper way to do it.
Thanks for TRS80 vid, that what i missed :-) from you
I am think this power supply îs verry good and loock nice
Can you make a variabile bench power supply
the green-yellow wire should only be intended to carry chassis ground as a standard. It's not that bad but it looks ugly to me. Are the transformers mechanically fixed with screws too or they are fixed only with the soldered wires on the board?
I had one of those Model 1s with monitor and disk drive.. gave it away though.. didn't have the room for it.
However, if September is SepTandy, then surely October is Octommodore?
Then next year can we have Aptari or Augtari?
Another one born in 1978 here too.
David L. Jones from the eevblog; what no magic smoke ?
I just poop on everything when I see a bad old PSU and put a Pico-PSU in it. :D
Yeah, you could inject the proper voltages on the board I guess. Might still be an option if everything else fails. Until then I try to preserve the original circuit as much as possible. ;)
A few days ago I found a Philips TV/Monitor from 2011 in the trash, the outer bezel is cracked (easy fix) and someone shoved wood screws in two of the VESA mount studs (screw tap should fix that) and it's got no stand (it will be wall swivel mount!) but it works! It is going to be a Lips monitor just like yours :), I was so happy when I took it home and it works and has all of the old school inputs (S-video, composite, component) as well as 720p HDMI and VGA. Should I actually remove the printing or just put a piece of electrical tape on the name like your monitor? XD
Haha, nice! LIPS brand monitors are the best! :D
@@JanBeta I hope it will be a nice test monitor for many years to come, found out it can even accept PAL and NTSC and even SECAM signals on composite, S-Video and RF which is fantastic and it's PC monitor resolution is pretty good too for testing purposes, really happy with this find, now I just gotta clean it up and fix the broken bezel.
So we have septandy... can we get AugAmiga next year too :P
There‘s secret plans for every month now, I think. :D
There should be also month for Amstrad/Sinclair
Watch the 2020 movie Knives Out! It's a great movie and you get to see 3 TRS-80 monitors used in a surveillance system. 😊
That's the first computer I ever programmed.
Same here! I cut teeth on it (nearly my wrists, too! :) -- but after my camera repair business morphed into a computer building/sales business, and after my body was wrecked when a doped-up driver rear-ended me at an intersection, I focused entirely on software development -- wrote a (character mode) visual shell, which EVERYONE that used it _loved_ -- it made it easier to use DOS than Windows made it easy to run Windows programs -- but, just as I was getting ready to sign a distribution contract with a firm out East, Windows happened.
Timing is everything, eh?
So, I quickly added what I called "virtual runtime mode" -- (back then, most people had at most one or two Windows programs, all the rest being DOS software) so that people could run Windows programs using Windows as if it were a runtime version. (MSFT quit licensing runtime versions when 3.0 was released.)
The way it worked was: You'd make an entry for the Windows program, and then check the box saying to run it in virtual runtime mode. You would then check off some other boxes, i.e., how to handle things when your program ended, such as do I remain in Windows, or do I return to the DOS shell?
Then, whenever you'd run that program, the shell would create a command like to run Windows and a little background program I wrote in Visual Basic. My background program would monitor the program you were running in Windows, and when it ended, my little program would then do whatever you'd told it to do (IIRC exit Windows and return to the Shell, stay in Windows, or prompt you to ask if you wanted to stay in Windows).
That worked great -- until Windows 95 hid MSDOS under the covers. Argh...
Meanwhile, I was on some MSFT technical betas, met some people there, one of whom was a "scout" for a large publisher (Que), and to make an already too long story short, I ended up a Famous Author™ -- until my health deteriorated to the point that I could no longer even write any more magazine articles (I was also a Contributing Editor at Visual Studio Magazine.)
So, my funky, expensive, comically limited TRS80 Mod1 put me into a career I'd always wanted. (Seriously. In fact, I'd sometimes in a dream have a book published -- and then I'd wake up, and... back in the real world. Sadly, I was later to discover that the thrill of seeing my name on the cover of a book was very short-lived. It was the royalty checks that mattered, not seeing my name in print.)
The End
PS: My shell was an MSDOS shell -- but if not for the _years_ I spent honing the camera repair logging/tracking/billing software, I _never_ would have been able to put the DOS shell together -- or any of the Windows programs I later wrote. The funky TRS80 was the foundation. And crummy as it may have been compared to the "prestige" computers back in the day, well, all I can say is that I can't complain.
Great video as always :-)
Thanks! :)
Actually at the end with the voltage being so low -- I'd say it is overloading the rail and dropping (considering it is resistor + zener diode "regulator"). So RAM chips? :)
Yes, one of my main suspects, too. We‘ll see in the next episode. ;)
@@JanBeta Just pull out the socketed RAM chips, and measure the voltage again.
LOVE IT AWESOME
Great video, as always!
Just wondering, is there a particular reason to go live-switch-fuse instead of live-fuse-switch ?
New idea: use a common-cathode dual color LED and have one of each color on each transformer, if the color is wrong, you lost one of the rails :)
I've seen it argued that if you change the fuse while it's plugged in, the power switch (in the off position) could potentially save you.
@@DaveMcAnulty Ah makes sense. I was aware of which way to solder the fuse holder, but didn't think of that possibility. Thanks ! :)
Doesn't hurt to have a ground. But please use yellow/green bi-color insulation cable only for ground!!
A very bad choice of RF-video cable, using such a low grade audiocoax. Amazing that you'd even consider using it at all, when a cheap piece of antenna-cable to transfer RF is a much much better choice.
If thickness is an issue, go find some good Belden with your preferred diameter.
Just had to chime in. Thumbs up for the TRS-club. Great to see all these efforts around Planet Earth to restore all types of computers from the entire range throughout the decades.
Cheers from Sonderburg, Dänemark.
It’s not an RF signal so an RF cable actually is not the ideal choice. But you are right, probably going to use a better cable at some point. This is just for testing until (if) I can get the machine to work. :)
@@JanBeta Of course. Just to see if there's throughput. Bandwidth ? 1-2-3 MHz
Sorry. I was triggered ......and felt obliged to recommend better cabling. :)
Now, you take care and have a great weekend.
ah, a fellow child of 1978 :)
How years have you soldering iron
Watched all the way, as always very interesting, dont know this systeem and i am looking forward to see how you get it to work.
It means you still are the oldest computer in your inventory hahaha.
Ha, didn't think of it that way. You are right... :D
do u know about the Dragon 32 or 64 at all? thanks. i wanted help with a program i typed in thanks.
I wouldn't trust those zip ties as a strain relief!
Oh, the grommet itself is so tight that it provides a lot of strain relief already. The cable ties are just safety. I might add some glue, too, once I am sure that the PSU design works reliably.
@@JanBeta In the US/Canada we have what's called an "Underwriter's" or "Electrician's" knot that used in things like lamp fixtures to prevent the conductor getting snatched out of the contacts in the event of a fall. In the absence of a proper crimp style strain relief, that might be a good solution to keep two or three kilos of transformers and box from snatching the cord out if it falls off the bench while plugged in.
Er war mein erster Computer. Ich habe ihn 1979 gekauft und habe noch alles komplett. Anleitung, ein Kassettenrekorder usw. Bei Interesse antworten.
Nice work on the TRS-80! Regarding the PSU, I’ve used this IEC connector which incorporates also the power switch and the fuse. www.spelektroniikka.fi/p21594-kojerunkoliitin-iec-sulakerasialla-ja-virtakytkimella-vaaka-asennus-fi.html
would soldermask paint help?
Yes, but not enough to be safe I think. The pads are too close together. I think 1mm air gap is enough to be safe for around 100V. Solder mask reduces the risk of arcing a tiny bit though.
It would have been easier if you used a PC power supply, Five volts, and minus five volts are there, and so is 12 volts. For the price of one transformer you would have bought a complete working power supply. And it would have saved you a days work.
But I would have to inject the voltages into the board circumventing the original circuit. I kind of try to keep it as original as possible.
You could of just varnished the board to stop arcing! Good job tho bud!
Yes, coating the board would help a bit. In the meantime, I removed some more copper and the PSU should at least be a bit safer now.
I Have to buy a desoldering Iron can you recomand me someting
Check near the bottom of the video information - Jan provides a link to the equipment he uses.
Why not recap the mainboard?
Coming up in Part 2. I needed a PSU first. ;)
Jan Beta Nice this computer looks awesome
Hey Jan, bitte überprüf mal dein Audio-Setup. Wenn du laut sprichst zischen die S-Laute usw. ziemlich stark, es tut ein bisschen in den Ohren weh.
Oh, danke für den Tipp. Da ist eigentlich sogar schon ein Deesser auf der Audiospur, weil das kleine Lavalier die Höhen ziemlich betont. Vermutlich höre ich die hohen Frequenzen einfach nicht mehr so gut... I‘m an old man, y‘know... 😅
@@JanBeta Und ich hab leider recht empfindliche Ohren 🙈.. ist aber hauptsächlich im Intro, später nur ab und zu mal kurz.
"Kinda of a design flaw" LOL
missing the 8-bit guy in the list ... but anyway ...good content
Oh, I think the 8-bit guy has plenty of projects going. Maybe next year!
Ich kann mich nur schwach daran erinnern, dass man einen TRS80 aucnin Deutdchland kaufen konnte. Ich hatte mal einen Taschenrechner von Radio Shack.
Using a perf board for use with high voltage is not a great idea, generally speaking. There are some safety issues which really need to be taken seriously. The Alternative would be to design a pcb especially for your design or, as you mentioned, get the pre made boards.