C128 fix and a disk drive voltage conversion 

Disk notchers - I remember when I found out about notching the corner of a disk and suddenly having a whole other side of the disk free to use. Blew my mind! Well doesn’t take much to blow the mind of a 9-10 year old kid. I spent an afternoon carefully measuring and notching all my disks with a single hole punch. I was so nervous doing it. Saved me having to beg and convince my non tech parents that I needed another box of floppy disks. Birthdays and Christmas never came around fast enough.

Yes, the problem with all of the MOS NMOS chips is the passivation layer. It has too much boron in the glass. Over time the boron migrates into the chip substrate poisoning the transistor junctions.

Arrrgh, you smooth toned geek! 04.30 here in NZ, off to bed but clicked a refresh! All the best from your Oceanic listeners!

I seem to recall a video by Jan Beta, who works a lot on PAL systems (being German), and he had a board he was able to buy and install that had, if I recall, 3 different pots that could be adjusted to get rid of the jail bars issue.

Another working machine and much useful information. The holepuncher warmed my heart ... so reminiscent. Greetings from Germany.

if you have a scope, you could set the background color to grey and look at the video signal on the scope with trigger on the h-sync and make the signal bigger in ac-mode. on channel 2 you could look for other signals around the vic-II that looks similar to the jailbar-noise in the video signal. that would be super cool

When using a Floppy Head cleaner in a single sided floppy drive, you should not use one made to clean a double sided head. The spinning disk cleaner is rubbing on the felt head clamp. SCOTCH made floppy drive cleaners with a punch out on the topside of the cleaner disk that is left in place for single sided drives. One cheat you can do is to cut part of a tyvek sleave and make a patch to cover the topside opening so that the felt pad slides over the tyvek patch you have made. This will save and prolong the felt pad clamp.

The Tandy CoCo series used MFM drives, and how I notched them as a kid is just used a hole punch on the edge of the disk, and they slipped the hole punch inside punched the sleeve on both sides individually. Originally we would cut the disk open, mull the media out and punch them, but were eventually able to do it safely with the lift and punch method. When I first got a 3.5" 1.44MB computer I started drilling my old 720k 3.5" disks from my 1000HX and reformatted them to 1.44.

Welcome to the basement where we tinker with Commodores and other ancient computers to allow them to continue their lives.

A lot of really good info in the video. Nice to see the VIC-II issue illustrated the NTSC C128 to help someone that has that problem. Also, nice background on the disk drive and info on the EEPROM/RAM for JiffyDOS. Oh, and I've seen "Competition" joysticks in that color scheme on eBay, so I guess it's good to know that they may not be worth buying (maybe some of the black ones are bad knockoffs, too)

Just cleaned and tested a 1541 I purchased and it seems to be fine. Now I got to watch a new ADB video, what an excellent day!

I used a 3-hole punch we had laying around the house and adjusted it so the hole was where I wanted it. I also punched the other side as the 'round' hole didn't catch as much on the disk sleeves. I thought I was really cool.

22:55 An ISMET made C128 power supply. They also made some of the Amiga power supplies as well.Usually the joints around the transformer crack but this one has obviously smoked its pass transistor ! Those "FRAKO" capacitors love to go bad. Their Amiga power supplies were junk also

I put in a write protect bypass switch on my 1541 drives. You use DT switch and replace the light sensor with the switch so in one position it writes anything to either side and the other position everything is write protected i.e. sensor always on or always off. Worked good when working with new users so they couldn't accidently erase file or format your disks. In the other position you didn't need to notch the disks, also back then people wouldn't look on the backside of the disk if it wasn't notched so you could hide files in plain sight.

When I bought my C128 in 1985 those bars was there.

That half-width font looks remarkably like the Commodore PET font. Probably not a coincidence...

Germany was and still is quite the Commodore country. I grew up in the 90's but even I used to play on the C64 and Plus4 myself, had a 128 later on and stuff. It's pretty great you get all these machines working again, it's always sad seeing these things going to trash.

The Y and Z switching is because is the German standard, you can also see that you typed the eszett (ß) too, maybe use smaller characters to fit the extra German letters in the rom?

16:12 The Serial Shift IO lines from one of the CIA chips was repurposed on the 128 for burst mode on 1570/71/81 drives. This means the loopback on the harness from Serial shift CIA 1 to CIA 2 will not work properly.

Personally I would recommend against using one of those cleaning floppies in a single sided drive like that. The cleaning disk is slightly rough and so is mildly abrasive, and over time will wear down the felt load pad on the drive head, the pad on the spring loaded side that presses the disk to the head. If it wears down it can’t press on the disk properly and it’ll look like the drive is going bad with read errors. While those pads look replaceable, they are impossible to find! It’s far better to use alcohol on a Q-tip. The cleaning disk should work fine on a double sided drive, though, since it’s rubbing on a head on both sides and there’s nothing to wear out.

1570 is the 1541 with faster Data Transfer on IEC-Bus in 128 Mode. Falls back to C64 Disk speed (or better say disk slow) in 64 Mode. Double sided fast speed came with 1571...

A couple of thoughts: I remember just using a hole puncher or a bread knife to make the second side. Also I distinctly remember times when a diskette stopped working for some reason we had a trick we used to try and that was to cut the upper/top part of the diskette 's "enclosure" and "take out" the disc+ flip it, making side A side B. I don't know why, but some(not very often) times that made it work again. You mentioned your "joystick"(not the fake competition pro), but the other one with a black D-pad and two red A+B buttons and I can't recall ever seeing that one for the C64 or the 128🤭🤣. Awesome video 👏😄

My notch puncher was home made and used a wood template and one of those metal nibbling tools. Did an awesome job.

Looking great! Always enjoy your videos! Would love to see a video on c128 versus c64 cartridge incompatibilities.

Adrian, that "single-pixel width font" is the Commodore PET font. Boot up your Commodore PET side by side and they will look identical.

Everything I've ever read about Jack Tramiel said he was cheap as, and would find ways to reuse everything from calculator keys on the PET, to various C64 motherboards vs cases, etc. It's been amusing to watch you run across so many different variations over time. This drive is especially interesting, because the amount of manual labor involved must have cost more than the PCBs did, even considering PCB costs at the time. Even if Tramiel wasn't involved with this drive decision, it's clear the culture was set :P

I've seen strong jailbars like that on PAL C128s. On one, I fitted a board that was supposed to help reduce them, but no amount of adjustments improved it.

Really cool having a German/Pal 128 and 64!! Congrats on troubleshooting them and getting them working... Too bad about the poor video on the 128!

Adrian, I loved it! I have a new video, releasing tomorrow morning, about upgrading the 1541-II power supply to SMPS, modern 5V and 12V supplies. Thanks for all your hard work and entertaining content!

The 220 transformer is actually 2 * 110 in serial if you put them in parallel you'll get 1x110.

Those disk notchers also worked with drives for the BBC Micro. I remember when I first learned u could do that, it was a revelation!

That alternate font looks to be very similar, if not identical to the VIC20/PET font.

Got hooked on German Haribo after getting a large bag with my Prusa 3D printer. Luckily you can find German Haribo in large packs on Amazon.

The vertical bars are quite prominent in both of my flat C128 and my C128D. The German versions of the C128 use the QWERTZ layout, hence it switches between Z and Y when you press that key.

128s are pretty much bullet proof. Except the ones with the "MT" Ram chips. In most of my repairs these were the issue. Very nice to see something different :D

nice QWERTZ to QWERTY switch :D

To test the burst mode in the 1570 just load a program in the C128 mode, all other commands sent on channel 15 to the drive using the regular C64 -style data transfer. Load/Save uses the handshake of the two involved 6526s.

The brown wire at 6:08 is normal on some C128 revisions (all 3 of mine have this), if you're looking closer on the cap above the color ram (chip right to the char-rom) you'll probably see a cut in a trace. Fun fact: there are 1571 drives out there, having a modified 1570 board inside. How can you tell? 1570 is written on the board. I have two of this drives.

Hey Adrian. I wanted to note a couple of things: 1. In my original C64 I had in the early 80s the power supply broke down. It was a fault in the 5v linear regulator. My dad figured it out. He actually drilled it out and replaced it with a new one. It worked forever after that repair, just like you mention in the video. I remember him being very sceptical about the repair. He was surprised it worked but it did. I think it still does. maybe I can find it and picture it for you, if you want. 2. I never had a C128. Not many of us Commodore fans did. However, a good friend of mine did have one. He had the cringy looking video output, just like you show in the video, since day one. I dont think it's a failure. I think it was shipped out of the factory looking like this. I remember it clearly, wondering why it was happening. maybe it is more distinct in PAL versions of the machine (I live in Israel, we have PAL over here). Please please please keep the Commodore content up and coming. it is addictive! I can't stop watching. Thank you for all the time and effort you put into filming the process of repairing these soulful machines. I noticed you never let any assumption go without checking it and cross checking it until you validate it is correct (like with the slow rise time of that c64 in part 1 of this video). I really appreciate your work. Cheers from Israel, Sephy.

A disk with double notches where named flippy disks.

What I did back in the day. Formatted 1/2 of the disk dos. Then flipped the disk over and formatted the other side apple II. So I have a what multiboot? I can't remember if I put ms-dos boot files on one side. But Anyway. I thought I was pretty smart at the time.

20:08 Oh boy, I remember those power bricks (called "Elefantenfuß" or "elephant foot" here in Germany ;) ). If they are at least a little bit similar to the C64 ones, they are prone to failure and even thus prone to damaging the Commodore because of overvolting it in the process. :(

The C64's door wedge PSU is a usual fix here in Germany: Just replace the old board with a fitting 5V AC-DC converter, like the NFM-15-5 and you have a reliable PSU in original design.

Yep, always good to salvage cables, was going to refurbish my old Amiga 500 PSU, but, parts of it were toasted (hot resistors resisting with futility) on the PCB, caps leaking and I'm just lazy, so harvested the in & out cables and am building a more compact PSU with a 60w 12v PSU from banggood & a knockoff PicoPSU inside a nice light grey PSU enclosure, should look the part when finished... :)

To make "flippies" we had to cut the protect notch and sector index hole both, and I would generally just use scissors and a ruler to mark where to cut the write protect notch, and for the sector hole again with the ruler to make where the hole should go, and a simple hole punch (remember to do both sides!) would do the trick. The problem with that was flipping the disk reversed the direction of the disk, and disks in those days had a white "fuzzy" dusk collection pad that sat on the disk and flipping the disk and reversing the direction would dump all the collected dust onto "side 1" often trashing the disk, so I stopped making flippies.

0:00 Well hello Adrian!

There were new produced warranty stickers that matches the original ones. That could explain how an Character-EEprom have found its way in the C128.

Just another awesome video!!

Gotta love exploding voltage regulators. I think that's the most violent one I've seen.

I don't know if it was required but I definitely hand-cut a notch and an index hole into my TRS-80 CoCo 2 disks.

The brown wire is for switching between character sets, the caps lock key is repurposed for switching between US-ASCII and localized (ÅÄÖÛé, etc). Edit: looks like you found that out on your own.

0:03 good way to start with an "up yours" 😏 ✌🏻

That PSU must have gone with a flash and a bang! LOL.

In the 1541, notching the disk meant having to put the Write protect tape label on it to prevent overwriting the disk. That was an issue because the label tended to come off and hang up in the drive mechanism. So i put a switch inline with the sensor so i could trick the drive into thinking the notch was covered.

Pure MEK works well for a lot, including the circuit boards as well.

Quite many have suggested LumaFix or similar mods for improving the picture quality. I have used LumaFix and ClearVideo64 and bypassed the RF modulator. The picture was great on Commodore 1084S, but quite bad with plasma and LCD TVs. Now I use c0pperdragon’s C64 component video mod with OSSC scaler and the picture is perfect using 4x line multiplication on a 1920x1200 monitor.

Cannot wait to watch!

Adrian, that transistor released his magic smoke lol

For mechanical keyboard sets at least, a lot of times the spacebar and other longer keys are made out of ABS instead of PBT, since PBT plastic warps more easily (which can be more noticeable for longer lengths). Maybe that has something to do with the uneven yellowing?

3:45 Perhaps this a very rare Dwarvish C-128?

This is weird, I made one 1570 from a 1541 case without knowing that Commodore already did it and I came out with the same adapter plate idea... but mine is two sided :-)

Back-in-the-day, using the back side of the disk wasn't 100% reliable. First, some disks failed QA on one side and if you used the back side would run into issues. This was a problem early on, but disk manufacturing quickly became good enough that bad sides were extremely rare. The other problem is, because flipping the disk caused it to spin in the other direction, it was possible that dirt and grime that had been pulled off the disk by the felt lining, could be pulled back out and run under the heads -- this would result in the need to clean the heads more often. But in general, flipping you disks gave you twice the value for your disk purchasing money -- and that was big because back-in-the-day disks were expensive. Thanks for the trip down memory lane.

adrian, as a motivational speaker, i have been introducing positive thoughts into the rainbow lobster harvesting community for a long time, they dont even know...my tenure of involvement is extensive & comprehensive...its for the lobsters adrian...the lobsters...

00:45 ... One thing I never liked about the C128 was how much desktop realestate it covered. I wish the case & board designers hovered the keyboard more above the pcb. This would in effect reduce the depth measurement (length front to back) by about 3-4 inches, I think, thus the only thing keeping it from getting more shorter is the pcb. But I'm sure there was a reason to pancake out the square footage to what the C128 had become, besides thermal dissipation factors. 11:55 ... Have you tried a component cooler spray on the Vic-II chips when turned on to see if cold temperature affects the video output? 15:25 ... I have always preferred single pixel width characters on my C64. I designed new characters that way & uploaded them into ram to replace the original character rom, just to see how they looked. That was in the mid-late 1980's. I wanted to make my own replacement char ROM chip then but didn't know how or was too busy with other things. To me, the thinner characters looked more professional too. 24:45 ... What could have killed that regulator? A power surge, such as lightning? 43:33 ... Yup, I still also have my disk notcher, bought in the mid 1980's. Of course, not every uni-sided floppy disk had a reliable 2nd side due to factory quality check, since most likely the 2nd side was never meant to be used. The same was true for 3.5" floppies, but it was more about density, not sides. Still, for the most part, probably 90% (my guess) of all 5.25" disks in its heyday had good 2nd sides. And back then, I had also sometimes confused this disk notcher with the Suncom C64 Icontroller joystick because they almost look alike.

Great video, Adrian! Write protect notches... Maybe more appropriately "write-enable" notches. I remember when little kid me was introduced to those without a full explanation of how they work, so my 6-or-7-year old brain put together this idea that the notch in the disk was how the data literally flowed into disk to be saved... If you covered the hole it prevented the data from getting "inside" and on to the disk. Maybe covering it with medical gauze will keep computer viruses from spreading? Very cool about the ASCII/DIN key... I noticed that this gives you access to umlauts and other characters that make spelling in languages-other-than-English possible. Unless I'm overlooking it, I don't think I've ever seen you do a video covering the Commodore 1701/1702 monitors? Would love to see you go through one of those units... When you pair up a good C64 with a good 1702, it's pure heaven.

You could compare the differe t video signals between the different chips with your scope. Possible this can be a slight variation in the raise and fall times of the video signal. If I remember correctly I saw a video comparing different versions of the video chip regarding jailbars.

Caution on using a hole punch or tool to notch the other side of a single-sided disk... After ~ 25 or 30 years, I converted my old C64 disks to PC ".d64" files, and found MANY second sides failed to copy properly. I'm led to believe the single-sided disks started out as double-sided, but failed quality standards and were therefore not certified as double-sided. FYI, I built a cable and had PC software to connect my 5-pin DIN serial cable to a PC parallel port, which is how I performed the transfers.

The video is normal for PAL. Normally if used on a CRT the persistence of the phosphor and the bandwidth of the video circuitry in the monitor would smooth out the display. (still noticeable). The problem with converting to LCD for all retro computers is that the level steps in the colour ADC's are too fine thus it digitizes the noise. The retro converter would work better if they used less bits in the ADC or they bin the samples and normalize them (a bit like auto-tune for colours)

28:43 The CIA in the 1570/71 is only there for the Serial Shift ability. I believe it is also a 2MHz chip, so you could put it in the 128, but not vice-versa.

There was a time I had at least one of everything Commodore ever sold. Kept it for years. Finally chucked it all into the dumpster. Free at last.

That CompetitionPro doesn't look fake. The clear one was the 3nd model that was released, when there only had been the previous two black models (first with metal leaf contacts instead of microswitches even on all directions and a black handle, 2nd black with a red handle, with microswitches only at the directional contacts, 3rd one with microswitches only at directions but not in the fire buttons, red handle and transparent case), still using the rubber ring instead of springs and it was the 2nd most popular. It was about 3 years later, that they switched to springs instead of rubber, first seen with the (originally dark blue) CompetitionPro-Star and then later with all models. Amongst sophisticates the rubber-ring ones with leaf-contact fire buttons where the best CompetitionPros ever made because you could control way more precise and sensitive and much faster than with the way too stiff spring loaded models and they also didn't bother you with that super annoying clicking so extremely as their still where leaf-contacts in the fire buttons. Also you could fine tune the fire buttons' leaf contacts so that even slightly blowing at the button would result in a registered push. The possible fire rate was MUCH higher than with the microswitched fire buttons of the later models, because the microswitches didn't return the fire button fast enough. You can tell later of the terrible clicky and unprecise black models from the better and older ones by the clicky ones having a visible stamping on the joystick's upper edges, where the CompetitionPro would usually have had it's small xtra fire buttons, as they obviously used the same mold. But sadly not all of the clicky models have this 'feature', as they probably used some remaining older cases after switching to the fully-microswitched-spring design. I can still remember the gaming magazines reviewing the CompetitionPro after these changes. they all praised it to heaven and claimed the microswitches being so great, and how they wished that even their wife had microswitches on her body - I think this was a bit weird, as no one that I knew of (including myself) actually liked the newer ones better than the older ones, and when we did mixed 1:1 matches for testing, the newer sticks' design clearly proved to be a disadvantage. Also a metal spring being cheaper than a massive lump of rubber seemed to be the main reason behind the change.. Problem is, that the rubber didn't age well, since. That's why I prefer the ZipStick nowadays, as it had a spring but isn't as notchy as the spring using CompetitionPros.

14:10 welp now I feel old :p can't hear a thing. Love this series, especially how you just dive right into fixing stuff!

WOOHOO! We need an 8-bit dance party!!

Thanks for sharing this pic.

Instead of using 9VAC for the power supply, you should be able to use 12VDC. 9 x 1.414 = 12.73, so probably close enough. You have to get polarity correct if it doesn't feed a full bridge rectifier

31:00 Ditch the stupidly hot internal transformer and regulators. Install a 4pin DIN socket and use a 1541-II power supply.

Very good thanks 👍😎

Have you tried adding extra capacitance to the VIC chips that are bad? Some PC Engines have a similar problem but it can be fixed by adding an extra cap to the video chip.

I notice the keyboard buttons return and restore become less yellow, but weird, maybe those keys are made of a different alloy plastic. I myself have been a plastic processor for 24 years, so that some things remain a mystery. Like your video's Greetz

My guess is that different letters were made in separate batches with different amounts of bromine in the plastics

Did you notice @ 8:14 it only said 30719 bytes free, not 38911?

If you connect a 220V transformer to 110V, you simply get out 4.5V instead of 9V. The transformer has two 9V outputs, one connected directly to 9V pins, the other to the 5V regulator. As you would replace the 5V part by an switching power supply anyway, the second 9V output is free. So why not simply put both 9V outputs in serial? So on 110V input you get 2*4.5=9V, exactly what you need. So you can reuse the transformer...

2:20 "I expect this thing to work perfectly" Wonderful sentence, don't expect everything to work first try :D

So how do you like your transformer pc board, regular or extra crispy?

You should try recapping the voltage regulator in that power brick. It might only LOOK like it exploded. (Kidding, of course.)

i wonder why COMMODORE INC did not make a duel disc which one high torque motor driving both drives via a shaft and two drive belts.

The Z to Y remapping is part of the german QWERTZ keyboard layout. It swaps around Z and Y and also adds 'umlaute'. ä ö ü

german letters character rom... from factory. nice!

i didnt know the command "New" thanks :-)

Commodore filter the supply to the VIC to reduce digital noise on the video output. On this schematic (probably not the right version) the most likely failure is C63. See: www.zimmers.net/anonftp/pub/cbm/schematics/computers/c128/310378-2-right.gif C62 performs a similar function for the colour generator. Try holding a good capacitor across the suspect ones to verify this. Low ESR types are best. The value isn't critical. Edit: for the digital RGB output, try C88 and C61. All of these capacitors are 10 uF, so testing and potential replacement should be straightforward.

Get a empty tin that doesn't have anything in it fill it with Acetone and dunk the potted module in it and leave it for five days and the potting compound should be more or less in solution and the unit can be removed.

Your character rom is fine, you just have the Dwarven language version of the C128.

Methinks there's a way to de-pot that compound. I don't think anyone wants to bake it out. Takes a while and stinks. Those disk notchers also worked for Atari 8-bit drives like the 1050. Rather irked you forget Atari.

Would a similar fix to the 128k speccy jail bars fix be effective? By changing the smoothing disc caps to a different rating?

Have you tried adjusting the trimmer capacitor next to the clock chip ? It's possible that theres some process variation in the clocks that the VIC generates that could be trimmed out with this

15:15 That button works in C64 mode too...

25:30 The back grille part of that drive looks like your camera is focusing and defocusing on it. Or something. On my 4k smart TV it looks like its rainbowing through various colors.

42:20 .. from what I knew about Commodores "manufacturing philosophy" it wouldn't be surprising AT ALL if the case parts were already different right from the factory.

I really enjoy your videos and watch the consumer trail of computing. But some times I feel like I am at the end of the Calvin Coolidge administration (1923-1929) and watching someone show their collection of buggy whips, wagon wheels and horse harnesses.

That 6526 A is just a regular 6526 CIA with the minor difference of being 2 MHz capable.