Apples and Unicorns: A sudden rush of RetroComputing (Repost)

(Originally posted on LinkedIn Jun. 24, 2020)

Retrocomputing is a funny hobby. When you’re dealing with computers that are 20+ years old, most things tend to plod along at a stately pace. Maybe a new upgrade here. Maybe a new purchase there…

And then there are periods like that since my last post, where over the period of a fortnight I gained several new systems in a rush.

A Bunch of Apples

First up, as I have posted before, my Apple IIeuroplus is not a happy piece of fruit. I’d described changing the RAM, but I was despairing. I’d planned to use the Cassette port and use the rather nifty site here to download some diags disks, but it wasn’t even reliable enough to do that. I’d decided there was nothing more to do, so I packed it all away and got on with my life.

Then, almost out of the blue, the person who gave me my initial Apple II mentioned they knew of someone potentially interested in divesting themselves of an Apple IIe, the enhanced model of the Apple II. Was I interested? Ooh yes please!

I reached out to the individual with the Apple IIe, and offered to either pay or swap for a Commodore 64. They got back to me quite quickly and said that as they had got the Apple IIe for free, they didn’t want anything for it. It had been sitting idle for ten years and they wanted the space back. Oh, and did I want a couple of untested Apple II clones as well?

I was gobsmacked by this super nice offer! I took them up on it and arranged to collect the systems.

And then a Unicorn appeared…

In the context of collecting, a Unicorn is any super rare item. So rare that they may as well not exist. An item that, if you want one, you better be prepared to pay.

In my eBay “Saved Searches”, a super rare computer I really wanted appeared, and it was at a reasonable starting bid! This was the fabled “Dick Smith Wizzard” AKA the Creativision. I’d only seen two come up in 3 years of watching, and one of those was a $1500 “complete collection, in box” that I just couldn’t justify. I carefully put in a bid, with a maximum bid of $251.50, the odd amount being slightly over a $50 mark, as many people stop bidding at multiples of $50. I was the front runner at $199!

And that’s where it sat for the first four days of the 7 day auction. I was hopeful that maybe this time I’d get the prize, but I didn’t want to get my hopes up as surely I wasn’t the only hunter after this particular prize. Sure enough, with 3 days to go a rush of bids appeared and the price shot up to $210, then $250, where it sat for a few hours, and then a flurry up to well over $350. This was more than I could easily justify for a system with only a handful of games, even if I did have an emotional attachment to the system. Dejectedly I shut down eBay and mentally “walked away”. Some lucky hunter would get the prize and be happy. I consoled myself with the thought that in the next day I’d be getting some Apple IIs.

Collecting the Apples

At the arranged time I drove out to meet the collector. We chatted for a good half hour about all sorts of things in the domain of collecting old systems. They were primarily a Mac collector, and had got the Apples as an “Adjacent” system, rather than as part of their primary collection, thus their preparedness to give them up to gain space. It turns out that I knew the original owner of the systems, in a very “Perth” kind of way.

The haul included a CRT Greenscreen monitor, a DuoDisk twin 5ΒΌ” Drive and the three systems. I thanked them again, loaded up my car, promised to keep them in the loop on the status as I looked at the systems and headed home, as I had a meeting coming up.

I got home, unloaded the car and joined my wife on the couch to attend the meeting. (It was a video-conference)

About three-quarters of the way through the meeting I was idly checking my phone when I got a message from eBay. The subject line was “eBay Bid Change Notice”…

The Hunt Rejoined

I blinked, and carefully read the e-mail. “…The following item, on which you placed a bid has had a bid retraction or cancellation, and you are now the high bidder.”

Wait, what? I was the highest bidder again? Whoa! I nearly cried. I showed my wife who was suitably amused. Later that evening I got outbid again, but only by a slim margin.

Meanwhile I had cleaned up the first of the Apples (the IIe), inspected the power supply for correct voltages, and got it to boot to a prompt. An excellent start. I carefully added in a Floppy Disk card and Drive. It was now booting from floppy disks. I ran the onboard diagnostics and it passed all tests. Exciting! These tests also revealed that the IIe had a memory / 80 column card upgrade in place already. Nice!

I also inspected the two “Clone” Apples. (One of them had a handwritten note identifying it as an “Orange”, and sure enough, where there would normally be an Apple Key, there was a round Orange Key instead). One turned out to be a clone of the Apple IIe and the other a clone of the older AppleII+. Unfortunately there were no ROMs in the sockets of the II+ clone.

Moving back to the genuine IIe, my next step was to see if the serial card that had given me such problems on the II+ would work at all. If it DID work I would be able to use a serial link to read disks off my PC. In it went, no errors, no problems. This was looking really good! Next step was to get the transfer software over onto the Apple. This was one of those classic “Chicken and Egg” problems where if I had the disk, I could make more disks, but I’d need the disk to make the disk… or did I? Remember that useful site at the top of the article? I had seen people mention that they’d found it the most reliable way to get the needed first disk. What did I have to lose.

I grabbed my trusty iPad, found an audio lead and plugged it into the Cassette port at the back of the Apple II. I stuck a blank disk into the disk drive. I booted the Apple into it’s BASIC command line from the onboard ROMs and told it to “load” from tape. On the iPad I then played back the carefully constructed WAV file at full volume. It picked it up and proceeded to load a preloader! This preloader then formatted the floppy disk and copied over the rest of the disk image to the floppy. Was it that easy?

Why yes it was, and also fast. As someone used to the infamous C64 serial based floppy disk drives, the Apple II Disk is lightning fast. I booted off the freshly minted disk and it worked! Now what? My next obstacle involved me fossicking through my box-o-cables until I found a long USB cable. (Thanks past me for saving that 5M USB2 AtoB cable). I then dug out my USB Serial port and plugged it in. There was a bit of excitement when the server part of the software decided it didn’t like the serial port, but a reboot fixed that in short order. The next order of business was a simple one, but threatened to derail the project. I needed a 9 pin to 25 pin serial adapter. After a thorough look through my collection, I asked my housemate if he had one. He did! It was still plugged into a modem. πŸ™‚

I had communications! The two systems were talking despite the 25 year difference in age between them. However, my initial attempts to transfer data all failed. There was one final obstacle would not be solved to the next day.

Meanwhile…

I had now been outbid on the precious “unicorn” system. I knew I could afford a bit more but didn’t want to push it too hard. The auction was due to finish the next day at 1:30pm. I decided to sleep on it and see if I still wanted the system in the morning. My wife was supportive (She puts up with SO MUCH) and when I got to work in the morning I had decided to up my bid to $327.50 and to leave it there. I’d either get the system or I wouldn’t. I put my bid in and the price jumped up to $311. I was still in the game. I spent a nervous day, occasionally checking eBay but otherwise trying not to get too excited. With an hour to go I decided to “cold turkey” out of eBay and just see what happened. All the excitement was infectious and I found myself working on my real work much more intensely than usual. And then… “You Won!” came through my e-mail. I had got it for $311. That evening I arranged to pay for the system, and the seller contacted me to say he’d ship it Wednesday morning. I haven’t yet received it, but I’ve already started researching what else I can do to improve the system.

Back to the Apples

Now I had the “unicorn” under control and corralled, I could get back to my Apple computers. That night I started playing around with my newly created Serial Link setup. Initially I thought it was related to the sources of media that I’d found, but then I realised it was my media. It turns out that a good percentage of 30+ year old disks are going to be unreadable. Finding some unused disks in my collection, I tried again and I had successfully imaged across a game that I wanted to try on the Apple.

Great! My game boots! I can play! Only one problem. It was all black and white. So I tried it with a different monitor (A Commodore 1901 CRT, designed for my Commodore C128D) and it was still black and white. I then tried it with an Apple Colour monitor. Colour! But why is the blue showing as pink and the red showing as green? It’s not like I’m splitting out the colour as RGB… That monitor started failing about that point so I put it aside for another day. (I hate working on CRTs. I have been working on them since the early 90s and I still hate them. So many ways they can fail in spectacular and antisocial ways. Even with the “right” tools like a proper discharge strap I just don’t wanna!). I also tried a Composite to HDMI adapter and only got black and white. Anyway it was time for bed so I put it aside for another day.

The next evening I had another window of time, so I decided I wanted to the bottom of my colour issue. Jumping on my usual Apple II forum, I did some searching to see if anyone else had hit a similar issue. Almost immediately I found a post of someone with a similar problem. Scrolling through pages of in-depth technical discussions on the differences between PAL and NTSC systems, timings, Capacitor values and other minutiae, I finally reached the bottom of the article. The original poster hadn’t solved their problem, but a year or so later a different poster had added “I fixed my colour problem by switching the switch on the motherboard from “mono” to “color”. Wait, what?

Sure enough, opening up the case and looking at the board revealed a tiny switch on the right hand side of the board labelled “mono/color” and it was in the “mono” position. Several minutes of swearing followed. A flick of the switch and I had colour in my games.

This was about the point (in between forum searches) where I also checked out the voltages on the clone IIe (Henceforth referred to as the Orange) to see if I could get anything out of it. Voltages checked out fine. I plugged it all in, turned it on. It beeped but no picture displayed. I re-seated all the obvious chips and tried again. Still got a beep then nothing. Oh well. It had been given to me as “not working” so that was fine. I figured I’d look at it later. Shortly afterwards I plugged the Apple IIe in to the same setup and also didn’t get a picture. Waitaminit. Sure enough the OTHER end of the video cable had come unplugged with all my video testing. Plugging it back in and testing again, my Orange IIe booted to the command prompt. Huzzah!

The Future

At this point I’m quite happy with the Apple IIe and Orange IIe that I have. I don’t have enough parts to add a Floppy drive to the Orange IIe yet, but once I’ve tested the cards from the Apple in the Orange, replacement cards are actually not too hard to come by. I also need to see if the ROMs from my Apple IIeuroplus work in the Clone II+. Maybe between the two I’ll be able to get a II+ working. There’s also a project afoot to make a replacement ROM set for the II / II+ family that would help get the system back on it’s feet.

Long term, the Apple II is very expandable. Upgrades I’d like to get in the coming years include a soundcard, a virtual Floppy Disk and a Z80 card so I can run CP/M. With the prices though, it’ll be a slow process.

As for my new “unicorn”, I think I’ll investigate a Composite mod for it, as well as some other “homebrew” kit. Options include a tape interface and some sort of “universal” cartridge.

Reocomputing: Two Steps Forward, One Step Back (Repost)

(Originally posted on LinkedIn Jun. 15, 2020)

Retrocomputing continues to help me find my happy places.

I’ve been extensively working on new things. I recently rebuilt the area all my consoles live, to simplify things, going from having to use four different remotes in various combinations, down to two, one of which is only used to turn on the telly.

Currently I have seven different devices plugged in, all using different connection technologies, all needing to be scaled. It’s a nightmare of cables and adaptors but I got there in the end and now it all just works.

I also finally “emptied” a project box by finally fixing one of my retro computers. I now have a working C128D. It had stopped working a while ago, with the PSU tripping under load. After a lot of research, trawling through forums and finally asking someone to break out a multimeter and measure some resistances, I was confident the issue was with the PSU. A complete rebuild later and it’s happily booting! There’s a couple of minor issues I want to resolve with the disk drive, and I want to heatsink the custom chips but I’m generally very happy with it. Can’t wait to fire up some of the more obscure titles that could take advantage of the extra processing power over the C64.

As for the Apple II, it still isn’t working any better. I need to get it back on the bench. I’ve had someone suggest a rather clever website that plays back audio files that I can then play directly into the Apple II tape port, which will then (hopefully) write out a disk for me.

The Apple II forums I hang out in suggest I should probably just abandon my current model, due to all the limitations it has, and get a newer model. Unfortunately that’s not cheap, particularly as they’re not well represented in Australia, so I’d most likely need to import one from the US, easily doubling my costs through import duties and shipping.

I’ll keep that as a backup option. Until then I’ll keep slogging on with this one. The price (free) was certainly not something I could argue with.

I’ve started thinking more about my “next” purchase too. I’ve managed to secure an Atari 800XL, a lovely 8 bit machine designed by engineers who went on to design the Amiga. Unfortunately it and the BBC Master system are stuck in the UK by Covid 19, as the people who were going to bring them back to me have been under isolation for several months now. I think I might just have to “bite the bullet” and get them to ship them to me.

I’m thinking about getting an Amstrad CPC system, most likely the CPC6128, as it’s a nice sweet spot of compatibility and power.

After that it gets more difficult to choose. I do have a wish list, but some of the remaining systems are tricky to source at the best of times. I’d love to add an Acorn Archimedes of some sort. A Microbee would be a lovely Australian system to have, but I suspect the next thing I’ll actually get is a Harlequin 128.

I still need to get my NES working, so I will need to order a proper edge connector for mine, as I’m 99% sure that’s the issue. I have located an improved edge connector, but once shipping is factored in, I’m going to have to save for this one. I’ll get there, just not this month.

Continuing Adventures in RetroComputing (Repost)

(Originally posted on LinkedIn May 18th, 2020)

Based on a picture from WikiMedia: https://commons.wikimedia.org/wiki/File:Apple_II_Plus_Inside_Microsoft_80_Column_Card_Closeup.JPG

As I have posted here before, my current hobby is fixing up old computers. Some of this involves working with components and tools not easily available at your local walk-in electronics store. Some of these can be covered by the “usual suspects” such as RS Components and Element 14, (My preferred suppliers) but some of these can only be purchased from obscure suppliers, often in China.

As you can imagine, recent global events have slowed the supply chain down dramatically, but things are finally starting to trickle through.

As a result, I was finally able to tackle my Apple II+ recently, having finally received my 4116 DRAM chips. The Apple II used 3 banks of 8 of these to generate the first 48KB of memory, with an additional bank of 8 on a “Language Card” (So called because they were needed to run additional languages such as PASCAL) to bring it up to a compliment of 64KB.

The whole point of this was to get the whole shebang ready to run a serial link back to a PC so I can copy across floppy disk images.

Unfortunately I still have an intermittent issue with memory corruption, and it’s really annoying. I am in a “chicken and egg” situation insomuch that, if I had a working system, I could get diagnostic disks made which would help me to resolve the issue, but as my system doesn’t work, I can’t get the disks, which means I can’t find the problem…

(Insert joke about holes in bitbuckets)

I’m not giving up, however. My current plan is to pull it all out of the case and check key busses with an oscilloscope. See if I can isolate out where things are “going bad. I’m also tempted to get a EPROM programmer, as many of them will also test 74 series logic. I may also see if someone on the various Apple forums are willing to burn me a couple of Diagnostics disks.

If that fails, I might just have to buy another Apple II to use to help me fix this one!

Here’s a list of what’s already been found and fixed:

  1. Many chips with significant oxidation on the legs. They looked like they had been steeped in strong tea with a browny black patina. Cleaned with a sand eraser and their sockets cleaned with electronic contact cleaner. This improved things a lot, and got me to the point where it’s semi-stable.
  2. Custom cable constructed to connect from the Floppy controller to the Floppy drive. I had to customise both the cable and a connector. Apple used a 19(!) pin D connector, which I worked around by getting a 25 pin connector and pulling 6 pins out with pliers.
  3. On the Language card, replaced ALL the 74 series logic chips with new ones. Also replaced the ribbon connector between the card and the motherboard. This was, once again, a custom made part.
  4. Identified and replaced all 4116 memory chips. I believe all the ones I was using are good components as I “swap tested” them, but it was cheap to swap out all of them, so now they’re identical. I did find several bad ones.

Retrocomputing News (Repost)

(Originally posted on LinkedIn Feb. 6th, 2020)

(Image from Wikimedia, used under a CC license - https://commons.wikimedia.org/wiki/File:Acorn_BBC_Master_Series.jpg)
(Image from Wikimedia, used under a CC license – https://commons.wikimedia.org/wiki/File:Acorn_BBC_Master_Series.jpg)

Well, I continue to collect old computers and consoles. It’s a fun hobby and exercises skills I don’t get to use at work as much any more.

The pleasure of starting with a beat up old system and getting it working properly is a real buzz, and lets me practice both practical skills (Such as soldering) and analytical skills (Such as fault finding).

Currently the collection is getting along nicely.

I have the following computers:

  1. A Commodore Vic 20 (5k RAM, 1MHz 6502)
  2. A Sinclair Spectrum (48k RAM, 4MHz Z80)
  3. An Apple II europlus (48k upgraded to 64k, 1MHz 6502) – I have replacement RAM on order for this beastie. Until then it tends to “barf” whenever I try to load a disk needing more than 32k.
  4. 4 x Commodore 64 (64k RAM, 1MHz 6502) + an assortment of peripherals, such as disk drives, printers and such
  5. A Commodore 128D (128k RAM, 2MHz 8502, 4MHz Z80, Integrated FDD) – Sadly this machine needs more work as the power supply trips when I turn it on
  6. A BBC Master System (128k RAM, 2MHz 65SC12) – This is so new, it’s still on it’s way to me
  7. An Atari 1040 STfm (1M RAM, 7MHz 68000) – Upgraded with a Gotek Floppy disk emulator, a nifty gadget that allows you to use a USB stick to pretend to be a floppy drive.
  8. A Commodore Amiga 1200 (2M RAM, 14MHz 68EC020, AGA Graphics) – This one is waiting for me to get a chance to laser cut the case. I have extensively customised this one, as it had been “hacked” before I got it. This taught me a lot about circuit board design as I designed and ordered my first commercially manufactured PCBs for this system. This also has a Gotek.

I am also building up some “classic” consoles too:

  1. 2 x Nintendo Entertainment Systems – Neither work currently but I know why. I just need to actually buy the part to fix it.
  2. A Sega Megadrive – I’ve been trying to get decent RGB Video out on this for MONTHS, but it’s manage to elude me so far. I’m not giving up yet though. A new week, a new version of an RGB cable.
  3. A Commodore Amiga CD32 – Oddly this one can be very easily upgraded to be a full blown computer comparable to the Amiga 1200 above. So far I’ve resisted the urge.
  4. A Sony Playstation 2 “Phat” with an added hard disk and network card.
  5. An original XBox. (Dear Microsoft, calling your THIRD XBox console the “XBox One” was a dick move. Seriously. Do you know how hard it makes getting info about the original?)
  6. 2 x Nintendo 64. Mmm. Tetrisphere was such a masterpiece.
  7. A Nintendo Wii. The optical drive has died so I use an external HDD instead. Much more convenient.
  8. An XBox 360. Eh. It was cheap.
  9. A Playstation 3. I bought this new. It was shiney when I got it. A particularly nasty weekend doing far too much overtime payed for it.
  10. A Wii U. Kids got it as a Christmas present, when they were no longer very new. I like Breath of the Wild on it.

I also have a Raspberry Pi setup as an emulator to cover those systems I haven’t yet collected. If you are only casually interested in the old systems, these come highly recommended!

Once I have the Beeb, there’s not too many “must have” systems on my wish list, not counting the occasional “Unicorn” system out there that I’m unlikely to ever get.

I still want to get an 8 Bit Atari, such as the Atari 800XL, and I am actively searching for a Microbee, either in kit form or an original. (These were used in Australian schools in the 80s). I’m also likely to buy a Harlequin 128k kit (Emulating the later Spectrum 2+). Finally once I have all those I’ll probably start looking for an Amstrad CPC 128.

As for consoles, I’d like to add a Sega Dreamcast and a Super NES. However I keep my eyes open for the disturbingly rare Dick Smith Wizzard. (AKA the CreatiVision) The latter is definitely veering towards “Unicorn” status.

Quick retrocomputing update (Repost)

(Originally posted on Dreamwidth Feb. 3rd, 2020)

NES are still cranky.
Apple ][ has RAM on it’s way. It’s on a slow plane from China. I found a small machine-code memory test I could type in but it’s a pain to have to type it in each time so I plan to swap out banks at a time and isolate that way.
I made a ST to VGA cable and it works an absolute treat! So pretty!
I have ordered a BBC Master (the big brother of the BBC Micro), which gives me only two of the major 8 bit families to collect: The Amstrad CPC family and the Atari 800 family.

A boy can dream… πŸ™‚

RetroComputing adventures (Repost)

(Originally posted on Dreamwidth Jan. 8th, 2020)

Oh Hey! It’s been a while.
Just a quick update.
So:
Both my NES are now dead. Doesn’t seem to be the edge connector, although I’ll be buying a new one of those to make sure. I figure I should be able to get one or both working once I have a day to work on them.
I now have a MegaDrive. Still haven’t worked out how to get any decent video out of it. It shouldn’t be this hard! It supports RGB out of the box. I may have to bite the bullet and get an OSSC and a decent SCART lead for it. That does feel like a path that leads only to darkness.
I have an XBox 360. Not a bad bit of kit. Games are cheap.
I have upgraded my PlayStation2 to being a “Phat” and have added in a HDD and a network card. It needs some TLC but is nearly ready to redeploy.
One of the C64s has failed but in good news I’ve located a source of replacement power switches.
I’ve also purchased an Atari 1040STfm. It’s got a Gotek drive in it, so I’ve purchased the “upgrade” components so I can convert it to use a small screen and a rotary dial. They’re on their way.
Finally I have an Apple II europlus. Cranky computer! I’ve done a fair amount of work on it. It works some of the time but not all of the time. It’s quite feature complete, but I’m battling to get the reliability up to the point where I can start actually doing things with it, like, booting off a floppy disk. Unlike most of my systems that support some sort of diagnostics card / board / ROM, this model doesn’t seem to have any of that. I’ll keep working on it. Tempted to trade it up for a later model with better inbuilt stability.

Quick Post: I am feeling rather chuffed with myself. (Repost)

(Originally posted on Dreamwidth Jan. 10th, 2019)

So if you’ve been reading this a while you’ll know I bought 3 dead C64s. I managed to get one working by cleaning the power switch. (Cleaning the switch also got the next two working closer to full completion). The second one I got working by taking the RAM out of the third, which was showing symptoms much worse than the other two.

The third one was just sitting there, taunting me with a black screen and nothing else.

I did some research and it turns out the fault was likely to be one of 3 chips. Two of those chips were pretty reliable and also insanely expensive to replace, so I ordered the third chip (The PLA) on a whim and some new RAM. (Apparently, yes, you can buy new RAM for C64s. Who knew?)

All those parts arrived today.

I then took my “good” C64 (the middle one) and socketed it’s PLA. (I had already socketed the RAM chip). This allowed me to test the new components in a known good machine. The new parts all worked fine.

So I socketed up the third machine and tried the RAM and PLA in there. It worked first time!

So now I have FOUR working Commodore 64s. This is 4 more than I had this time last year πŸ˜€

(Big shoutout to Shrydar for allowing me to buy his old parts for an excellent price)

Even More Retro goodness (Repost)

(Originally posted on Dreamwidth Dec. 22nd, 2018)

So the Pi1541 arrived and I am amazed how useful it is. It’s not 100% compatible yet, but gets better every week. I LUFF it.
I’ve built the PSU for the 1541 floppy drive and that drive is currently formatting up disks in the background.
The C128D monitor is fixed, but I need to build a stand for it as otherwise I won’t have any desk at all. I also need to replace the failed switch with a working switch I just found.
I’ll need to order parts for the second 1541 PSU and C64 PSU. I’m really tempted to build a “pure” C64 PSU as per Greisis Workshop
After that it’s probably time to rejoin Artifactory, except for the small issue of their laser cutters being out of action AGAIN.

More retro goodness (Repost)

(Originally posted on Dreamwidth Dec. 7th, 2018)

Well, let’s see. I’m a LOT better at all this stuff. I have the A1200 booting, and more! It has:

  • A proper LCD monitor that supports the wonky frequencies the Amiga uses (15KHz vertical refresh).
  • An SD to HDD adapter, with an 8GB SD card in there pretending to be a couple of hard disks.
  • A keyboard adapter allowing me to use an old PS/2 keyboard with it.
  • A mouse adapter that I designed and made that allows me to automagically change to a joystick in the same port.
  • A Virtual Floppy drive (Works from USB thumbdrives full of disk images) that I flashed the firmware of and added all the extras such as
    • An OLED screen that shows me which image I’m using.
    • A pizeo speaker that simulates the buzzes and clicks of the original.
    • A rotary selector that makes disk choosing easy.
  • A design for a laser cut case to hold it all, only pending the Artifactory fixing their damned lasers again.

I also purchased a batch lot of Commodore stuff and now have:

  • A Commodore 64 (More on this later)
  • A Vic 20 (With a whole bunch of carts)
  • An SX64 with what appears to be a dead PSU
  • A Commodore 128D. This is a “Work in Progress” as it has a problem. I’ve recapped it but it fails when I plug the PSU back in. Basically I need to take it to the Artifactory and plug it into the bench PSU.
  • 2 Floppy drives, one of which definitely works, one of which needs some more love.
  • 2 Printers(!) that I’ll need to gove some love to once I have everything else under control
  • A C128 Monitor which has a loud scary crackle.

I had to build a new PSU for the C64 and Vic20 as the “stock” ones are notoriously bad. They have a nasty “fail to high voltage” that’s really efficient at cooking chips. This was an interesting challenge but I got there in the end. I’m always a bit squirrelley around AC voltage. 

I then purchased a job lot of dead Commodore stuff. 3 C64s and another FDD plus a joystick. This was for a fraction of the price I paid for the batch job above, but that was cos it was all failed stuff.

So initially I plugged all three C64s in one by one and documented the faults. Two had a problem where I got monitor sync and nothing else. One had zip. Nada. Nothing.
Doing standard fault finding I found the first two had no DC voltage and the second had no AC voltage. Turns out the switches on C64s have an effective lifespan of about 20 years… These were 1986 models. 
I had to desolder the switches, which turns out to be one of those understatement things like “And then the atomic bomb exploded” as Commodore must have hated their service technicians. There is an RF shield that’s soldered on to the motherboard. I manged to desolder the RF Shield through a combination of my soldering iron on maximum and using a set of dental picks as prys. Once THAT was off my desoldering station made quick work of the switches.
I desoldered, cleaned, greased and assembled and suddenly 2 of the 3 were booting! The third was now getting sync.
Of the two booting ones, one was perfect. It’s now in my stack of “working” gear waiting for a recapping. I’ll probably sell one of the working ones.
The other was showing rainbow garbage, an issue consistent with bad RAM. This led to more purchases.
I next purchased a couple of cartridges (Dead Test, 60 in 1) and some bits and pieces.

My next project was to build a pair of paddles for the C64. Unfortunately I haven’t had a chance to test them yet.

I used the Dead Test to confirm which chips were bad in the dead RAM c64 and I decided to use the OTHER dead c64 as a parts donor (As it was showing fatality on one of the key chips)

I have, however, been unable to desolder the RAM off my sacrifice board! I’ll try again this weekend if I can but it’s more challenging than I would have expected. After half an hour I’ve manged to get ONE of the chips to sit at a jaunty angle and that’s it.

Still to do:

  • I need to build a pair of 1541 ii PSUs. I have the parts for one but will need to order more bits.
  • I need to recap all of the c64s
  • I need to build more PSUs for c64s
  • I need to get to the Artifactory and test what’s wrong with the c128D and get it working!
  • I need to get my c128D monitor to the guy who has offered to have a look at it.

Stuff “in the mail”

  • Utility cart (Including Fastload, Freeze and loads more stuff)
  • Pi1541 (This is an awesome doodad you plug into a Raspberry Pi and it emulates a Floppy Drive.

World of Retro (Repost)

(Originally posted on Dreamwidth Jul. 11th, 2018)

What have I been up to? Well, a bit of this and a bit of that. Picked up a new hobby, BTW.

What’s that? You wanna know more about my new hobby? OK.

So after watching many YouTubers playing with classic computers I decided I wanted in. I’d recently acquired an Amiga CD32, which I got recapped (It was all SMT so I wasn’t going to do it I can tell you) so I had a foot in the door. I built a new PSU for it and I had a working console but I wanted MOAR!
At Swancon I asked around and a friend came to the party as she had a few more systems gathering dust. (I won’t name her to respect her privacy) This netted me an N64, a NES and, most interestingly a Sinclair ZX Spectrum.
Meanwhile I ordered an Amiga 1200 off AmiBay in a semi-working state (Don’t ask how much it cost. I’m mostly using it for parts.) which took three months to get here.
I have had some leave recently, so in a flurry I have:
Recapped the NES and the Spectrum
Purchased a new PSU for the Spectrum.
Replaced the cartridge connector on the NES <- At this point it was working.
Converted the Spectrum to use Composite out rather than TV Out. <- At this point the spectrum was booting.

The Spectrum needed much more work.
Although it was booting, the keyboard was unreliable. It was in an aftermarket case which meant I didn’t need to deal with the notorious membrane. This took me ages to fix as it was multiple issues overlapping. Firstly, all the contacts were corroded. This was solved with some contact cleaner, a bamboo chopstick (They make excellent “soft” contact cleaners) and some strips of cardboard. Secondly, some of the wires on the keyboard connectors had poor solder joints. I desoldered / resoldered them and that fixed that. I needed to also trim the edge of one of the connectors to ensure a better electrical connection with the motherboard. Now I could boot and type.
It took me a while to work out exactly HOW to load a game, and I didn’t have a tape deck in a working state. I solved this issue by using my Android phone, a piece of software called “TeeZiX”, and an eeevil custom made cable. Now I could even load games.
This is the point one of the key buttons on the keyboard stopped working. Thankfully I was able to resolve that with some contact cleaner.
I was loading games! I was even playing them! W00t!

My next step is to wait until next month so I can afford to buy another PSU to hack into the Amiga 1200. I think at this point I should be able to get it to boot to the “Insert Disk” screen (I hope). I’m not sure how I’m going to proceed from there to be honest. My big challenge will be getting bootdisks ready to boot the Amiga to the point where I can format and install an OS. The Amiga uses a non-standard floppy disk format (880K) that I may need to build a USB to FDD bridge just so I can write out the disks from images.

So that’s kept me busy.

Oh, and if you happen to have an old C64, C128, or an Amstrad CPC machine you no longer want / love, let me know πŸ™‚