Amiga 500 Plus with battery damage and an unexpected expansion

Not sure why I tested the low pass filter in my A500+, its got nothing to do with the chipset 😆 and while not shown here, I did soak test the board for a few hours and everything works as it should 😁

Great vid as always, One tip is to cut small sections of solder wick and hold it with tweezers whilst heating with soldering iron. Using solder wick while its still on the roll will soak up loads of heat from the iron and away from the joint.

Fantastic video Glen. The 385v cap in the PSU are typical for switch mode power supplies where the AC voltage is converted to DC. It allows for extra tolerance in the RMS voltage. Give that EU voltages are typically 230V AC + 10 % this would give us 253V AC. Once it goes through a FULL WAVE RECTIFIER 😅 it would give us approx 356V DC. The overhead is built in as some supplies do break the +10% limit especially in the UK. Decent power supplies typically use 400V caps but most cheaper ones for the EU market use the lower 385V ones since the voltage is typical 220V. I've measured 262V AC at home sometimes which used to pop old light bulbs.

Thanks for the video. I've learned a fair bit from watching how you do things using tools that aren't out of reach for us normal folks. I mentioned to you previously that i picked up a mac 128k and an a2000 to restore. You asked for an update so here goes. Mac 128k recap and retrobright complete. Works 95% (problem with the crt vertical circuit). A2000 is up and running, just waiting for upgrades to arrive so I can use it. Had a leaking battery but all the filth on the board seemed to have soaked up the majority of the goo. Thanks again for inspiration!

I love that you have Audacity running in the background capturing the audio... too much of YouTube is so overproduced nowadays.

I had no idea about cleaning with White Vinegar. I have a few RPC's (6 & 700's) that're suffering with battery leaks and I was tempted to just bin them but after this, they may have another life. The other bit about re-treating with common solder is another boon. Thanks for this and I owe you a pint.

Excellent video Glen.

Watched it picture in picture on the pc while working and posting this video on my dutch website. Great video :)

Thanks for sharing, I think I learned a lot about fixing the traces watching your video, now need to do it myself and fix the battery damage.

Great video. You were wondering about the Olivetti and Toshiba 3100 video modes. Well, during this time there were many standards about for more capable video modes than CGA. Olivetti had one such in their M24 series of computers and likewise Toshiba's 3100 laptop (pr maybe luggable) also had its own video type. It's interesting that the ATonce can emulate these because these were quite rare. Other such proprietary systems include Amstrad's PC1512 and the Plantronics card which was used in Commodore PC clones. David Murray aka The 8-Bit Guy did a video not that long ago about these Super CGA cards, well worth checking out. I think his game Planet X3 now supports most if not all of these graphics modes, and PETSCII Robots supports Plantronics, IIRC. Fascinating time for sure.

When you speed up your face it looks like you're raging and about to burst at someone! Nice work

I have the upgraded Plus version of the ATOnce for my A500 (main differences are a 14MHz 286, onboard 512KB of dedicated PC RAM, and a 287 FPU socket) and at the time in the early 90s I mostly used it for my highschool homework that required PC software not available on the Amiga like using AutoSketch for PCB layouts for electronics class and running the Turing programming language for CompSci class. You're right in your assumption that games are definitely not what these boards were designed for, the main issue is the emulation of the PCs video card is done in software on the Amiga side and the translation to the Amiga's video output is very slow. You definitely want to be using CGA or Hercules mode to get any kind of usable performance out of it and even then it's not really fast enough for action-oriented XT era games. Best you can get is about half the character rate of a stock XT in CGA mode and as you observed there are definitely some compatibility issues as well. You can just about run slow-paced games like the original Space Quest, Gold Box D&D games, etc but even there the slow video output is still pretty noticeable. The EGA and VGA modes are also mono 2-bit modes only so only really good for productivity apps (or running Windows 3.0 if you really want to punish yourself) even if you ignore how much slower they run. Something that does help (a bit) though is if you have some FastRAM in your Amiga as that will be allocated to the board first and does help performance a bit (although the video output still has to talk to CHIP RAM, obviously). Other things not touched on in this video is it does support using more RAM to not only provide the full 640KB for DOS but also 1MB+ memory like any 286 and also supports using the Amiga's mouse (with an included DOS driver), serial, and parallel ports from the PC side of things. HDD drive support can work in two modes, either with a dedicated PC partition / drive or using a hardfile on an Amiga partition. You can also use a RAM/RAD drive if you have enough memory in the Amiga as a small PC boot drive for faster DOS performance.

u have a great channel - i love it its a good channel as u explain in depth all about different systems thanks.........................

good video! you got lucky with that one, just one trace repair and some tinning to the other traces, I remember the last A500+ I did. Over a dozen trace repairs removal and replacement of the sockets for Paula Gary FatAgnus and the ROM. and most of the glue logic in the aria replaced. Got it going in the end tho. That was long before replacement PCB's where available, now id probably go that rout with one that bad.

Great repair job! Glad I’m not the only that struggles with desoldering gun. That vortex card is interesting

Nice Video! -Mark.

To clear holes conected to ground or Vcc I normaly just melt the solder and push a medical needle trough. Solder does not adhere to the steel of the needle.

nice job crg! its amazing to me that nothing was really wrong with the board after the leakege....cept the one broke trace...

That has to be one of the coolest Amiga pc compat mods. No side carts or anything. Awesome! :D

I once (AT-Once?) had a second-hand Vortex PC emulator expansion for the Atari ST, though I never got it to work. I'd actually bought the ST second-hand also, just for Oids, so that was consolation enough. From the looks of things, I didn't miss out on much with the PC emulator, and was very pleased with my first real PC, a Pentium 75 a few years later. (Even that's 30 years ago in 2025. I'm getting too old too fast; I wonder if I can soak myself in vinegar, IPA, and get recapped!)