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On building an A500++

Commodore Amiga 500 Plus

In the 1980s, Commodore made a newer version of their very popular Amiga 500, called the Amiga 500 Plus. It added a few things, namely newer versions of Kickstart and Workbench — both 2.04, 1MB of Chip RAM, and a motherboard-based Real Time Clock. The RTC was battery backed up, and is responsible for VARTA battery leaks. These batteries leak base (not acid, like most people assume) and this eats the PCB causing failures. There were also minor improvements of the custom chip sets, introducing the Enhanced Chip Set.

Enter the A500++

The A500++ is a newly designed circuit board that is a direct copy of the Amiga 500+ PCB with a few minor improvements. This circuit board can be bought off a gentleman Rob “Peepo” Taylor in the UK. It is a beautiful shade of purple and really is a work of art by itself.

Ordering the parts

It takes almost (90) different line items totally approximately (400) parts to recreate a modern Amiga 500+. These parts are generally ordered from Mouser, and cost in the neighborhood of about $150 or more. You still need to recover CPU, custom chips, RAM chips, and other parts from an original A500+. Or Ebay. Or Amibay. This project is a ton of work and while it’s mostly through hole, your patience will be tested with hundreds of hand-laid parts like capacitors and resistors.

No pick and place or wave soldering for me!

A500++ Parts ordered from Mouser

It’s really amazing at how many different parts it takes to recreate a 1980’s computer. Just look at all those. Even the image fails to give the true picture. Just bags and bags.

I’ve put about two nights of soldering in. I’d estimate that I’m in about 4 or 5 hours so far. I’m going for a “good job” versus a “fast job.” There are plenty of mistakes to be made here, and I don’t need to be blowing up any of the expensive custom chips I’ve needed to order separately.

My day-two state:

A500++ Day Two

Credit where it’s due

Here are the credits visible on the right hand side of the board:

Reverse Engineered by Rob “Peepo” Taylor.

Endless gratitude to Kai, Zoinks, Chrissy, Dr. A

Inspired by John “Chucky” Hertell.

 

Links

There’s no official website for the A500++. If you know of one, then please let me know via a comment below!

More work has been done, see DAY FOUR.

The community BOM is located here. It is a little more updated and clean than the official one. See: https://docs.google.com/spreadsheets/d/13xq2P7Ha_PA6r3vfPw77Q9PaSZYWncYfNpqhrwdvhaY/edit#gid=0

Fairly active Discord is here.

Email contact for buying a board is here: a500plusplus _ a t _ outlook.com. It costs about 60 GBP to the continental US.

 

keith

Amateur Electronics Design Engineer and Hacker

5 comments

Leave a Reply to Michael Ranger Cancel reply

  • I kind of feel sorry for the ambiguous “gentleman in England” getting so little credit for his work on making the replacement motherboard, with no links nor even mention of his name. A true work of art, just like if we were to refer to the Mona Lisa as just a portrait made by some Italian dude.

    • There’s no official link or site to speak of — not that I know of. You email the link I provided at the bottom of the post, send your money, get your board. There’s no documentation that comes with the board. You get a Discord server address and that’s it. No names shared or physical addresses involved.

      From the board itself, there are credits printed, and I’ll update the post to include those names.

  • Keith, could you be so kind as to narrow down the location of C701? I have a rev 2.1c and I’m beginning to doubt my sanity, either that or its been removed and the BOM does not reflect this update

  • This is a glorious build – I’ve done two of them and have a third blank on my wall in a frame as it’s so nice to look at. Rob and the guys on the discord are incredibly helpful if you get stuck, or need obscure parts.