Atari XL expansion chassis

So I’m planning on building an expansion box for 8-bit computers with a parallel bus - the Atari XL was my first 8-bit computer that was useful (ie: had a disk drive) so that’s what I’m starting with. I hope to generalise it to the C64, and maybe more as well later on.

Anyway, there’s a website tracking the design and my progress - the first few entries might not be too interesting to this community, but the recent ones (while the PCB is away being made) have all been about how to build a PCI-like expansion box that plugs into the back of a mini-ITX case, in the ATX cpu opening.

If you’re interested, the progress blog is at and details both the successes and the failures of the project as time goes by. I’m a fan of “warts and all” progress, we all learn by making mistakes, and reading about why something didn’t work is sometimes as illuminating as reading about something that did.



Nice blog with pictures and explanations. Great for newbies to see what it takes to design and make things Look forward to seeing the progress!

What I find funny is that your CNC probably has more processing power than the Atari XL.

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What ?? Why you!!! Well, ok, I guess, sure. But to be honest, the simplicity is why it’s so much fun.

When computers lost the boot-to-built-in-BASIC, something of value was lost.

Dude, my first computer used paper tape, you entered the (37-bit, because why not) instructions using the 40-something toggle switches on the 6’ long front panel and bulbs indicated which bits were on or off for that instruction; output was to an honest-to-god teletype.

Please don’t make me re-live that. I’d almost managed to block those memories…

BASIC is good, BASIC is nice. BASIC is the safe zone. Enjoy BASIC.

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Relive your QuickBasic days here with an all new version!

Atari 400 with the membrane keyboard for me. We went through the entire Atari series and I loved them.

Damn how old are you guys. I’m in my 40’s and don’t remember any of that. Maybe I was to poor lol.

I’m almost 50. The Elliot 903 was the first computer I ever used (at school), and it seems that childhood memory isn’t the best permanent record (even if I am pulling this out of very cold storage…)

The machine was actually 18 bit and there were fewer switches - they did light up when activated though. The “programming language” was “SIR”, and the machine ran at 166 kHz. Yes, Kilohertz. It had 8K of RAM, which occupied a box about the size of a washing machine, and consisted of discrete ferrite cores, none of this VLSI nonsense, thank you very much!

About 2 years after they got the initial machine, the school spent a fortune on a Winchester Disk for the Elliot, it stored 512kBytes. It also, was the size of a washing machine. There seemed to be a standard-size for all Elliot modules…

The first computer I ever owned was the £49 Sinclair ZX81 kit, which I soldered together from components on a motherboard. To be honest, at that age I was more interested[*] in getting the black & white TV (which you tuned by turning the variable-capacitor dial, again, none of this “station preset” nonsense). I was 11 and I got it for Xmas. I got an Atari when Dixons were selling off stock (800 XL + Disk drive for £99).

[*] My parents had to nag me to actually build the computer. Eventually (about March I think) I got it working, and proudly set it up in the living room. The first test program the manual talked about was to type in:

PRINT 1 + 1 = 2

(where PRINT was just ‘P’ because the keyboard was tokenised). Anyway, after typing the above, the computer prints “1” of course, because 1+1 does equal 2, and ‘1’ is the logical value for ‘true’. My parents didn’t really get that. “He’s buggered it!”, my mum yelled through to my dad in the kitchen… It took a lot of persuasion (even though the expected result was in the manual) to get them to believe the thing was working…

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Haha NO! In the 6th grade we got to play with an Apple 2. That was top of he line. It made zero sense to me. You needed a bachelors degree to input anything. And a masters to understand what he results meant.

I had an MSX2+ with the Turbo flip switch. 4.77 -> 8 MHz

Those were the days!

I had one of these and an 800, too.