Jupiter Ace

Hrm, hrm:

OK, you're right! In some countries it is illegal to re-engineer, but this cute home computer is really outdated - if it ever had a big time it had been in the early eighties.

Accidentally I got access to one of this rare machines. So I took some time to dive into its secrets. The results are a listing and a schematic in this small corner of home computer history. If you have some fun with it, I'm pleased. Because I had a lot of support by the ZX-Team, I wrote an article for the magazine. This text you'll find archived, however, it is german. Feel free to translate it!

Strange enough, a nice Spaniard named Isidro found it interesting to build an Ace himself. And even more strange, it is working! Please look below for pictures and more... A big Thank-You goes to him for reporting the "Last Bug"!


jupiter.zip Archive with listing, german text, and OrCAD schematics, 173KB.


Thumbnail of my schematic. Thumbnail of Isidro's schematic.
This is my schematic, with Isidro's corrections. (68KB) And this is the schematic of Isidro's selfmade Ace, he's using newer memory chips and a voltage regulator. (56KB)
If you click the pictures, you'll get the packed PDF files. It can be zoomed to get the labels and texts readable.

A hardware change for a 60-Hz-version can be found at http://www.jupiter-ace.co.uk/hardware_60hz_ace.html.

If you like to go further:

The operating system

The listing was made by disassembling and staring firmly on the code. Every now and then I ran the assembler to be sure not to make any errors, and so you can rely on it. Unfortunately I don't know of any source of a manual in the web. Just put your hands on a good book of Forth and start experimenting.

Selfmade Ace

Isidro Nuñez Blanco De Arenas took my schematic, corrected it a bit and built an Ace himself. His Ace is running well, this is his photo story:

A lot of work has to be done. But apparently Isidro is well prepared!
Photo of this.

Some hours later the main board begins to look like a home computer ;-)
Photo of this.

Now the Hour of Truth has come! What will Isidro see when he powers the thing?
Photo of this.

Photo of this.

And now Isidro's Jupiter is looking like an Ace!
Photo of this.

Horizontal Bar.

Who to blame:

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Comments and such stuff go to: [email protected]