ZX81 SP ROM Disassembly

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dbolli
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ZX81 SP ROM Disassembly

Post by dbolli »

Hi All,

I have created a disassembly of the Comprocsys SP ROM for ZX 81 from
an old printout I made in 1985.

The SP ROM by Comprocsys Ltd was an add-on card for the ZX81 that provided 256 x 192 bitmapped graphics, reading and writing of EPROMs and communication with peripherals through a Zilog 8255 PIA chip. It could be used in conjunction with the Comprocsys ASZMIC ROM or without (via ZX81 BASIC commands).

SP ROM Disassembly Xcode project is available here https://derekbolli.wordpress.com/2015/0 ... sassembly/

and an example BASIC program running in ZEsarUX Emulator is available here https://derekbolli.wordpress.com/2015/0 ... r-in-os-x/

Regards,
Derek Bolli
North Sydney, Australia
1985: ZX Spectrum+ 48K Interface 1 ZX81 16KB ASZMIC/SP ROM Philips 12" B/W TV Epson Dot Matrix Printer ZX Printer
Now: Late 2012 iMac 27" 3.4GHz i7 16GB RAM OS X 10.10.4 1TB Fusion Drive USB 3 HDs Ext iPad Air 32GB iPhone 6 64GB Apple TV v2
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siggi
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Re: ZX81 SP ROM Disassembly

Post by siggi »

Hi Derek
I have never heard of this interesting card. Thanks for sharing the information.
Will try to run VIRUS on my laptop-zeddy having ram @ 8K.

Siggi
My ZX81 web-server: online since 2007, running since dec. 2020 using ZeddyNet hardware
http://zx81.ddns.net/ZxTeaM
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Paul
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Re: ZX81 SP ROM Disassembly

Post by Paul »

Thanks for sharing this!
I own such a card with the sp rom missing.
I'm going to burn it and test.
Without your copy of the manual I would have been totally lost with this!
kind regards Paul
In theory, there is no difference between theory and practice. But, in practice, there is.
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