Sinclair ZX80 / ZX81 Forums

Thank you for your thorough answer.

Since ZX80 and ZX81 are much alike. The ZX81 has added NMI/Sync.

So can I get my ZX81 to act exactly as a ZX80 by just changing the ROM?

My “The ZX81 Pocket Book” is written by Trevor Toms.

With this software from Wilf Rigter, can set the screen to any size, and giving more time to run code. When less time is used for display, then more can be used for code.

http://www.user.dccnet.com/wrigter/inde ... va2005.htm

Bought one from him 25.09 this year. So I think he puts new supplies on SellMyRetro from time to time.

Last I heard he was busy putting food on the table.

Please tell us if it’s working.

:oops: "26" n/l "00" n/l "2E" n/l "2A" n/l "C9" n/l "S" n/l RAND USR 30000 Not: "2600" n/l "2E2A" n/l "C9" n/l "S" n/l RAND USR 30000 I would assume they would give the same results. If you use LD B,01 LD C,02 RET You can get the output to Basic with PRINT USR 30000 PRINT USR 30000 would in this ca...

You cannot have RAM enabled in the same area on the Minstrel and the Chroma. Chroma has DIP switches for this. Maybe the Minstrel has some jumpers for this setting on its device. However Chroma might need to have RAM enabled where screen and color is stored, for video output to work through the Chro...

And again Mark’s invaluable help, knowledge and kindness to help.