Sinclair ZX80 / ZX81 / Z88 Forums

The Brazilian ZX81 clone, TK85 came with an extra 2K ROM at 8192-10239 with hi speed (4200 bps) save, load and verify, and what they called DSAVE, DLOAD and DVERIFY, which would save the contents of a string to tape. Strings on the ZX81 are more like byte arrays, and can contain binary data. This st...

The Brazilian machine code monitor, MicroBug allowed you to save memory blocks in 300bps (standard), and 1200 bps, by altering the wait loops. The TK85 clone had a high speed save and load feature that operated at 4200 bps, based on QSave. One of the differences is that QSave saved 16K blocks, and t...

I'll probably end up being embarassed if I post any more details on the hardware hehehe. I designed it with 3 x 8255 for digital I/O and a pair of ADC0809 for analog inputs. I made up a plant control panel with anunciators, and had all the outputs running, at least enough to show the university pane...

Hi there! I'm a Brit living in Brazil since late '79. I still have my TK85, but the keyboard membrane died several years ago, and I had to solder in a rewired PC keyboard. A lot of ZX81 software was copied (without permission), translated and resold on the Brazilian market by local companies. Microd...

Reviving a 10-year-old thread... did you manage to scan this in, Paul? Is it available online anywhere?

Cheers

Simon