Autorun System Information Cartridge for Sinclair ZX81 / Timex 1000

I’m offering a ROM-cartridge with System Info Software for ZX81 – working already with ZX81 in basic configuration with 1kB RAM.

It is a new ROM Cartridge showing important information about your ZX81 computer.

The firmware is started automatically after power on / reset. There is no need to start the software with RAND USR … or simillar commands.

As the firmware is started automatically, it can be executed even on computers having issues with the keyboard.

There is nothing loaded to RAM – the program is running directly from the (E)EPROM, therefore is running even with 1kB RAM w/o any issues.

Current firmware release is v2.11 or v2.12 .

Shall you leave the firmware, you can always start it again with the command RAND USR 8192, but as I wrote – after RESET the firmware starts automatically.

The software provides following information about the computer:

1. Size of installed RAM (typically 1kB, 2kB, 3kB, 4kB, 8kB or 16kB)

2. ROM type – following ROMs are recognized:

   1. ROM 550 – very first “buggy ROM”

   2. ROM 622

   3. ROM 649

   4. Improved ROM

3. Selected version: UK / US

4. Values of most important system variables

5. Memory map

6. Memory dump (whole memory space / ROM / RAM)

For every information a detailed screen with description is available – as can be seen on the pictures.

The cartridge itself is a board with 8kB (E)EPROM memory addressed in the address space from 2000h to 3FFFh.

In addition, a RESET button is placed on the board and a power LED indicating the presence of +5,0V power supply.

This listing contains the ROM Cartridge board only – there is NO ZX81 included. On the pictures it is shown just to demonstrate the functionality.

The board has been tested with several standard ZX81 computers and is working w/o issues.

Private sale: No warranty, no return.

Thanks for looking