ZX Spectrum diagnostic card (4 x ROM)

Diagnostic card - ROM for ZX Spectrum computer, with EPROM 27C512 chip with capacity of 64 kB. Allows to run four different ROMs of the computer instead of the originally built-in one.

Including a free EPROM with the card, on which the following programs are installed:

1. Gosh Wonderful ROM - alternative, improved ZX BASIC ROM.
2. ZX Diagnostics - diagnostic software
3. Retroleum DiagROM - diagnostic software
4. Ian Logan ZX Spectrum Test ROM - diagnostic software

The ROM card is used for service diagnostics of ZX Spectrum computers: memory, ULA, keyboard, EAR/MIC, image and sound. It also allows you to run modern, alternative ZX BASIC ROMs, improved over the original version from 1982.

The card supports EPROM 27C512 (64 kB - 4 banks), 27C256 (32 kB - 2 banks) and 27C128 (16 kB - 1 bank).
Works with computers:

• ZX Spectrum 48/+/128
• ZX Spectrum +2
• Timex 2048
• Harlequin 48/128
• Sizif-512

User manual: 
https://mumio.dev/wp-content/uploads/2023/04/A1_ExtROM_EN.pdf

ROM descriptions and more: 
https://mumio.dev/?p=256