Load the . If the screen displays squares or corrupt characters, it is highly likely that your 4116 (lower) or 4532 (upper) RAM chips are dead. C. Replacing RAM If the test indicates RAM failure, you will need to:
Insert the device into the Spectrum’s rear expansion bus while the computer is powered off.
: Community tools like Phil Ruston’s Retroleum Diagnostic ROM provide advanced RAM and component testing for both original and 128K models. How to Use the Test Program To run these diagnostics on original hardware or emulators: New ZX Spectrum Next PLUS ! & A tape that doesn't exist ?! zx spectrum test program link
Identify the faulty chip (software will sometimes tell you which bank). Desolder the chip and install a socket.
to verify the health of both the lower 16K and upper 32K RAM chips. Floatspy & Interrupt Tests : If you're into low-level reverse engineering, the ZX Spectrum Reverse Engineering Blog Load the
The Spectrum’s ULA (an early gate array) is responsible for generating the video signal and handling RAM contention with the CPU. The test program checks the ULA by writing patterns to the screen memory area ( 0x4000 to 0x57FF in a 48K model).
This is arguably the most popular and comprehensive tool. It is designed to diagnose mass failure (dead ROM, bad RAM, stuck keys) and can be used on a SMART Card or written to a standard EPROM. Replacing RAM If the test indicates RAM failure,
If you are looking to test a Spectrum (16k, 48k, Plus, or 128k), these are the standard programs used by the community.
: A multi-purpose interface that includes the DiagROM firmware and an NMI button to trigger a keyboard tester at any time. Diagnostic ROM ICs
: This was a specialized ROM used by official engineers with the ZX Interface 2 . It provides a menu of tests to verify the system, including the Interface 1 and 2 themselves. You can find documentation and downloads at Spectrum Computing . 2. Modern Diagnostic ROMs
is a versatile utility that can operate as a 16kB ROM file. Its key feature is the ability to work on a ZX Spectrum without functioning ROM and RAM, using only a DIVIDE interface's ROM. It includes tests for 128kB memory, video RAM, fast RAM, and a tape signal tester .
Our website is available in different languages. We have detected "English" as your browser language or couldn't detect your language.