Zx Spectrum Test Program Link Link

that tests memory banks, paging, and keyboard functionality. Retroleum DiagROM (Phil Ruston):

It provides a very clear visual map of the 4116 and 4532 RAM chips, showing you exactly which physical chip on the board needs to be desoldered. zx spectrum test program link

You're referring to the ZX Spectrum, a classic British home computer from the 1980s! that tests memory banks, paging, and keyboard functionality

Technicians would often create a "Test Link" by bridging specific connections on the edge connector at the rear of the machine. For example, to test the upper memory, a technician might force the machine into a continuous write/read loop to a specific address range. By connecting an oscilloscope to the data lines (the link between the program and the hardware), they could visualize exactly where the signal was degrading. Technicians would often create a "Test Link" by