Hi,
I've just made a small RAM diagnostic ROM for the CPC. It fully run from ROM and will let you know if the main bank RAM are OK or not.
To use it :
- On all CPC, you will need a LowerRom board or an XMEM and program the provided .bin file. Use the xmem in boot mode.
- On a plus, you can put the .bin or .cpr in a C4CPC free slot and start from it, or program the .bin on an EPROM in a salvaged cartridge.
The program first test the display area (C000-FFFF), should see something like :
The content of the screen will change during the test. So if nothing move, more than the ram may be wrong.
Something else is wrong if you do not see that screen at all.
Then it will display the results :
If all is good, the band will be all green :
In case of error, the bad data bit will displayed red
In this example, the 4 LSB bit are wrong.