As I understand it, all issue 4 and later production boards were only ever supplied with the combined OS and BASIC mask ROM.
Mask ROM chips are normally very reliable. EPROMs may suffer from data loss, but mask ROM chips are very different.
Yes, occasionally they may go wrong, or be damaged.
If the ROM is in a socket, you could read it in a programmer (or other suitable device), select a 27C256 as that's the equivalent sized EPROM. Or, if it's soldered in, if you remove the processor and ULA, you may be able to rig up a circuit to read it while it's still in the Elk.
ROMs are static, therefore there is no minimum clock to worry about.
Mark
Mask ROM chips are normally very reliable. EPROMs may suffer from data loss, but mask ROM chips are very different.
Yes, occasionally they may go wrong, or be damaged.
If the ROM is in a socket, you could read it in a programmer (or other suitable device), select a 27C256 as that's the equivalent sized EPROM. Or, if it's soldered in, if you remove the processor and ULA, you may be able to rig up a circuit to read it while it's still in the Elk.
ROMs are static, therefore there is no minimum clock to worry about.
Mark
Statistics: Posted by 1024MAK — Thu Jun 27, 2024 10:30 pm