Hi all,
My system 80 (Black label, early model) Is getting some upgrades. First off I have fitted a socket for the fourth ROM position - Z13. To test this I hacked some code together which puts a few characters on screen, blew a 4K (2732) EPROM and popped it in. The machine is fine with no EPROM in the socket but crashes on power up with the EPROM fitted. The EPROM verifies and otherwise checks out electrically.
I read in a technical document that the socket is compatible with standard 27 series EPROMS, and human nature being what it is I have not bothered to question this.
Is there piece of information missing? Some systems require their utility ROMS to have a special header, for instance.
Any help gratefully received.
C