OS version 2.49 requires EPS firmware (Eprom chip version) of 2.40. If you need
an earlier OS version, let me know. To find your firmware version, press
Command, then Env 1 (Display then says:) "NO COMMANDS ON PAGE", but ignore this.
Scroll right until you get to "SOFTWARE INFORMATION", and then press Enter.
Displays current "RAM VERSION" (O.S. version you are using). Press Enter again
to display "ROM VERSION" (this is your firmware version). If you don't
have an OS disk, the only way to determine your firmware/ROM version is to open
up the top lid (4 hex screws) and inspect the two EPROM chips labeled "UPPER"
and "LOWER" on the main board. The version will usually be printed on the chip labels.
If they are 3rd party EPROMs, then guessing is all that's left. At least 90% of
EPS's that I have seen can use OS V2.49. (ROM V2.40) I recommend trying V2.49
first if you are not sure of the ROM version. The wrong version will not harm
the machine, it will just shoot an error such as: "INCOMPATIBLE OVERLAY".
If you are getting the error "DISK NOT FORMATTED", or DISK DATA CORRUPTED",
you may have a faulty or dirty disk drive.