Reading a ROM

[Martin Hepperle]

Dave,

when the software was developed, EPROMs larger than 32 KB were probably not yet available.

A 64KB EPROM (27C512) is possible without problems.

You would configure a half bank with
EDISK.SYS /2 /H
to create a .HAF file with 63488 bytes on ram drive D: or e:

With two 64 KB EPROMS in a full-bank configuration you can thus store a directory with up to almost 128 KB data.
EDISK.SYS /2 /F
would make a set of EVN and ODD files on ram drive D: with a combined capacity of 129024 bytes.

128 KB per EPROM is only possible with some adapter - the Personal Software solution was to solder PLCC EPROMs onto a carrier PCB and use some jumpers and wires to switch between programming and operation modes.

Some EPROM software/burner combinations can read ROMs too, but not necessarily. One would possibly also need an adapter. and, please avoid feeding the high programming voltage to a ROM. The 12 V level may also be used to read the manufacturer ID from an EPROM, so one should switch this option OFF when trying to read a ROM as EPROM (or read as a generic EPROM).


Martin