binder@dosadi.DEC (10/31/84)
This is a summary of replies to my request for help with getting ProDOS to
boot on a "compatible" non-Apple machine.
1. I was advised to buy the book _Beneath_Apple_ProDOS_ which has a lot of
useful info in it, including a patch that tells how to make ProDOS use
40-track floppy drives. Unfortunately, there was nothing there that I
could use to fix my boot problem, but the book will get lots of use for
other purposes.
2. I received a patch to ProDOS, stated to be untried by the person who sent
it, which I tried. It didn't work; on a REAL Apple, the boot code put up
this message: "UNABLE TO LOAD PRODOS"
3. I was advised that all ProDOS looks for in the monitor ROM is the APPLE
trademark text that gets put at the top of the screen at boot. This fix
was claimed to have been tested.
Taking my cue from the third offering, I made a modified copy of my legitimate
Apple monitor ROM, with the lower-to-upper case foldover bypassed. To make
this change, load the ROM contents into a PROM blaster and observe the data in
address 583 (hex) - it is DF. Change it to FF and blast the appropriate new
PROM accordingly.
This modified monitor is in my machine now, and ProDOS likes it just fine. By
adding a small series of POKEs to my HELLO programme, I even have DOS 3.3
displaying and accepting lowercase commands.
Thanks to all who offered assistance!
Cheers,
Dick Binder ("Beware the Jabberwock, my son!")
UUCP: { decvax, allegra, ucbvax... }!decwrl!dec-rhea!dec-dosadi!binder
ARPA: binder%dosadi.DEC@decwrl.ARPA
Posted Wednesday 31st October 1984, 08:51 EST by DOSADI::BINDER