magnusfalkirk wrote:
On Aug 25, 1:15 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:It doesn't help that my IIc and IIc+ schematics are all but unreadable.. -michael AppleCrate II: An Apple II "blade server"! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."Michael, you should have that copy of the //c schematic that I copied from the //c Technical reference. If you can't find them I can always e- mail you a second set.
Yes, I checked that and another set that Bill Garber emailed, but I note that neither shows the PB circuitry. So I'll have to go with the "abstracted" PB schematic in the manual. The good news is that it now appears that WRPROT will do the job as long as the state machine is left in the "shift in WRPROT" mode. FWIW, while I was perusing schematics, I noticed that XDIR (pin 4 on the 9-pin game port) is apparently a straight logic level input, and would be much easier than a PB! -michael AppleCrate II: An Apple II "blade server"! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."