Tristan Mumford wrote:
Michael J. Mahon wrote:Tristan Mumford wrote:- on the location of RAM in an apple][ -That sounds like a nice test to me. It will be the first thing I try.Aaack! I got it wrong *again*! As Jorge points out, Row C (on the PC board edge) is the low 16KB, row D is the middle, and Row E is the high ($8000..$BFFF) row. It has *definitely* been too long since I played with my ][+. ;-)Tsk tsk. I'll bet its in a corner sulking.
It's currently sleeping--out with a bad ROM (shorted!), but has become resigned to playing second fiddle to my //e. ;-)
Maybe the drive select line could be used to do the side select?One of my many ideas too. It would be rather nice to have two "disks" in the one unit. I discovered I was limited by a crippling lack of 20 pin ribbon cable though. The one I'm using I pulled from a very convincing clone Disk ][. The only indications that it isn't the real deal is lack of labels and no apple branding on the circuit board. nice quality though. It's made of what seems to be 1mm plate steel.
I've been known to split old 40-wire IDE cables in half... -michael NadaNet networking for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."