jeff@felix.UUCP (04/11/87)
I'm contemplating a home project to add 512K more memory and a SCSI
port to my Mac512K. The additional circuitry will reside on a daughter
board which I shall connect directly to the original 68000. I do not
wish to alter the motherboard in any manner.
Can anyone provide answers to the following questions:
1) At what hardware base address is the NCR5380 SCSI chip located in
the Mac+?
2) What changes to the System must I perform to allow the new 512K
memory to be recognized as the lower 512K and the original motherboard
512K to move up 1/2M? (I'm under the impression that the
display/disk/souund buffers which reside in the motherboard RAMs should
always reside at the top of the allocated RAM space; is this correct?)
3) Should any such changes be placed in an application which
automatically is run after booting has completed or is an INIT the proper
method of performing such?
4) Would the 128K ROMs be required in order to allow booting from an
external SCSI drive?
Thankyou very much for any help.
--
Jeff Wallace
{decvax,ucbvax}!trwrb!felix!jeff
FileNet Corp. Costa Mesa, CA