[net.micro.mac] Cheap 512k->1 Meg upgrade

palmer@cit-vax.Caltech.Edu (David Palmer) (05/21/86)

Organization : California Institute of Technology
Keywords: upgrade

	Has anyone had any success with the low price 512k->1 Meg upgrade
posted on the net a few weeks back.  (That upgrade, posted by Mike Ching
as a binhexed macpaint doc. involved the piggyback soldering of an
additional 512K on top of the existing memory.)

	My friend and I tried it on a mac (64K ROMS, Dr. Dobbs style
homebrew 128k->512k upgrade).  The original 512k works fine, but when I try
to address memory in the upper 512K, the data is written in pseudo-random
places in the lower 512K.  (Each different address in memory goes consistently
to a different (but wrong) location in RAM)

	Has anyone else done the upgrade and had this problem, or done
the upgrade and had different problems or even success?

	Thank you in advance.

		David Palmer
		palmer@cit-vax.edu