🚀 go-pugleaf

#R:isrnix:9600001:uok:10700001:37777777600:1473
uok!bsouther    Oct 26 03:15:00 1983

I have never experienced the problems you have described (exactly), but
there are certain things that are inherantly bad about using ANY memory
expansion on the zx/81:
	1)  The interface connector on the zx/81 is electronically
		unsound when it comes to reliability.  You can't
		firmly attach your Memopak or other expansion without
		lots of tape, and even if you can secure it, the
		contacts are prone to oxidation and subsequent loss
		of electrical contact after a short time.
	2)  The memory decoding on a zx/81 is tricky, with the
		bulk of the decoding done by the computer's "do-
		everything-including-pick-your-nose" chip.  It
		appears that this chip was designed to work at
		100% efficiency iff there is no additional memory
		(beyond 2K).  If any expansion is done (of any
		sort, including just adding a printer), this
		chip tends to "drop" data somewhere off in a
		bit bucket at random intervals.
Perhaps your problems are ROM based, but more likely you are just
experiencing localized troubles whereas the rest of us haven't been
able to pinpoint one specific event which causes data losses.  I have
no help for you, but just thought it might make it easier on you to
know that I've yet to find anyone who has a zx with expansion that
has NOT experienced (relatively) high data dropouts.  If you CAN find
some way around this annoying occurance, *PLEASE* post it so the rest
of us can benefit, too!

		Brad Southers
		Univ. of Oklahoma
		uok!bsouther