[sci.electronics] Microsoft memory upgrade -- HELP!!

ugweiksn@cs.buffalo.EDU (John Weiksnar) (12/18/87)

	First of all, please: no jokes about the PCjr!

	I have a stock Microsoft sidecar with 128K of
	4164 memory (and RTC & mouse) which I must
	upgrade to 512K with 41256's. I am told that
	simply popping the 256K DRAMS into the old
	sockets and resetting the switches will not
	do the trick...must be an addressing problem.

	Do you have any experience with this matter?

	I know that a firm in Arlington Texas charges
	$150 for this operation, but I'm sure it's
	only a matter of cutting a trace, adding a 
	jumper, or something simple like that--at
	worst, adding some LS chip. Also, Microsoft
	no longer carries ANY information on the unit,
	and never published a schematic.

	Please reply to v056pxb4@ubvmsc.BITNET.