[att.sys.pc6300] PC6300 - chips for 640K

rps@homxc.UUCP (04/06/87)

I need to populate a 1 year old PC6300 out to 640K, it currently
has 256K in it.  My question is: can I use 256K chips or must
I use 128 or 64K chips?  I believe it currently uses 64K chips
to get up to 256K.  If I use 256K chips, do I have to change some
switch settings on the motherboard?

Thanks,

Russ Sharples
homxc!rps

gpw@ihdev.UUCP (04/07/87)

640K ON MOTHERBOARD OF PC6300---------
Leave the first two banks of 64K DRAMs in place ... then put 
256K DRAMs in the last two banks. Zap, you've got a 640K PC.

on DIPSW-0 (the one closer to the center of the motherboard)

sw1	sw2	sw3	sw4	location
off	on	on	on	128k on motherboard
on	off	on	on	256k on motherboard
off	off	on	on	256K on motherboard, 128K on expansion board
on	on	off	on	256K on motherboard, 256K on expansion board
off	on	off	on	256K on motherboard, 384K on expansion board
on	on	on	off	512K on motherboard-in bank 0
off	on	on	off	512K on bank 0, 128K on bank 1 of motherboard
off	on	off	off	128k on bank 0, 512K on bank 1 of motherboard

for 1.43 add sw 8 to 'off' if 256k chips are used

other switch combinations are meaningless.
Look carefully at the DIPSW to determine which is "off" and which is "on".

If you unsolder memory chips to install 256K chips you do so at your own
risk.
------------------------------------------------------------------------
256K chip sources:

	Microprocessors Unlimited		PH# (918) 267-4961
	24,000 S. Peoria Ave.
	Beggs, OK. 74421

	Parts are new 		shipping is extra:
						$6.00 Fedx standard
						$15.00 FEDx next day
	Usual procedure is to call give a VISA or MC # and pay by check
	upon recipt of goods. They supply the envelope. Instructions
	on handling are provided, and must be followed for the warranty
	to be in force.
------------------------------------------------------------------------
-- 
George Wilkin 	AT&T Network Systems, Naperville, IL 
		!ihnp4!ihdev!gpw  IH 4A-157  work 312-979-4317