6300 Memory upgrade

[Peter Fales]

> In article <7191 at topaz.RUTGERS.EDU> gopstein at topaz.RUTGERS.EDU (Richard Gopstein) writes:
> >
> >  A friend has an ATT 6300 with one floppy drive and one 10M
> >hard disk purchased about a year ago.  The system came with 256K
> >RAM on the motherboard, and he is interested in upgrading the
> >system to 640K.  Unfortunately, he thinks that all of the existing
> >chips (64K)? are soldered directly to the motherboard.  Did they
> >really do this?  If so, what are his options?
> 
> This is not true. There are 2 banks - one is soldered-in 64K chips, the other
> is socketed with (in his case) 64K chips. What he needs to do is buy 18 256K

Sorry, he may not be so lucky - Some early 6300's were shipped with one bank
soldered and one bank socketed, later models have both banks soldered.  I
understand that dealers are hanging on to the socketed models to sell to
customers who want 640K systems, making it even more difficult to get a
hold of a socketed system.

There are several alternatives:

1) Unsolder the bank 1 chips and replace with 256K parts.  Someone on the
   net was advertising this service for (I think) around $100 plus parts.
2) AT&T sells a 384K memory expansion board that plugs into a 16 bit expansion
   slot.  I understand that this is slightly slower than motherboard memory
   because it uses one extra wait state.
3) It is also possible to use third party memory expansion cards.  This
   can have a considerable impact on sysem performance due to the eight
   bit rather than 16 bit transfers.

Peter Fales
ihnp4!ihlpl!psfales