compressed news on a 7300 with 512K RAM

[Thad P Floryan]

Regarding upgrading the memory of a 512KByte motherboard 7300 ...

So far I've upgraded one of my three 7300s.  I chose to upgrade the motherboard
myself since I have the tools and experience to do it properly.  Even then, it
took ~12 hours and IS tedious.

The parts required to upgrade my 7300 were:

1  74F258
72 Augat machined 16-pin sockets
72 256Kx1 150nS DRAM chips (used both Hitachi HM50256P-15 and NEC D41256C-15
   since I just happened to have a few tubes of each in my "standard stock.")
1  jumper wire, made by clipping a lead from a resistor.

My system(s) already have a resistor pack at RP4, so I didn't have to do
insert a new one.

A motherboard upgrade presents you with zero wait-state memory.  Expansion RAM
cards have (apparently) 1 wait-state.

The choice of a motherboard swap, direct motherboard upgrade, or adding a RAM
expansion card will have to depend on your [de-]soldering skills and the costs
of the three choices; I cannot make that decision for you.

But I *CAN* say that a RAM upgrade is definitely worth every penny you put into
it in terms of improved system performance.  I put 2 systems side by side, one
with 2MB motherboard and the other with 512K motherboard, and started the same
things on both (otherwise) identically-configured systems ... the 2MB system
wins every time, in many cases VERY noticeably.  Personally I would recommend
(somehow) bringing your motherboard up to 2MB, then adding 1.5MB or 2MB RAM
expansion (depends whether you use the EIA/RAM combo card (1.5MB max) or just
a 2 MB RAM expansion card (which can be "made" by upgrading a 512K RAM card).

Thad Floryan [ thad at cup.portal.com (OR) ..!sun!portal!cup.portal.com!thad ]