🚀 go-pugleaf

	We finally got some ROMS and we had four machines that we had
upgraded to 1 Meg. Here is a set of experiences that may help some
people that may run in the same problems that we did.
	All the machines were running fine with the upgrade and
without the resistors. I put all 6  68 O (O == ohms) resistors in, and
it worked fine with the Roms and all.
	Now we went to do my office mate's machine. We put the 68 O
resistors, no roms and the machine recognized the upper 512K, but we
started getting random errors (looked like the rams we not holding
data). So we took one resistor out of the pin 4 (RAS) bus of the upper
512K and hooked the bus directly to the MM chip. Worked fine (the 68 O
resistors were in on the 2 pin 15 (CAS) busses of the upper 512K). The
lower 512 K was doing just fine with all the resistors in. The only
difference between between this machine and mine was that I had
Hitachi chips and this machine had Oki chips. So we guessed that they
had different operating points, and so we tried a lower value
resistor, 39 O on the pin 4 (RAS) bus. This time we started getting
consistent errors (every alternate address above 512K read FE instead
of FF). So we went for a even lower value resistor, 27 O, and then
everything worked out just fine. Now we have the Rom in, and its doing
just fine. Has anyone else come across such problems??
	We mounted our resistors on a little piece of PCB and stuck it
to the left of the Rams, and ran wires from the MM chip to the
appropriate spots (after cutting the 3 lines ( RAS and the two CAS's
of the lower 512K), instead of soldering the resistors to the traces
or the memory chip directly.
-- 
					Jwahar R. Bammi
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