1 Jul
2012
1 Jul
'12
12:58 p.m.
On 1 Jul 2012 at 18:37, Oliver Lehmann wrote:
Done in discretes--the output of IC37e to TP4 at the Z80A is probably
very close to what's under the blue goo on that hybrid chip.
It should be fairly simple to verify. The input to the clock driver
should show about 220 ohms to the Vcc connection and about 710 ohms
to the ground connection. I suspect that HP didn't deviate too far
Probably very
similar to the Z80 clock driver shown here:
http://www.80bus.co.uk/pages/gemini/documentation/GM813_Circuit.pdf
Where exactly? Was not able to find it... from the recommended Zilog circuit.
--Chuck