Tony wrote :
But be warned that 'my' scheamtic there is an
early version, and I know I
made an error in the address decoder circuit (basically I miscounted the
address pins on the CPU at one point). The HPCC CD-ROM contains an updated
There is also a small error in the psu circuit one of the diodes in the -12V
circuit is a zener.
The last one before the 7912 regulator is a zener diode witch protecs the
regulator and the two rectifiers.
If you replace it with a normal diode you blow CR22 I found out ;-(
It should be replaced with it's original 1N5568