Instruction manual

make it as simple as possible. I did not have any need to use disk space efficiently – I was using a 1 Gb
solid-state drive when I developed the system.
The disk drive plug needs to be oriented correctly. If keyed, as described above, it cannot go into the
connector backwards. However, if it is not keyed, you need to take care that pin 1 of the plug goes onto
pin 1 of the connector, which is marked by a 1 with a line on the circuit board, and by a small arrow
engraved on the plastic shroud of the connector. Note that in pictures of the IDE interface pinout, the
pins are numbered as shown on the connector plug, with 1 in the upper left corner.
If using a mechanical disk drive, you can use a computer power supply to provide power to both the
drive and the Z80 computer. Take the +5V and ground from the main power connector to the input jack
on the Z80 computer board, or to the connector for the logic probe, and connect the disk drive with a
drive connector. That way, both the computer and disk drive share the same ground, which is important
to prevent damage to the computer or the drive electronics.
Note in the above picture an AT-type computer power supply, with the hard disk drive receiving power
from one of the plugs coming from the power supply. The +5V power and GND for the computer are
coming from the proper pins of the main power supply plug. There is also a jumper wire between the
power supply ON input (PS_ON#, pin 14) and ground which is needed for the power supply to turn on.
If you are using a solid-state IDE drive, or a compact flash drive in an adapter with a separate power
connector, you can use the logic probe connector to supply low-current +5V power to the drive. You
will have to use your own wires to make the connection. Here are photos of a solid-state IDE drive and
a CF drive in an adapter, with attached power supply wires:
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