Miniwave Expander Assembly Instructions
Power
Power is supplied to the PCB by a standard MOTM / Blacet AMP .156 MTA
connector at 15V. The on board regulator brings the voltage to +5V necessary to
run the circuitry.
Sockets
I would recommend the use of sockets for the 9 EPROM locations to allow
removal of the EPROMS. The board has been designed with the EPROMS fairly
close together, so some ZIF sockets may not fit. The Aries Lo-Pro ZIF, and the
Aries Lock/Eject DIP Socket (same as the Miniwave “B” socket) will fit with no
problems.
The socket for J1 which receives the DIP28 plug to connect to the main Miniwave
board
must
be of the screw machined variety such as the Mill-Max 110 series.
The DIP28 plug will not reliably stay connected to a leaf socket.
This also means that the “A” socket on the Miniwave needs to be dealt with as it
is a leaf socket and the DIP28 plug needs to plug into that socket. What seems
to be the best approach is to plug a Mill-Max 110 series socket into the Miniwave
“A” socket, and then plug the DIP28 plug into the Mill-Max socket.
Modification To The Miniwave
In order for the switching to work with 10 EPROMS, it is necessary to remove the
A / B bank switch on the Miniwave by de-soldering S1-1, S1-2, and S1-3. Then
run a jumper from S1-1 to S1-3. This will allow the remaining EPROM in the “B”
socket to be selected by the expander board switch as EPROM 0. Remove
resistors R26 and R27 from the Miniwave, they are no longer needed.
Switching Circuit
□
Solder in 100K resistors R0-R9.
□
Install a MTA .100 10 pin header at J3 for the rotary switch to connect to. The
switch could be wired directly to the board if desired. Connect the common lug
on the switch to the ground pad on the expander.
Do
not
install J4 header, or the 74C42 at U10. These components were
intended for BCD switching which proved to not operate correctly.
