Cromemco D+7A I/O
The Cromemco D+7A I/O board was a very
specilized board produced early in the company history to allow the use of two
Joy Sticks to be used with their Dazzler board. However it was a very powerful
and useful general analog to digital converter board.
The board provided one digital and 7
analogue input/output ports to be utilized. The board was completely
port addressable with the lowest port being the digital parallel port.
Cromemco software uses ports 19H to 1FH. The analogue to digital
conversion was done using a MC 1408L D to A chip. The seven analogue ports
each had a range of -2.56 volts to +2.54 volts. The voltage is represented
as twos complement with the least significant bit representing a 20
There was an excellent discussion/write
up about this board in the July 1997 Interface Age magazine.
That article can be
Other Cromemco S-100 Boards
4FDC 16FDC 64FDC
This page was last modified