MITS - 8080 CPU
This board has the distinction as being
the first S-100 board ever designed. The layout of the board with its
pinout from the 8080 CPU essentially defined the function of the S-100 bus pins.
This board looks primitive by today's
standards but it should be remembered that then some minicomputers did not have gold plated edge connectors. The CPU was clocked
at 2MHz. It utilized Intel's 8212 chip to define a number of the "Altair" bus
lines. The only other significant component on the board was a Molex connector
to allow a connection to the computers front panel switches. These allowed the
CPU to be single stepped, programmed etc. Note the relatively scarcity of
plated through holes on the board. The shortest route traces to the 100 pin edge
connector defined the bus signals. Unfortunately this layout was not
optimum from a signal noise perspective. However the good news was that there
were many unused connectors pins that later allowed the bus to be extended to
complex 16 bit CPU systems and the IEEE-696 format.
There was no separate manual for this
board. The relevant pages from the Altair Computer Kit manual can be obtained
here. They are included here to show
the detail that was supplied in constructing the Altair Kit.
The schematic
for the board can be obtained
here.
Other MITS S-100 Boards
1K RAM
4K RAM
4K Dynamic RAM
16K RAM
16K Dynamic RAM
4PIO
8080 CPU VI/RTC
PCI ADC
2K PROM
8K PROM
88-2 SIO
SIO-B
MITS FDC Boards
This page was last modified
on
01/08/2011