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Computermuseum der Fakultät Informatik


intel 8008 single board computer

details
Detail view

This section of the environment of the processor shows, how much 
effort is necessary to connect statical memory to a 8008. Because 
in 1971, when Intel introduced the 8008 with only 18-pole IC cases, the
processors bus had to be triply multiplexed: For each memory access, 
the adress has to be read out in two parts via the only 8Bit bus and be
buddered externally(here with two 74LS273). Then, the memory is 
responding with a bit, which is carried by the same bus.
The interpretation of the processor states is done by the 74LS138
and the 74LS139. 
Thus despite of the multiplexers there are still not enough control 
wires for the  CPU, the highest part of the adress is carried out with
only 6 Bit. The so released two wires are used for both the control
signals cc1 and cc2.
On the other side, this restricts the adress space to16K.


Technical details are here.

details

A glance on the 1702-EPROMs. Each contains 256 Bytes.

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