Cromemco TU-ART Board
This was the main I/O board Cromemco
utilized for their systems to communicate with the printer or CRT terminal(s).
The TU-ART (Twin Universal Asynchronous
Receiver and Transmitter) provided two channels of duplex serial data exchange;
two channels of parallel data exchange; and ten interval timers. Status
information was available through polling or via interrupt. In
addition, each interval timer activated an interrupt and two interrupt request
lines were brought out for the user. The TU-ART has its own crystal-controlled
clock and interfaces to the S-100 bus asynchronously so that CPU clock frequency
was not critical. The board incorporated two TMS 5501 NMOS I/O Controller chips. The
only problem with the board was that it ate up a big chunk of the 256 byte
system I/O address space. Below is table of the essential requirements.
Also the board was quite tricky to program/interface particularly for
interrupts. If you are using this board take care also you connect the
right pins on the top edge connector to what you require. The
TDL SMB for example required only 2
ports per I/O function.
The manual for this board can be
Other Cromemco S-100
4FDC 16FDC 64FDC
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