Parallel Interface Signals And Levels - Radio Shack TRS-80 Model III Operation Manual

SPECIFICATIONS
Parallel Interface Signals and Levels
The Model II includes a parallel interface designed for connection to a line
printer via the 34-pin connector on the back panel of the Display Console.
Eight data bits are output in parallel, and four data bits are input. All levels
are TTL compatible.
The connector pin-outs and signals available are listed on the next page.
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