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4 Programmed General I/O Device Simulations
The simulator provides these general I/O device interfaces and their associated peripherals:
•
12531C Buffered Teleprinter Interface
•
12539C Time Base Generator
•
12597A-002 Tape Reader Interface
•
12597A-005 Tape Punch Interface
•
12620A/12936A Privileged Interrupt Fence
•
12653A Line Printer Interface
•
12792C 8-Channel Asynchronous Multiplexer
•
12845B Line Printer Interface
•
12875A Processor Interconnect
•
12920A Asynchronous Multiplexer Interface
•
12966A Buffered Asynchronous Communications Interface
4.1 12531C Buffered Teleprinter Interface with One 2752/54 Teleprinter
The 12531C Buffered Teleprinter Interface connects current-loop devices, such as the HP 2752A (ASR33) and
2754A (ASR35) teleprinters, as well as EIA RS-232 devices, such as the HP 2749A (ASR33) teleprinter and HP
2600 CRT terminal, to the HP computer family.
This simulation provides three units. Unit 0 reads from the teleprinter keyboard. Unit 1 writes to the teleprinter
printer. Unit 2 writes to the teleprinter paper tape punch. Attaching a paper tape image file to unit 2 simulates
loading blank paper tape into the punch:
ATTACH {-N} TTY2 <image-filename>
Adding the
–N
(new file) switch clears the contents of the image file if present. Without the
–N
switch, punch output
will be appended to any preexisting image file content. Detaching the image simulates removing the punched tape.
The interface may be programmed to enable printing and punching separately. Only the HP 2754A teleprinter
responds to the individual enables. All other supported devices print if either the printer or the punch is enabled.
The TTY device simulates an HP 2754A only if the punch unit is attached. When the unit is detached, an HP
2752A is simulated, which will print if either printing or punching is enabled.
If the host operating system returns an error when writing to the paper tape image file, the simulator will report the
error to the simulation console, e.g.:
HP 2100 simulator teleprinter punch I/O error: Permission denied
...and the simulator stops. Simulation may be resumed and the operation retried if the problem has been corrected
or with the punch operation incomplete if the problem is uncorrectable.
