PSIONICS FILE - ENVVARS
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Environment variables
Last modified 1994-03-28
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The following environment variables are known:

"P$D": printer device: 1 byte:
  Offset  0 (byte):
    48 = print device is a parallel port
    49 = print device is a serial port
    50 = print device is a file

"P$S": serial port setup: 12 bytes:
  @Unknown, but includes fields called tbaud, rbaud, frame, parity, hand, xoff,
  xon, flags, tmask@

"P$F": print to file name: up to 128 bytes:
  Offset  0 (cstr): last file used for printing to file

"P$M": printer driver: up to 129 bytes:
  Offset  0 (byte): printer driver model number
  Offset  1 (cstr): printer driver library
A printer driver library can support several similar printers; the model number
specifies which is selected.