System information

The actual devices attached to any particular computer system are driven by subroutines in the
BIOS portion of CP/M. Thus, the logical RDR: device, for example, could actually be a high
speed reader, teletype reader, or cassette tape. To allow some flexibility in device naming and
assignment, several physical devices are defined in Table 1-3.
Table 1-3. Physical Devices
Device Meaning
TTY: Teletype device (slow speed console)
CRT: Cathode ray tube device (high speed console)
BAT: Batch processing (console is current RDR:, output goes to current LST: device)
UC1: User-defined console
PTR: Paper tape reader (high speed reader)
UR1: User-defined reader #1
UR2: User-defined reader #2
PTP: Paper tape punch (high speed punch)
UP1: User-defined punch #1
UP2: User-defined punch #2
LPT: Line printer
UL1: User-defined list device #1
1.6 Transient Commands CP/M Operating System Manual
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