15
The current select codes of all devices are displayed with the
SHOW DEVICES
command. The default settings
are:
Device
Name
Select
Code
Initially
Disabled
Device
Name
Select
Code
Initially
Disabled
PTR
10
MSD
30
TTY
11
MSC
31
PTP
12
IPLI
32
TBG
13
IPLO
33
LPS
14
DS
34
LPT
15
BACI
35
MTD
20
MPX
36
MTC
21
PIF
37
DPD
22
MUX
40
DPC
23
MUXL
41
DQD
24
MUXC
42
DQC
25
DA
43
DRD
26
DRC
27
For devices with two interface cards (e.g., DP), specify the lower select code with either device name; the higher
select code will be set automatically, and the cards will be assigned in the correct order. If a select code conflict
occurs, the simulator will report the error when program execution is attempted. In simulation, empty slots behave
as though they contain HP 12777A Priority Jumper Cards, so the device assignments need not be contiguous.
Because they are used infrequently, the LPS, MTD and MTC, and IPLI and IPLO devices are initially disabled.
The select codes of the CPU, MP, and DMA/DCPC devices are fixed and cannot be changed or displayed.
2.2.11 SAVE and RESTORE
SAVE
and
RESTORE
are supported only when the simulator executable used to restore the simulator state file is
the same simulator executable used to save the file. Correctly restoring the state of the simulator depends on the
layout of internal structure variables being identical to the layout of the structure variables that were saved. This is
guaranteed only when using the same executable, as the layout used is implementation-defined.
2.3 Realistic, Calibrated, and Optimized Timing
Devices simulate their I/O operation delays (disc seeks, magnetic tape reads, printer paper movements, etc.) by
counting specified numbers of “event ticks.” For example, a disc seek completion might be scheduled to occur 500
event ticks after command initiation. Generally, one event tick is counted for each machine instruction executed,
although some complex instructions may count an event tick for each internal step of the instruction (e.g., for each
word moved within a block-move instruction). Device simulations provide commands that determine how the
appropriate tick counts are selected for I/O operations timing:
Command
Action
SET <device> REALTIME
Configure the device to use realistic timing
SET <device> CALTIME
Configure the device to use calibrated timing
SET <device> FASTTIME
Configure the device to use optimized timing