Clock ticks for these simulatrs are performed by programmatic setup of the
interval timer device (TMR) and have nothing to do with the TODR which
increments at 100Hz, but doesn't generate ticks to the simulated system.
When the TODR device (CLK) is attached to a state file, it operates in OS
agnostic mode. This file can now be ported between hosts with different
endianness and work consistently to track the time of year.
Additionally, the VAX and VAX750 TODR values now properly don't
progress when they have zero values (or when they overflow back to zero).
Asynchronous clocks are now built for all simulators which are built with
SIM_ASYNCH_IO defined. The default behavior has asynchronous clocks
disabled since this is still experimental, but it can be enabled with
SET TIMER ASYNC.
Catchup clock ticks are now available, but since they're experimental,
they aren't enabled by default. Catchup ticks are only available if the
simulators clock device calls sim_rtcn_tick_ack to acknowledge processing
of clock ticks. The VAX simulators have been modified to leverage this.
Catchup clock ticks can be enabled with SET TIMER CATCHUP
Additionally, an idle threshold is provided which can be used to
influence when clock calibration may be suppressed. The default is not
to suppress calibration activities.
The various timer behaviors are visible with the SHOW TIMER command.
The state of the operating timer facilities is visible with: SHOW CLOCK
Timer events which are queued are visible with the SHOW QUEUE command.
Polling is now done at least every 500ms even if the prior input
character hasn't been processed yet. This allows ^E to provide a way
to exit a simulator which otherwise isn't reading from the console port.
These changes facilitate more robust parameter type checking and helps
to identify unexpected coding errors.
Most simulators can now also be compiled with a C++ compiler without
warnings.
Additionally, these changes have also been configured to facilitate easier
backporting of simulator and device simulation modules to run under the
simh v3.9+ SCP framework.
The reboot command code was not defined, and even when defined, it didn't get executed before the simulated code executed a HALT instruction. Solved by scheduling immediate execution of reboot command.
Writing to the TXCS register always updated the transmit enable mask, even when the "Write Mask Now" bit was not set. That bit needs to be set for the write to the register to actually update the transmit enable mask.
The goals here being to simplify calling code while getting consistent output delivered everywhere it may be useful.
Modified most places which explicitly used sim_log or merely called printf to now avoid doing that and merely call sim_printf().
