- Add support to query remaining usecs on pending events.
- Generalized the sim_interval adjustment in sim_idle to allow more than
a single decrement.
- More overhead reduction when idling.
- Carry usec values as double through out to fully support long wall clock
delays.
commit ef6528bf32 added support for automatic WRU detection for simulators
that don't have a console port, but it was never documented and the addition of
that support potentially interfered with SAVE/RESTORE behavior.
The console connection state is now automatically saved and restored.
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.
Also extended the optional VM supplied routines to include sim_vm_sprint_addr.
Simulators which provide sim_vm_fprint_addr should also provide
sim_vm_sprint_addr with sim_vm_fprint_addr reworked to leverage
sim_vm_sprint_addr internally. sim_vm_sprint_addr is currently only used by
sim_brk_message() which is an API which a simulator may choose to use if
it supports multiple breakpoint types,
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.
This allows simulator code to be insulated from any changes which may
be made to the REG structure in the future. The REGDATA macro will be
update as needed to avoid any changes in simulator specific code.
Update description of DEVICE, UNIT, and REG. Correct a number of
typos and formatting glitches. Add description of UNIT_IDLE,
REG_UNIT. Add some missing details in fprint_sym and
sim_vm_is_subroutine_call. Document command matching rule.
Altered the calling sequences to fprint_sym and parse_sym in ex_reg and dep_reg to merge user-defined register flags with the radix in the addr parameter. This allows the print and parse routines to identify the register or determine how it is to be handled. These are called in lieu of the standard print and parse routines if a register has REG_VMIO or at least one user-defined flag set.
simh.doc Writing a Simulator for the SIMH System
sim_breakpoints.doc The SIMH Breakpoint Subsystem
sim_vmio.doc Adding An I/O Device To A SIMH Virtual Machine
