Add consistent debug options to track TODR activities and the values which
are set. Debug data will display the VMS time related to the values set and
read.
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.
Removing pseudo ticking of the TODR improves simulator behavior
when idling. As previously implement, the timing of the TODR and TMR
ticks weren't aligned and and idle simulator would have to wake up to
service both tick activities.
The real hardware has a TODR which changes every 10ms to reflect changes
to wall clock time. This is already completely achieved by referencing the
host system time whenever the TODR register is referenced. No need for
to simulate pseudo ticking.
The real interval timer hardware generates ticks a the rate specifically
programmed in the interval timer device registers. The common cases
programmed the ticks at 10 ms intervals (100Hz), but real operating systems
exist which programmed ticks at 16667 usecs (60Hz).
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.
- Previous changes made to support 32V's 60HZ clock tick introduced changes
which didn't properly handle increments and interrupt generation while single
stepping the timer.
- The icr_rd routine returned an incorrect value when interpolation was
necessary due to a missing cast when converting from double to uint32.
- Properly start the timer from the current state of the interval count register
when the timer was previously stopped.
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 original implementation coupled the elapsed time measurement
to the 100Hz internal calibration clock. This worked well enough for very
long intervals but not well at all for any intervals less than 50ms. The net
result is that it couldn't usefully be used to produce the 60Hz clock ticks
which Unix 32V used it for. It now leverages the microsecond timing
provided by sim_activate_after(). This problem is reported in #253
This is necessary to avoid kernel type ahead buffer overruns when a user
pastes a chunk of data into a console session as described in issue #246
Other console input speeds can be set with SET CONSOLE SPEED=nnn
Fixed auto configure bugs which didn't allow Fixed CSR Addresses or Fixed Vectors to be set using the auto configure information.
Fixed display of address and vectors to indicate that the assigned address and/or vector is in the floating set.
Added extended definitions to the auto configure table to reflect all known potential static and floating and static addresses as of VMS V5.5-2
Changed the name of the VAX 11/780 console floppy device name to RXC from RX (which collides with a Unibus name for the RX11).
Unbound the TODR value from the 100hz clock tick interrupt. TODR now behaves like the original battery backed-up clock and runs with the wall clock, not the simulated instruction clock (except when running ROM diagnostics).
Two operational modes are available:
- Default VMS mode, which is similar to the previous
behavior in that without initializing the TODR it
would default to the value VMS would set it to if
VMS knew the correct time. This would be correct
almost all the time unless a VMS disk hadn't been
booted from for more than a year. This mode
produces strange time results for non VMS OSes on
each system boot.
- OS Agnostic mode. This mode behaves precisely like
the VAX780 TODR and works correctly for all OSes.
This mode is enabled by attaching the TODR to a
battery backup state file for the TOY clock
(i.e. sim> attach TODR TOY_CLOCK). When operating
in OS Agnostic mode, the TODR will initially start
counting from 0 and be adjusted differently when an
OS specifically writes to the TODR. VMS will prompt
to set the time on the initial boot unless the SYSGEN
parameter TIMEPROMPTWAIT is set to 0.
I’ve always wanted to have the option to have simulated devices behave
more naturally with respect to I/O operations. By more naturally I
mean that the current simulator model I/O is either polled (for asynchronous
things link Muxes and Network), or it is performed in the middle of some
instruction execution taking possibly many milliseconds (disk and/or tapes).
The existing model creates quite deterministic behavior which helps to debug
and understand issues, but it trades off potential instruction execution
while performing these I/O operations in between instruction execution.
To address this concept (while still retaining the potential advantages of
the original model), I’ve designed an Asynch I/O model extension for simh.
In order to flesh-out and debug this design, I’ve also refactored several
devices to utilize this capability. Please read the attached
0readmeAsynchIO.txt file for concept details about the approach.
In order to make disk devices easy to implement (within or without the
AsynchIO framework), I’ve created a sim_disk.c library which is modeled
on the sim_tape.c library to generalize disk I/O like tape I/O is
generalized in sim_tape.c. This sim_disk.c library now provides that
natural place to implement support for various disk implementation formats
(just like sim_tape support several formats, and one day will be the place
to add direct physical tape access). The current sim_disk library provides
the framework for direct support of 3 different disk formats:
1) standard simh disk format
2) platform specific physical disk access
and 3) platform independent Virtual Disk format.
The Virtual Disk format is an implementation of the format described in
the ”Microsoft Virtual Hard Disk (VHD) Image Format Specification”. The
VHD specification is available for anyone to implement under the "Microsoft
Open Specification Promise" described at
http://www.microsoft.com/interop/osp/default.mspx.
The VHD implementation includes support for:
1) Fixed sized disks
2) Dynamically expanding disks
and 3) Differencing Disks.
Dynamically expanding disks don’t change their “Virtual Size”, but they
don’t consume disk space on the containing storage until the virtual
sectors in the disk are actually written to (i.e. an RA81 or RA92 VHD
with a VMS installed on it may initially only contain 30+ MB of files,
and the resulting VHD will be 30+ MB). The VHD format contains meta data
which describes the virtual device. Amongst this meta data is the simh
device type which the VHD was originally created as. This metadata is
therefore available whenever that VHD is attached to an emulated disk
device in the future so the device type & size can be automatically be
configured.
Sim_disk_attach is used by device emulations to attach a simh/vhd/raw
device to a simulated device. The following simh command switches
are used by the sim_disk_attach API:
-R Attach Read Only.
-E Must Exist (if not specified an attempt to create the
indicated virtual disk will be attempted).
-F Open the indicated disk container in a specific format
(default is to autodetect VHD defaulting to simh if the
indicated container is not a VHD).
-X When creating a VHD, create a fixed sized VHD (vs a
Dynamically expanding one).
-C Create a VHD and copy its contents from another disk
(simh, VHD, or RAW format).
-D Create a Differencing VHD (relative to an already
existing VHD disk)
Examples:
sim> show rq
RQ, address=20001468-2000146B*, no vector, 4 units
RQ0, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ1, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ2, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ3, 409KB, not attached, write enabled, RX50, autosize, SIMH format
sim> atta rq0 RA81.vhd
sim> show rq0
RQ0, 456MB, attached to RA81.vhd, write enabled, RA81, autosize, VHD format
sim> set rq2 ra92
sim> att rq2 -f vhd RA92.vhd
RQ2: creating new file
sim> sho rq2
RQ2, 1505MB, attached to RA92.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 12:57 PM 5,120 RA92.vhd
1 File(s) 5,120 bytes
0 Dir(s) 3,074,412,544 bytes free
sim> atta rq3 -c RA92-1.vhd RA92.vhd
sim> atta rq3 -c RA92-1.vhd RA92.vhd
RQ3: creating new virtual disk 'RA92-1.vhd'
RQ3: Copied 1505MB. 99% complete.
RQ3: Copied 1505MB. Done.
sim> sh rq3
RQ3, 1505MB, attached to RA92-1.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92*
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:12 PM 5,120 RA92-1.vhd
04/14/2011 12:58 PM 5,120 RA92.vhd
2 File(s) 10,240 bytes
0 Dir(s) 3,074,404,352 bytes free
sim> sho rq2
RQ2, 1505MB, not attached, write enabled, RA92, autosize, VHD format
sim> set rq2 ra81
sim> set rq2 noauto
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, VHD format
sim> set rq2 format=simh
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, SIMH format
sim> atta rq2 -c RA81-Copy.vhd VMS055.dsk
RQ2: creating new virtual disk 'RA81-Copy.vhd'
RQ2: Copied 456MB. 99% complete.
RQ2: Copied 456MB. Done.
sim> sho rq2
RQ2, 456MB, attached to RA81-Copy.vhd, write enabled, RA81, noautosize, VHD format
sim> det rq2
sim> ! dir RA81-Copy.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:22 PM 178,304,512 RA81-Copy.vhd
1 File(s) 178,304,512 bytes
0 Dir(s) 2,896,097,280 bytes free
sim> ! dir VMS055.dsk
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
03/08/2011 01:42 PM 403,663,872 VMS055.dsk
1 File(s) 403,663,872 bytes
0 Dir(s) 2,896,097,280 bytes free
sim>
The makefile now works for Linux and most Unix's. However, for Solaris
and MacOS, you must first export the OSTYPE environment variable:
> export OSTYPE
> make
Otherwise, you will get build errors.
1. New Features
1.1 3.8-0
1.1.1 SCP and Libraries
- BREAK, NOBREAK, and SHOW BREAK with no argument will set, clear, and
show (respectively) a breakpoint at the current PC.
1.1.2 GRI
- Added support for the GRI-99 processor.
1.1.3 HP2100
- Added support for the BACI terminal interface.
- Added support for RTE OS/VMA/EMA, SIGNAL, VIS firmware extensions.
1.1.4 Nova
- Added support for 64KW memory (implemented in third-party CPU's).
1.1.5 PDP-11
- Added support for DC11, RC11, KE11A, KG11A.
- Added modem control support for DL11.
- Added ASCII character support for all 8b devices.
1.2 3.8-1
1.2.1 SCP and libraries
- Added capability to set line connection order for terminal multiplexers.
1.2.2 HP2100
- Added support for 12620A/12936A privileged interrupt fence.
- Added support for 12792C eight-channel asynchronous multiplexer.
1.3 3.8-2
1.3.1 SCP and libraries
- Added line history capability for *nix hosts.
- Added "SHOW SHOW" and "SHOW <dev> SHOW" commands.
1.3.2 1401
- Added "no rewind" option to magtape boot.
1.3.3 PDP-11
- Added RD32 support to RQ
- Added debug support to RL
1.3.4 PDP-8
- Added FPP support (many thanks to Rick Murphy for debugging the code)
1.3.5 VAX-11/780
- Added AUTORESTART switch support, and VMS REBOOT command support
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
The makefile now works for Linux and most Unix's. Howevr, for Solaris
and MacOS, you must first export the OSTYPE environment variable:
> export OSTYPE
> make
Otherwise, you will get build errors.
1. New Features
1.1 3.8-0
1.1.1 SCP and Libraries
- BREAK, NOBREAK, and SHOW BREAK with no argument will set, clear, and
show (respectively) a breakpoint at the current PC.
1.1.2 GRI
- Added support for the GRI-99 processor.
1.1.3 HP2100
- Added support for the BACI terminal interface.
- Added support for RTE OS/VMA/EMA, SIGNAL, VIS firmware extensions.
1.1.4 Nova
- Added support for 64KW memory (implemented in third-party CPU's).
1.1.5 PDP-11
- Added support for DC11, RC11, KE11A, KG11A.
- Added modem control support for DL11.
- Added ASCII character support for all 8b devices.
1.2 3.8-1
1.2.1 SCP and libraries
- Added capability to set line connection order for terminal multiplexers.
1.2.2 HP2100
- Added support for 12620A/12936A privileged interrupt fence.
- Added support for 12792C eight-channel asynchronous multiplexer.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
