PROBLEM: Attempting to LOAD after a RESTORE of an MPE session aborts
the simulator with an "integer division by zero" exception.
OBSERVATION: Stopping the simulator during an idle MPE session,
saving the state to a file, exiting, restarting, restoring, and
attempting to perform a cold load aborts with a "divide by 0" error.
CAUSE: The "clk_update_counter" routine in hp3000_clk.c is called as
part of the instruction postlude to update the clock's counter
register. A calculation divides the elapsed time since the last tick
by the clock unit's "wait" value. The developer's manual stated that
this field is saved and restored automatically, but this is not true.
When the simulator is restarted, the "wait" field is initially zero.
If "clk_update_counter" is called before the clock's event service
routine resets the value, the calculation will divide by zero, which
causes the abort.
RESOLUTION: Modify "clk_reg" (hp3000_clk.c) to preset the unit wait
field with the MPE clock resolution value.
- This release of the HP 3000 simulator adds the following device simulation:
- 30209A Line Printer Controller with One 2607/13/17/18 Line Printer
The simulation supports the use of custom VFU tape images, as well as the
built-in HP-standard VFU tape. The simulated device name is "LP". The full set
of configurable options is detailed in a new section of the HP 3000 Simulator
User's Guide.
In addition, the preconfigured MPE-V/R disc image has been updated to add the
following features:
- The MPE cold load command files attach the line printer to the "lp.txt"
output file and specify the "-n" option to clear the file before use.
- Preinstalled User-Defined Commands (UDCs) provide access to the COBOL 74
compiler with the MPE-V/E :COBOLII, :COBOLIIPREP, and :COBOLIIGO commands,
and to the COBOL 85 compiler with :COBOLIIX, :COBOLIIXPREP, and :COBOLIIXGO.
However, see the implementation note below.
--------------------
Implementation Notes
--------------------
- MPE requires a line printer, so it is recommended that the MPE startup
simulator command file include an ATTACH LP <filename> command to load paper
into the printer before cold loading. If the printer is not attached, it
will appear to MPE to be out of paper.
- The line printer terminates each print line with an HP-standard CR/LF pair.
If the output file is to be retained as a text file on a Unix system, removal
of the carriage returns, e.g., via the "dos2unix" utility, may be desirable.
- The simulator currently does not provide the HP 32234A COBOL II firmware
instructions, so programs generated by the COBOLII compiler will abort at run
time with an "ILLEGAL INSTRUCTION" error. Programs generated by the COBOL
compiler do not use these instructions and therefore are not affected.
----------
Bugs Fixed
----------
1. PROBLEM: The effective address of a byte pointer with a negative index is
calculated incorrectly.
VERSION: Release 1
OBSERVATION: Defining a :WELCOME message in MPE appears to work, but when
the next logon attempts to print the message, an infinite number of CRLFs
are printed instead.
CAUSE: The welcome message is stored in an extra data segment. The format
for each message line is a line length stored in the lower byte of the word
preceding the message string. The code defines BYTE POINTER NEXTLINE and
points NEXTLINE to the first message character. The line length is set
with NEXTLINE(-1) := IOCOUNT. This generates a LOAD <IOCOUNT> ; LDXN 1 ;
STB <NEXTLINE>,I,X sequence.
In the "cpu_ea" routine, the indexing adds the X register value (-1) to the
byte pointer (NEXTLINE). This causes an overflow that is not masked to 16
bits. For a word access, this displacement is added to the base register
and then masked to 16 bits, which gives the correct value. However, for
byte accesses, the displacement is divided by 2 and then added, and the sum
is masked. Dividing by 2 shifts the overflow bit into the MSB, causing the
addition result to be off by 32K. The STB goes to the wrong location, the
original zero in the length byte location is retained, and when the welcome
message is printed, a zero-length line is printed, and the byte pointer is
incremented by zero, so the null line is printed forever.
RESOLUTION: Modify "cpu_ea" (hp3000_cpu.c) to mask indexed displacements
to 16 bits after adding the X register value.
STATUS: Fixed in Release 2.
2. PROBLEM: An SMSK instruction may clear the interrupt mask flip-flop of a
device that specifies that it is should be "always enabled."
VERSION: Release 1
OBSERVATION: If the TOS word is zero, an SMSK instruction will clear the
interrupt mask flip-flop of a device whose mask jumper is set to "E"
(always enabled).
CAUSE: In response to a DSETMASK signal, device interfaces set their
interrupt mask flip-flops by "anding" the incoming data word with the
interrupt mask jumper setting. The jumper setting value for "always
enabled" is %177777, which sets the mask flip-flop in all cases, except
when the data word is zero.
RESOLUTION: Modify hp3000_atc.c, hp3000_ds.c, and hp3000_ms.c to set their
mask flip-flops unconditionally if the jumper setting is "E".
STATUS: Fixed in Release 2.
3. PROBLEM: The "SET <dev> INTMASK=<n>" command sets the wrong bit in the
device interface's interrupt mask jumper setting.
VERSION: Release 1
OBSERVATION: The interrupt mask jumper on a device interface is set by
specifying the mask bit number in a "SET <dev> INTMASK=<n>" command. This
sets a bit in the device's interrupt mask jumper word corresponding to the
bit number requested. However, the bit numbering is incorrect; setting the
jumper for bit 15, for example, sets bit 0 of the jumper word. Therefore,
the interface's mask flip-flop is not set as expected when an SMSK
instruction is executed.
CAUSE: The bit numbers were counted from the wrong end of the word.
RESOLUTION: Modify "hp_set_dib" and "hp_show_dib" (hp3000_sys.c) to number
the bits from the MSB instead of the LSB.
STATUS: Fixed in Release 2.
4. PROBLEM: The Multiplexer Channel is not generating the ACKSR signal
correctly.
VERSION: Release 1
OBSERVATION: The line printer controller hangs when an SIO chained write
is performed. The first programmed write completes normally, but the
second does not start. The channel is waiting for a service request that
does not occur.
CAUSE: The service request from the last write of the first block transfer
is being cleared by an ACKSR generated by the Multiplexer Channel when it
performs the IOCW fetch in State A for the second write request. The
channel should omit this ACKSR when the previous I/O order was a chained
read or write. However, the simulator is testing the order just fetched
(Write) instead of the order that has just completed (Write Chained).
RESOLUTION: Modify "mpx_service" (hp3000_mpx.c) to test the correct I/O
order in State A.
STATUS: Fixed in Release 2.
- 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.
When PNG support is available, both .png and .bmp screenshots can be
generated based on the file extension specified by the user on the SCREENSHOT
command. If no extension is specified, then a PNG format screenshot will be
produced.
Reworked all priority adjustment code to leverage a new
sim_os_set_thread_priority API which is coded to use pthreads or OS
priority adjustment APIs as necessary.
The new RUN/GO command syntax supports a stop criteria.
There are two forms of stop criteria:
1) A normal breakpoint (which exists only until it is encountered)
2) A user specified output string is emitted by the simulated system.
Command syntax is:
RUN|GO {START-PC-VALUE} {UNTIL breakpoint|"output-string"}
Multiple rules with the same match string are processed in the order the EXPECT
commands are entered. NOEXPECT will remove all pending EXPECT rules which
have the match string provided on the NOEXPECT line.
Compilation under Cygwin with gcc 5.3.0 - missing const gave rise to
incompatible pointer type warning, and _eth_get_system_id for _WIN32
was included under a conditional for either _WIN32 or __CYGWIN__
and later redefined for !_WIN32
sim> SET XQ MAC=aa:bb:cc:dd:ee:ff{/bits}{>filespec}
where:
- all of the aa:bb:cc:dd:ee:ff values must be hex digits
- bits is the number of bits which are to be taken from the supplied
MAC aa:bb:cc:dd:ee:ff with legal values from 16 to 48 and a default
of 48 bits.
- filespec specifies a file which contains the MAC address to be used
and if it doesn't exist an appropriate generated address will be stored
in this file and a subsequent SET MAC invocation specifying the same
file will use the value stored in the file rather than generating a new
MAC.
As discussed in #317
The project migration process from VS2008 to VS2015 doesn't bring in
project/solution wide migration compile defines that are introduced in
Visual Studio Community's migration which adds _USING_V110_SDK71.
This affects source modules which explicitly don't inherit project wide
defines. The compile of pthread.c (in various projects) is such a case.
Multiple devices sharing the same pool of fixed and/or vector addresses
need to properly account for earlier devices that may have already consumed
available fixed addresses or vectors.
Recent enhancements to idle/infinite loop detection generalized handling
of detecting 'loop to self' cases. This was done without considering that
some instructions have side effects (i.e. change other state like the stack
pointer) and thus aren't merely loop to self cases.
This problem was reported in #315
Also changed how interrupts are generated. When a line changes state
and interrupt should be generated. Once this is read no further
notification should be posted. If no characters are written in a
record the DTC should transition to IDLE state.
