541 lines
24 KiB
Text
541 lines
24 KiB
Text
SIMH/HP 3000 RELEASE NOTES
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==========================
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Last update: 2016-09-20
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This file documents the release history of the Hewlett-Packard 3000 simulator.
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The SIMH project does not issue discrete releases. Instead, the current
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simulator code base is available at:
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https://github.com/simh/simh
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...and may be downloaded at any time. A code snapshot is identified by the "git
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commit ID" that is displayed by the simulator welcome banner.
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Therefore, HP 3000 releases are simply documentation checkpoints that describe
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the changes that have occurred since the last checkpoint. Generally, a release
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is written when one or more major changes have been incorporated. Minor bug
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fixes will be available immediately but only noted as part of the next release
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document.
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===================
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General Information
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===================
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The simulator passes the HP 32230 offline diagnostic suite with some expected
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failures due to unimplemented features. For example, the disc diagnostic
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error-correction logic tests and the tape diagnostic CRCC and LRCC tests fail,
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as these features are not supported. However, all features that are required
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for MPE operation pass their respective diagnostic tests.
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The simulator has been tested with MPE-V/R version E.01.00. Specifically:
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- MPE can be RELOADed to generate a new disc-based system from a FOS tape.
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- MPE can be COOLSTARTed to run from a previously generated disc.
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- The MPE system console operates (by default) through the simulation console,
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and additional sessions may be connected to the ATC via Telnet or host
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serial ports.
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- MPE FOS programs (EDITOR, QUERY) and SUBSYS programs (SPL, BASIC, BASICOMP)
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run properly.
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- The SYSDUMP program produces a valid tape image, and the system may be
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COLDSTARTed from it.
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- The operator and system manager can be logged in and out, and MPE can be
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SHUTDOWN through to a HALT 17.
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The user's manual for the simulator is provided in Microsoft Word format in the
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"doc" subdirectory of the code base snapshot downloaded from the github site. A
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PDF version of the same manual is available at:
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http://alum.mit.edu/www/jdbryan/hp3000_doc.pdf
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A preconfigured MPE-V/R disc image containing the Fundamental Operating Software
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(FOS), selected SUBSYS language processors (BASIC, BASICOMP, COBOL, COBOLII,
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FORTRAN, PASCAL, RPG, and SPL), and example programs is available from Bitsavers
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at:
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http://www.bitsavers.org/bits/HP/HP_3000/
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The archive contains instructions and simulator command files that allow
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ready-to-run operation.
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Manuals describing MPE operation are also available from Bitsavers at:
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http://www.bitsavers.org/pdf/hp/3000/
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HP created MPE-V/R-specific manuals. However, very few of them survive. In
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general, the MPE-IV manuals describe a subset of MPE-V/R commands, whereas the
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MPE-V/E manuals describe a superset. Relying on the MPE-IV manuals and the
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online help available within MPE for those commands that do not appear in the
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manuals is perhaps the best compromise.
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-----------------------
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Bugs in MPE V/R E.01.00
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-----------------------
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Testing during simulator development revealed the presence of several bugs in
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the MPE version used:
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- After a cold load from tape (COLDSTART/RELOAD/UPDATE), if a non-HP terminal
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such as the simulation console is used as the system console, MPE prints DATE
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(M/D/Y)? and then WED, NOV 1, 1972, 12:00 AM, as though RETURN had been
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entered, but it wasn't. If an HP terminal emulator is used instead, MPE
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waits for the user to enter the date before proceeding.
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The problem is incorrect coding in the SPEEDSENSE procedure in module
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INITIAL. As a result, the console baud rate is set to an invalid value, so
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console reads fail. The resulting zero-length read is interpreted as though
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RETURN had been entered.
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This is MPE V/R SSB KPR Number 5000187104, "Foreign devices as SIII system
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consoles do not work correctly on V/R." HP issued a patch for this, but it
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does not seem to have survived. A simple workaround is to set local ENQ/ACK
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processing on ATC channel 0 (SET ATCD0 LOCALACK) when the system console is
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not an HP terminal. This is the default setting, so the bug only manifests
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itself when SET ATCD0 REMOTEACK is done before booting. An alternate
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workaround that does not depend on the ATC setting is to set memory location
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01.112247 to octal value 021360. This changes the "LOAD P+22,I,X"
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instruction at that location to "LDI 360" to set the detected speed to 2400
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baud unconditionally.
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- If a SHUTDOWN is performed while a logon read is pending on the system
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console, e.g., by pressing RETURN to obtain the colon prompt after logging
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OPERATOR.SYS off, the expected "ALL JOBS LOGGED OFF" message does not print.
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Instead, the first few characters of the message (which begins with the
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current time) are printed, followed as expected by SHUT and a HALT %17. If
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no read is pending, either because RETURN was not pressed before entering the
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SHUTDOWN command or because the read timed out, the message is printed
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normally.
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The problem is that while the message is being send to the ATC character-by-
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character, the I/O abort issued to cancel the logon read also cancels the
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message write. The timing is such that only the first few characters of the
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message are printed before the rest of the output is cancelled.
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No SSB KPR has been located, but a later MPE version inserts an ABORTIO call
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for the system console immediately before logging all sessions off. This
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clears any logon read that might exist, and therefore an abort will not be
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performed after the "ALL JOBS LOGGED OFF" message is output. It is
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impossible to patch memory to add this call, so the only workarounds when
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shutting down are to avoid requesting the logon prompt, wait until the logon
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timeout expires (nominally two minutes), log on and then back off again,
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enter "=ABORTIO 20" to abort the read before entering SHUTDOWN, or accept
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that the message will be truncated. The only consequence of this bug is the
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partial message; MPE shuts down properly otherwise, so it may be safely
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ignored.
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- After a RELOAD, running DPAN4.PUB.SYS produces a "CODE SEGMENT TOO LARGE
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(LOAD ERR 33)" error. This is because MPE defaults to an 8K code segment
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size limit, and DPAN4 has three segments between 8K and 12K in size. If the
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limit is subsequently raised via a SYSDUMP and COLDSTART reconfiguration,
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running DPAN4 produces a "FILE IS NOT A VALID PROGRAM FILE" error. However,
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if the reconfiguration is done before running DPAN4, it will run properly
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thereafter.
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The problem is that MPE incorrectly modifies the executable file's Segment
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Transfer Tables when it encounters a code segment that is larger than the
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configured limit. This leaves the file in an inconsistent state, leading to
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the "NOT A VALID PROGRAM FILE" message after reconfiguration to raise the
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segment size limit. If the limit is raised before running DPAN4, the file is
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internally consistent when the STTs are patched, and each segment's load
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succeeds, allowing the program to run.
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No SSB KPR has been located, but a later MPE version ensures that code
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segment size aborts occur before any of the STTs are modified, so the program
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file remains internally consistent. A memory patch is impossible, but
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workarounds are to increase the code segment limit before running DPAN4 and
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to restore DPAN4.PUB.SYS from the FOS tape if it has been damaged.
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=====================
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Release 3, 2016-09-20
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=====================
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This release of the HP 3000 simulator adds the following features:
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- Cold dump is now available. Entering the DUMP command simulates pressing
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the ENABLE and DUMP front panel buttons. The contents of main memory are
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written to an attached magnetic tape in a format suitable for analyzing with
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the DPAN4 program. The new SET CPU DUMPDEV and SET CPU DUMPCTL options
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specify the default device number and control byte for the dump.
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- The SHOW LP VFU command now displays the VFU channel definitions in
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addition to the VFU tape title.
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- The POWER FAIL and POWER RESTORE commands have been added to simulate losing
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and regaining system power.
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- The SET CPU ARS and SET CPU NOARS options have been added to simulate the
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power-fail/auto-restart switch on the back of the system front panel.
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- The CMD instruction has been implemented and passes section 4 of the CPU
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diagnostic.
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--------------------
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Implementation Notes
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--------------------
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- In hardware, MPE execution cannot continue after a DUMP is performed. This
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is because a cold dump performs an I/O reset before writing the contents of
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memory to the tape, and this clears the I/O device controllers to their
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initial power-on states. However, execution can be continued if a SAVE is
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done to record the simulator state before the dump and a RESTORE is done
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after the dump completes. This permits taking a "snapshot" of MPE operation
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without disturbing MPE.
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----------
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Bugs Fixed
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----------
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1. PROBLEM: An SIO READ or WRITE order with a 4K count displays as zero.
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VERSION: Release 2
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OBSERVATION: SIO READ and WRITE orders define bits 4-15 as the negative
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word count of the transfer. If bits 4-15 are zero, the transfer is 4096
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words long. However, an EXAMINE -I command displays the word count as
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zero.
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CAUSE: The display value is being calculated incorrectly.
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RESOLUTION: Modify "IOCW_COUNT" (hp3000_cpu_ims.h) to sign-extend the
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12-bit count correctly to 16 bits, and modify "fprint_order" (hp3000_sys.c)
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to negate the values to display the counts as positive. Also modify
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"mpx_interface" (hp3000_mpx.c) to display the correct count in the debug
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trace for the DREADSTB operation.
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STATUS: Fixed in Release 3.
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2. PROBLEM: An I/O reset does not clear a pending external interrupt.
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VERSION: Release 2
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OBSERVATION: A cold load begins with a CPU reset and an I/O reset. A cold
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dump begins with an I/O reset only to preserve the CPU state for the dump
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operation. The external interrupt flip-flop on the IOP is cleared by an
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I/O reset, which should clear the external interrupt bit in the CPX1
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register. However, this does not occur, causing the interrupt generated by
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placing the tape drive online to be misinterpreted as the SIO program
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completion interrupt. Because the SIO pointer is not set as expected, the
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cold dump microcode assumes that a tape error occurred and performs a
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retry. This writes an erase gap at the beginning of the tape but otherwise
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produces a valid tape.
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CAUSE: Oversight.
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RESOLUTION: Add a new "iop_reset" routine (hp3000_iop.c) that is called
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during an I/O reset and that clears the external interrupt bit of the CPX1
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register.
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STATUS: Fixed in Release 3.
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3. PROBLEM: RESTORE of a file SAVEd with a different executable may abort the
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simulator.
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VERSION: Release 2
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OBSERVATION: Entering SAVE to save the simulator state on an executable
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compiled with one set of compiler options or compiler version and then
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entering RESTORE to restore the state on an executable compiled with a
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different set of compiler options or compiler version succeeds. However,
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attempting to resume execution results in an access exception.
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CAUSE: The simulator's internal Device Information Blocks contain pointers
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to the devices' I/O interface handlers, which are saved as part of the DIB
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structure in the simulator state file. When restoring the state, the
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interface handler pointers are restored. However, the addresses of one or
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more routines may have changed, due to differing memory layouts, so the
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restored values are no longer correct. If they are not, and I/O is
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performed to the affected device(s), control transfers to an invalid code
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location.
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RESOLUTION: Modify hp3000_io.h to add a new REG_DIB macro that defines the
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register entries needed to save the DIB state, and modify hp3000_atc.c,
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hp3000_clk.c, hp3000_ds.c, hp3000_lp.c, hp3000_mpx.c, hp3000_ms.c, and
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hp3000_scmb.c to change the REG entries referencing the DIB structures to
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use the REG_DIB macro.
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STATUS: Fixed in Release 3.
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4. PROBLEM: The LOAD command does not report "Cold load complete".
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VERSION: Release 2
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OBSERVATION: The LOAD command should report success after completion of a
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cold load operation, but it doesn't. Instead, the SCP prompt returns with
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no indication of whether the command succeeded or failed. Using the
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equivalent BOOT CPU command does print the expected "Cold load complete"
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message.
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CAUSE: The "Cold load complete" message is printed by the simulator's
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"fprint_stopped" routine that is called via the "sim_vm_fprint_stopped"
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pointer from the "run_cmd_message" routine in SCP. The latter is invoked
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via the "message" field of the command table. The LOAD, DUMP, and POWER
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commands all invoke "sim_instr" via "run_cmd" but do not specify routine
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pointers for their message fields, so no completion messages are reported.
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RESOLUTION: Modify "one_time_init" (hp3000_sys.c) to set the "message"
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fields of the LOAD, DUMP, and POWER commands to point at the same routine
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as is used by the system "CONTINUE" command.
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STATUS: Fixed in Release 3.
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5. PROBLEM: RESTOREing with the ATCD attached cancels active line services.
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VERSION: Release 2
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OBSERVATION: Doing a SAVE while the ATCD has line services scheduled,
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e.g., while outputting characters, and then following immediately with a
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RESTORE cancels the line services. For example, after a SAVE, a SHOW QUEUE
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command prints:
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HP 3000 event queue status, time = 907247803
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CLK at 0
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ATCD unit 0 at 241
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CPU at 27917
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ATCD unit 16 at 27918
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DS unit 8 at 612615
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Entering RESTORE and then SHOW QUEUE prints:
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HP 3000 event queue status, time = 907247803
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CLK at 0
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CPU at 27917
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ATCD unit 16 at 27918
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DS unit 8 at 612615
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Note that ATCD unit 0 is no longer scheduled.
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CAUSE: The "atcd_detach" routine is called during RESTORE if the listening
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port is currently attached in preparation for reattaching to the port
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specified in the SAVE file. The routine detaches the listening port and
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then cancels each line to terminate any transfers in progress. This is
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appropriate for DETACH ATCD and DETACH ALL, but not for RESTORE, as the
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terminal channels have already been rescheduled as indicated in the SAVE
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file, and canceling them hangs the channels.
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RESOLUTION: Modify "atcd_detach" (hp3000_atc.c) to skip the channel
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termination loop if the SIM_SW_REST flag is set to indicate a RESTORE in
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progress.
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STATUS: Fixed in Release 3.
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=====================
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Release 2, 2016-07-05
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=====================
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This release of the HP 3000 simulator adds the following device simulation:
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- 30209A Line Printer Controller with One 2607/13/17/18 Line Printer
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The simulation supports the use of custom VFU tape images, as well as the
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built-in HP-standard VFU tape. The simulated device name is "LP". The full set
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of configurable options is detailed in a new section of the HP 3000 Simulator
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User's Guide.
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In addition, the preconfigured MPE-V/R disc image has been updated to add the
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following features:
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- The MPE cold load command files attach the line printer to the "lp.txt"
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output file and specify the "-n" option to clear the file before use.
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- Preinstalled User-Defined Commands (UDCs) provide access to the COBOL 74
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compiler with the MPE-V/E :COBOLII, :COBOLIIPREP, and :COBOLIIGO commands,
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and to the COBOL 85 compiler with :COBOLIIX, :COBOLIIXPREP, and :COBOLIIXGO.
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However, see the implementation note below.
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--------------------
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Implementation Notes
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--------------------
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- MPE requires a line printer, so it is recommended that the MPE startup
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simulator command file include an ATTACH LP <filename> command to load paper
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into the printer before cold loading. If the printer is not attached, it
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will appear to MPE to be out of paper.
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- The line printer terminates each print line with an HP-standard CR/LF pair.
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If the output file is to be retained as a text file on a Unix system, removal
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of the carriage returns, e.g., via the "dos2unix" utility, may be desirable.
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- The simulator currently does not provide the HP 32234A COBOL II firmware
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instructions, so programs generated by the COBOLII compiler will abort at run
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time with an "ILLEGAL INSTRUCTION" error. Programs generated by the COBOL
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compiler do not use these instructions and therefore are not affected.
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----------
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Bugs Fixed
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----------
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1. PROBLEM: The effective address of a byte pointer with a negative index is
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calculated incorrectly.
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VERSION: Release 1
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OBSERVATION: Defining a :WELCOME message in MPE appears to work, but when
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the next logon attempts to print the message, an infinite number of CRLFs
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are printed instead.
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CAUSE: The welcome message is stored in an extra data segment. The format
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for each message line is a line length stored in the lower byte of the word
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preceding the message string. The code defines BYTE POINTER NEXTLINE and
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points NEXTLINE to the first message character. The line length is set
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with NEXTLINE(-1) := IOCOUNT. This generates a LOAD <IOCOUNT> ; LDXN 1 ;
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STB <NEXTLINE>,I,X sequence.
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In the "cpu_ea" routine, the indexing adds the X register value (-1) to the
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byte pointer (NEXTLINE). This causes an overflow that is not masked to 16
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bits. For a word access, this displacement is added to the base register
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and then masked to 16 bits, which gives the correct value. However, for
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byte accesses, the displacement is divided by 2 and then added, and the sum
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is masked. Dividing by 2 shifts the overflow bit into the MSB, causing the
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addition result to be off by 32K. The STB goes to the wrong location, the
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original zero in the length byte location is retained, and when the welcome
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message is printed, a zero-length line is printed, and the byte pointer is
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incremented by zero, so the null line is printed forever.
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RESOLUTION: Modify "cpu_ea" (hp3000_cpu.c) to mask indexed displacements
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to 16 bits after adding the X register value.
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STATUS: Fixed in Release 2.
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2. PROBLEM: An SMSK instruction may clear the interrupt mask flip-flop of a
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device that specifies that it is should be "always enabled."
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VERSION: Release 1
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OBSERVATION: If the TOS word is zero, an SMSK instruction will clear the
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interrupt mask flip-flop of a device whose mask jumper is set to "E"
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(always enabled).
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CAUSE: In response to a DSETMASK signal, device interfaces set their
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interrupt mask flip-flops by "anding" the incoming data word with the
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interrupt mask jumper setting. The jumper setting value for "always
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enabled" is %177777, which sets the mask flip-flop in all cases, except
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when the data word is zero.
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RESOLUTION: Modify hp3000_atc.c, hp3000_ds.c, and hp3000_ms.c to set their
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mask flip-flops unconditionally if the jumper setting is "E".
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STATUS: Fixed in Release 2.
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3. PROBLEM: The "SET <dev> INTMASK=<n>" command sets the wrong bit in the
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device interface's interrupt mask jumper setting.
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VERSION: Release 1
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OBSERVATION: The interrupt mask jumper on a device interface is set by
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specifying the mask bit number in a "SET <dev> INTMASK=<n>" command. This
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sets a bit in the device's interrupt mask jumper word corresponding to the
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bit number requested. However, the bit numbering is incorrect; setting the
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jumper for bit 15, for example, sets bit 0 of the jumper word. Therefore,
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the interface's mask flip-flop is not set as expected when an SMSK
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instruction is executed.
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CAUSE: The bit numbers were counted from the wrong end of the word.
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RESOLUTION: Modify "hp_set_dib" and "hp_show_dib" (hp3000_sys.c) to number
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the bits from the MSB instead of the LSB.
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STATUS: Fixed in Release 2.
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4. PROBLEM: The Multiplexer Channel is not generating the ACKSR signal
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correctly.
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VERSION: Release 1
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OBSERVATION: The line printer controller hangs when an SIO chained write
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is performed. The first programmed write completes normally, but the
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|
second does not start. The channel is waiting for a service request that
|
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does not occur.
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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).
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|
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RESOLUTION: Modify "mpx_service" (hp3000_mpx.c) to test the correct I/O
|
|
order in State A.
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|
|
|
STATUS: Fixed in Release 2.
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|
|
|
|
|
|
|
=====================
|
|
Release 1, 2016-03-07
|
|
=====================
|
|
|
|
This is the initial release of the HP 3000 simulator. The following devices are
|
|
currently simulated:
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|
|
|
- 30003B Series III computer with up to 1024 KW of memory
|
|
- 30003B I/O Processor
|
|
- 30036B Multiplexer Channel
|
|
- 30030C Selector Channel
|
|
- 30033A Selector Channel Maintenance Board
|
|
- 30032B Asynchronous Terminal Controller data interface
|
|
- 30061B Asynchronous Terminal Controller control interface
|
|
- 30135A System Clock/Fault Logging Interface
|
|
- 30215A Tape Controller with four 7970B/E drives
|
|
- 30229B Disc Controller with eight 7905/7906/7920/7925 drives
|
|
|
|
The "HP 3000 Simulator User's Guide" manual describes the configuration and
|
|
operation of each of these devices in detail.
|
|
|
|
|
|
--------------------
|
|
Implementation Notes
|
|
--------------------
|
|
|
|
- IMPORTANT: There is no line printer simulation. MPE cannot be configured to
|
|
run without a printer; attempting to delete LDEV 6 produces "ERROR #115
|
|
UNDEFINED CLASS LP USED AS OUTPUT DEVICE", and class LP cannot be deleted.
|
|
With LDEV 6 present, MPE will boot and run, but doing, e.g., :STOPSPOOL 6
|
|
causes "NON-RESPONDING DRT #14" and "SYSTEM FAILURE #201" when the printer
|
|
doesn't respond. Entering :OUTFENCE 14 at the console operator's session
|
|
immediately after bootup is a workaround. The LP simulator should be present
|
|
in the next release.
|
|
|
|
- The CPU is a hybrid of the Series II instruction set microcode and the Series
|
|
III memory size and hardware behavior, because the Series III microcode is
|
|
not available.
|
|
|
|
- The CPU is currently missing a few "difficult" instructions (the CMD
|
|
instruction, the Series II LOCK and UNLK instructions, and the entire
|
|
Extended Instruction Set). Although the EIS is not present, MPE has a
|
|
software emulator for these instructions that is invoked transparently by the
|
|
Unimplemented Instruction traps that occur when attempted execution of EIS
|
|
instructions occurs.
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|
|
|
- The main memory Fault Logging Interface section of the 30135A is currently
|
|
not simulated. Although fault-control memory was standard on the Series II
|
|
and later, the memory fault logger is smart enough to realize that the FLI is
|
|
not there, so MPE will run without it.
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|
|
|
- Symbolic entry of CPU instructions, CPU status, and I/O instructions are not
|
|
currently supported.
|