Change Log For V3.3

The change log for the previous version (V3.2) is here.

2 09-Mar-05 SCP: added ASSERT command (from Dave Bryan)


  • Fixed bugs in RESET for 11/70 (reported by Tim Chapman)
  • Fixed bug in SHOW MODEL (from Sergey Okhapkin)
  • Made SYSID variable for 11/70 (from Tim Chapman)
  • Fixed MBRK write case for 11/70 (from Tim Chapman)
  • RQ: added RA60, RA71, RA81 disks
  • RY: fixed bug in boot code (reported by Graham Toal)


  • Fixed IORETURN macro
  • PT: fixed bug in OCP '0001 (found by Philipp Hachtmann)
  • MT: fixed error reporting from OCP (found by Philipp Hachtmann)

HP2100 (from Dave Bryan)

  • Fixed missing MPCK on JRS target
  • Removed EXECUTE instruction (is NOP in actual microcode)
  • Fixed missing negative overflow renorm in StoreFP

I1401: fixed bug in LPT write line routine (reported by Van Snyder)

Interdata 32b: fixed branches to mask new PC (from Greg Johnson)


  • Fixed initial state of cpu_extmem
  • RQ: added RA60, RA71, RA81 disks
1 08-Jan-05 H316:
  • Fxed bug in DIV
  • TTY: fixed bug in SKS '104 (reported by Philipp Hachtmann)
  • TTY: fixed bug in SKS '504
  • Added reader/punch ASCII file support
  • Added Teletype reader/punch support
  • DP: fixed bug in skip on !seeking
  • MT: fixed bug in DMA/DMC support
  • LP: fixed bug in DMA/DMC support


  • Fixed DMA reset to clear alternate CTL flop (from Dave Bryan)
  • Fixed DMA reset to not clear control words (from Dave Bryan)
  • Fixed SBS, CBS, TBS to do virtual reads
  • Separated A/B from M[0/1], for DMA IO (from Dave Bryan)
  • Added SET CPU 21MX-M, 21MX-E (from Dave Brian)
  • Disabled TIMER/EXECUTE/DIAG instructions for 21MX-M (from Dave Bryan)
  • Added post-processor to maintain T/M consistency (from Dave Bryan)
  • DS: first release
  • LPS, LPT: added restart when set online, etc (from Dave Bryan)
  • LPS: col count for non-printing characters (from Dave Bryan)

IBM 1401: added address argument support (from Van Snyder)

Interdata: added magtape read-only file support


  • Fixed WAIT to work in all modes (from John Dundas)
  • TM, TS: added read-only file support

SDS 940: added magtape read-only file support

0 18-Nov-04 SCP and libraries:
  • Added -p (powerup) qualifier to RESET
  • Moved SET DEBUG under SET CONSOLE hierarchy
  • Added optional parameter value to SHOW command
  • Added output file option to SHOW command
  • Fixed comma-separated SET options (from Dave Bryan)
  • Fixed duplicate HELP displays with user-specified commands


  • Replicated RP register state per drive
  • Fixed TU to set FCE on short record
  • Fixed TU to return bit<15> in drive type
  • Fixed TU format specification, 1:0 are don't cares
  • Fixed TU handling of TMK status
  • Fixed TU handling of DONE, ATA at end of operation
  • Implemented TU write check


  • Separated RH Massbus adapter from RP controller
  • Added TU tape support
  • Added model emulation framework
  • Added model details
  • Replicated RP register state per drive
  • Fixed RQ, TQ to report correct controller type and stage 1 configuration flags on a Unibus system
  • Fixed HK CS2<output_ready> flag


  • Separated out CVAX-specific features from core instruction simulator
  • Implemented capability for CIS, octaword, compatibility mode instructions
  • Added instruction display and parse for compatibility mode
  • Added =n optional parameter to SHOW CPU HISTORY
  • Fixed parsing of indirect displacement modes in instruction input


  • Fixed  FP15 URFST to mask low 9b of fraction
  • Fixed FP15 exception PC setting

HP2100 (all changes and fixes from Dave Bryan)

  • CPU - moved MP into its own device; added MP option jumpers
  •     - modified DMA to allow disabling
  •     - modified SET CPU 2100/2116 to truncate memory > 32K
  •     - added -F switch to SET CPU to force memory truncation
  •     - modified WRU to be REG_HRO
  •     - added BRK and DEL to save console settings
  •     - fixed S-register behavior on 2116
  •     - fixed LIx/MIx behavior for DMA on 2116 and 2100
  •     - fixed LIx/MIx behavior for empty I/O card slots
  • DP - fixed enable/disable from either device
  •     - fixed ANY ERROR status for 12557A interface
  •     - fixed unattached drive status for 12557A interface
  •     - status cmd without prior STC DC now completes (12557A)
  •     - OTA/OTB CC on 13210A interface also does CLC CC
  •     - fixed RAR model
  •     - fixed seek check on 13210 if sector out of range
  • DQ - fixed enable/disable from either device
  •     - shortened xtime from 5 to 3 (drive avg 156KW/second)
  •     - fixed not ready/any error status
  •     - fixed RAR model
  • DR - provided protected tracks and "Writing Enabled" status bit
  •     - added "parity error" status return on writes for 12606
  •     - added track origin test for 12606
  •     - added SCP test for 12606
  •     - added "Sector Flag" status bit
  •     - added "Read Inhibit" status bit for 12606
  •     - added TRACKPROT modifier
  •     - fixed enable/disable from either device
  •     - fixed sector return in status word
  •     - fixed DMA last word write, incomplete sector fill value
  •     - fixed 12610 SFC operation
  •     - fixed current-sector determination
  • IPL - fixed enable/disable from either device
  •     - added fast/realistic timing
  •     - added debug printouts
  •     - fixed status returns for error conditions
  •     - fixed handling of non-printing characters
  •     - fixed handling of characters after column 80
  •     - improved timing model accuracy for RTE
  •     - fixed status returns for error conditions
  •     - fixed TOF handling so form remains on line 0
  • PTR - added paper tape loop mode, DIAG/READER modifiers to PTR
  •     - added PV_LEFT to PTR TRLLIM register
  • CLK - modified CLK to permit disable
  • SYS - fixed display of CCA/CCB/CCE instructions

IBM 1620, IBM 1401, Interdata 16b:

  • Added instruction history

Updated 30-Jan-2007 by Bob Supnik (simh AT trailing-edge DOT com - anti-spam encoded)