Change Log For V3.0

The change log for the previous version (V2.10) is here.

3 24-Oct-03 Ethernet library:  added support for VMS

All DECtapes:

  • Added off reel message
  • Simplified timing
  • Fixed value returned for read all of reverse checksum


  • Revised  RQ MB->LBN conversion for greater accuracy
  • Fixed bug with multiple RQ RAUSER drives

PDP-18b: added instruction history


  • Added support for TSC8-75 (ETOS) option
  • Added support for TD8E controller

Interdata 32b: added instruction history

2 12-Sep-03 SCP:
  • Fixed end of file bug in DEP, IDEP
  • Fixed error on trailing spaces in DEP, IDEP


  • Fixed system hang if continue after PTR error
  • Added PTR start/stop functionality
  • Added address switch functionality to PTR BOOT
  • Added multi-bank capability to LOAD


  • Fixed priorities in PDP-15 API (PI between 3 and 4)
  • Fixed sign handling in PDP-15 unsigned mul/div
  • Fixed bug in CAF, must clear API subsystem

IBM 1401:

  • Fixed tape read end-of-record handling based on real 1401
  • Added diagnostic read (space forward)

IBM 1620: fixed bug in immediate index add (found by Michael Short)

1 27-Jul-03 PDP-1:
  • Updated CPU  and peripherals to detect indefinite I/O wait
  • Fixed incorrect logical, missing activate, missing break in DRM
  • Fixed instruction decoding, overprinting in LPT
  • Updated RIM loader to work as "hardware"

PDP-10: Fixed read header function in RP

PDP-11, VAX: Fixed bug in set size function for RQ user-specified disk

18b PDP's:

  • Added EAE support to PDP-4
  • Added FP15 support to PDP-15
  • Added XVM support to PDP-15
  • Added "re-entrancy ECO" to PDP-15
  • Fixed CAF in PDP-7, PDP-9, PDP-15
  • Fixed bug in memory protection interaction with skip on PDP-9, PDP-15
  • Fixed overprinting in PDP-4 LPT
  • Fixed bug in set size routine in RF
  • Increased PTP TIME for PDP-15 operating systems timing sensitivities
  • Added hardware RIM Loader to PDP-7, PDP-9, PDP-15

PDP-8: Fixed bug in set size routine in DF, RF

Nova: Fixed bug in set size routine in DSK

AltairZ80: Fixed bug in real-time clock on Windows host

IBM 1130: Fixed bugs found by APL 1130

IBM 1401: Revised instruction fetch to model hardware more closely

HP2100: Fixed drum sizes, set size routine in DR

0 22-Jun-03 SCP and libraries:
  • Added ASSIGN/DEASSIGN logical names
  • Changed RESTORE to detach attached units
  • Fixed bug in SHOW CONNECTIONS
  • Added E11 and TPC format support to magtape library
  • Added extended file support

All magtapes: Added multi-format and extended file support

PDP-1: Fixed DECtape variable size interaction with RESTORE


  • Fixed integer overflow bug in CVTfi
  • Fixed multiple bugs in EMODf
  • Optimized byte and word DMA routines
  • Added calibrated delay to ROM reads (from Mark Pizzolato)
  • Fixed calibration problems in interval timer (from Mark Pizzolato)


  • Fixed bug in DP, DQ read status (13210A controller)
  • Fixed bug in DP, DQ seek completion


  • Fixed DECtape, DF32, and RF08 variable size interaction with RESTORE
  • Fixed bug in magtape SKTR instruction


  • Fixed bug in MMR1 update (found by Tim Stark)
  • Fixed DECtape variable size interaction with RESTORE
  • Corrected XQ interrupts on IE state transition (code by Tom Evans)
  • Added XQ interrupt clear on soft reset
  • Removed XQ interrupt when setting XL or RL (multiple people)
  • Added ability to split received packet into multiple buffers
  • Added explicit runt and giant packet processing


  • Fixed DECtape, RF09/RF15 variable size interaction with RESTORE
  • Fixed bug in magtape MTTR instruction

GRI-909: Fixed bug in PC queue pointer update

IBM 1401:

  • Fixed mnemonic, instruction lengths, and reverse scan length check bug for MCS
  • Fixed MCE bug, BS off by 1 if zero suppress
  • Fixed chaining bug, D lost if return to SCP
  • Fixed H branch, branch occurs after continue
  • Added check for invalid 8 character MCW, LCA
  • Fixed magtape load-mode read end of record response

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