# SIMH v4.0 - 19-01 Current [![Coverity Scan Build Status](https://scan.coverity.com/projects/11982/badge.svg)](https://scan.coverity.com/projects/simh) [![AppVeyor CI Build Status](https://ci.appveyor.com/api/projects/status/github/simh/simh)](https://ci.appveyor.com/project/simh/simh/history) ## Table of Contents: [WHAT'S NEW since the Open SIMH fork](#whats-new-since-the-open-simh-fork) [WHAT'S NEW since simh v3.9](#whats-new-since-simh-v39) . . [New Simulators](#new-simulators) . . [Simulator Front Panel API](#simulator-front-panel-api) . . [New Functionality](#new-functionality) . . . . [DDCMP Synchronous host physical device support - framer](#ddcmp-synchronous-host-physical-device-support---framer) . . . . [Remote Console Facility](#remote-console-facility) . . . . [VAX/PDP11 Enhancements](#vaxpdp11-enhancements) . . . . [PDP11 Specific Enhancements](#pdp11-specific-enhancements) . . . . [PDP10 Enhancements](#pdp10-enhancements) . . . . [SDS 940 Enhancements](#sds-940-enhancements) . . . . [Terminal Multiplexer additions](#terminal-multiplexer-additions) . . . . [Video Display Capabilities](#video-display-capabilities) . . . . [Asynchronous I/O](#asynchronous-io) . . . . [Clock/Timer Enhancements](#clocktimer-enhancements) . . . . [Ethernet Transport Enhancements](#ethernet-transport-enhancements) . . . . [Disk Extensions](#disk-extensions) . . . . [Embedded ROM support](#embedded-rom-support) . . . . [Control Flow](#control-flow) . . . . [Scriptable interactions with running simulators](#scriptable-interactions-with-running-simulators) . . . . [Help](#help) . . . . [Generic SCP support Clock Coscheduling as opposed to per simulator implementations](#generic-scp-support-clock-coscheduling-as-opposed-to-per-simulator-implementations) . . . . [New SCP Commands](#new-scp-commands) . . . . [Command Processing Enhancements](#command-processing-enhancements) . . . . . . [Environment variable insertion](#environment-variable-insertion) . . . . . . [Command aliases](#command-aliases) . . . . . . [Do command argument manipulation](#do-command-argument-manipulation) . . [Building and running a simulator](#building-and-running-a-simulator) . . . . [Use Prebuilt Windows Simulators](#use-prebuilt-windows-simulators) . . . . [Building simulators yourself](#building-simulators-yourself) . . . . . . [Linux/OSX other *nix platforms](#linuxosx-other-nix-platforms) . . . . . . . . [Build Dependencies](#build-dependencies) . . . . . . . . . . [OS X - Dependencies](#os-x---dependencies) . . . . . . . . . . [Linux - Dependencies](#linux---dependencies) . . . . . . [Windows](#windows) . . . . . . . . [Required related files](#required-related-files) . . . . . . . . [Visual Studio (Standard or Express) 2008, 2010, 2012, 2013 or Visual Studio Community 2015, 2017, 2019](#visual-studio-standard-or-express-2008-2010-2012-2013-or-visual-studio-community-2015-2017-2019) . . . . . . . . [MinGW32](#mingw32) . . . . . . [VMS](#vms) . . [Problem Reports](#problem-reports) ## WHAT'S NEW since the Open SIMH fork All Simulator updates on Open SIMH will be present in this repository, and any changes to the master branch code in this repository authored by anyone except Mark Pizzolato may be posted as pull requests on the Open simh repo. Simulator binaries for x86 Linus, x86 macOS, and Windows for all recent changes are available at https://github.com/simh/Development-Binaries ### Mark Pizzolato's changes only present in the simh/simh repo and not present in the Open SIMH repo: #### Visible changes to SCP (the simulator framework or command execution environment) - Add descriptive messages for cases when NOPARAM status is returned. - Avoid excessive DO command context lines when commands produce multiple lines of output. - Support has been added to allow for optional per device unit tests to exist and to invoke them at simulator startup. - Add support for generic bit field packing and unpacking during buffer copying. - Display count of units when all units are disabled. - Support to display all SCP visible filenames via relative paths and use those in SAVEd state. - ZAP command can be aborted by a Control-C. - Display current NOAUTOSIZE status in SHOW VERSION output. - Extend logical name support to include optional unique names for units as well as devices. - Add extended register sanity checks including duplicate name detection. Fixed simulator devices with duplicate register names. - Simulators with video devices that may be enabled, no longer disable the screen saver until the video display is presented. Optionally enabling or disabling the OS screen saver by an environment variable. - More readable output of SHOW | with variable sized DEVICE and UNIT names. - Automatic Cryllic Font detection in BESM6 simulator at runtime rather than build time. More relevant for distribution binaries. - Built-in command history and tab file name completion previously done by GPL readline now done by BSD licensed library available on all platforms (especially Windows). - Robust register sanity checking for all register definition macros. - When building on windows, the windows-build dependency libraries are automatically downloaded even if git is not available. - Extended video component version information displayed in SHOW VERSION output. - Add a global SET AUTOZAP command or per drive SET AUTOZAP which removes metadata from disk containers at detach time if the container has metadata. - DISKINFO command displays disk container metadata (if present) and container size along with detected file system information if a known file system type is present. - makefile builds which have potentially useful dependencies not found will prompt to install these components prior to building. MacOS Brew dependencies can be directly done from within the makefile. Other platforms (or package management systems) which require root access to install will display the appropriate package management commands and and exit. Support for macOS (HomeBrew and MacPorts), Linux (Ubuntu/Debian, RedHat/Fedora, Chimera), NetBSD, FreeBSD, OpenBSD. - SHOW VERSION show the host system type that build the runing simulator when it is not the same as the current host system. - Support for building simulators without built-in boot or ROM code when building with DONT_USE_INTERNAL_ROM is defined, but to automatically and transparently fetch the needed ROM or other boot code when it is needed. This is possibly useful for systems which don't want to distribute simulators with build-in binary code which may have unknown copyright status. - Reasonable output produced for all simulators from HELP BOOT. - Fix occasional hang of IBM1130 simulator while building with Visual Studio. - Building with the simh makefile defaults to compiling each source file separately and store the compiled result. This approach lends itself to quicker building for folks who are developing new simulators or new simulator modules. This was requested and discussed in #697. Invoking make with BUILD_SEPARATE=0 on the make command line or as an exported environment variable will disable separate compiles. - Building with the simh makefile defaults to displaying a summary of what is happening in each build step. Invoking make with QUIET=0 on the make command line or as an exported environment variable will cause the display of the full compiler or linker command being performed instead of the summary commands. - TAPE and SCSI libraries have been extended to fully support partial record reads of fixed sized records which may contain multiple records in recorded data. Images of this type are common for QIC tape archives generally available on bitsavers and elsewhere. Attach time checking on simulated QIC tape devices reports possible problems that may occur. - Appveyor CI/CD builds of all simulators for Linux, macOS and Windows platforms. - All the available simulator defined environment variables are documented in the help and sim_doc document file. - SET CONSOLE TELNET=CONNECT will start a telnet session to the simulator console in a separate window on all supported host systems. - Support for building on systems with the gameoftrees.org (got) source control system. - Frontpanel API improvements, document clarifications and bug fixes. - Added a SET CLOCK NOCALIBRATE mode. NOCALIBRATE mode allows all activity of a simulator run to occur with precisely consistent event timing. In this mode, every clock tick takes precisely the same number of instructions/cycles. Likewise, the polling activities for MUX or other poll oriented devices occurs after precisely the same number of instructions/cycles executed. As a consequence of this mode, no effort to align simulated clock ticks (and simulated access to wall clock time) is made. This mode will often be useful for running diagnostics which expect a particular relationship between perceived wall clock and instruction times. It might also be useful for running test scripts which may want to compare output of previous executions to to current execution or to compare execution on arbitrarily different host computers. It will also be useful when running under a host system debugger which might produce confusing results when various wall clock pause times when stopping at breakpoints. Additionally, consistent logical timing exists when simulator debug or instruction history is being recorded which normally would impact wall clock times. In NOCALIBRATE mode, the operator gets to specify the pseudo execution rate along with the base wall clock time that access to pseudo wall clock accesses returns. - All removable devices get detached on a media unload without regard to data access format (SIMH, VHD or RAW). - Various failing bugs in tape detach logic are fixed. - Clean building on Android Termux. - Proper line editing and tab filename completion behavior on all Unix and Windows platforms. - Simulators with video displays have a working SCREENSHOT command. - VHD Support for Differencing Disks has been corrected. - Attach time disk container copy support between dissimilar storage formats (VHD<->SIMH). Previously container copy operations were only supported between identical format containers (SIMH<->SIMH, and VHD<->VHD). - DISKINFO command provides more useful metadata information and file system verification with full support for VHD Differencing Disks. - Simulators which have instruction history support can now have SHOW HISTORY output be aborted by SIGINT (Control-C). - Device REGister variables have been extended to support double precision data. - More complete host system information displayed in SHOW VERSION output. - Simulator THROTTLING can only be enabled once per simulator run. This avoids potential errant behaviors when arbitrarily switching throttling settings. - EXAMINE memory commands will now produce minimal output that summarizes multiple successive locations with the same contents and may be aborted by SIGINT (Control-C). - Ethernet enhancements on all platforms and and much simplified platform support on macOS. - Almost all existing simulators have useful SET CONSOLE SPEED=nnn behaviors in both the bare console session as well as TELNET console sessions. - Simh global/startup configuration commands can be contained in the first of simh.ini found in: 1) The current working directory, 2) The User login directory, 3) The directory containing the simulator executable, 4) The ~/Library/Preferences directory, 5) The /Library/Preferences directory, or 6) The /etc directory. - Enhanced Ethernet functionality on macOS which leverages the OS provided vmnet capabilities. This is available on all intel and Apple Silicon macOS systems starting with Catalina (10.15) which was released in 2019. - SCP IF command supports RegEx comparisons. - Windows builds are supported running all versions of Microsoft Visual Studio, including the most recent VS2026. - All simulators build with full functionality and extended/simplified network support on illumos Open Indiana and Omni OS. #### All simulators build cleanly under OpenVMS on ia64 systems. #### Changes to the PDP-11 and VAX simulators also not in the Open SIMH repo - All VAXen: Correct HELP CPU to properly describe model specific LOAD options for ROM and NVRAM. - Add 2.11 BSD and NetBSD file system recognizers. - Add memory details and behavior description to the MicroVAX 3900 HELP CPU output. - Unibus and Qbus autoconfiguration disabling has been relaxed somewhat. Previously, any "SET ADDRESS= (or VECTOR=)" command would automatically disable autoconfigure for the rest of the simulator session. This behavior has been relaxed so that autoconfigure will only be disabled if the specified ADDRESS or VECTOR value is different from the value previously set by the initial autoconfigure. - Aggressive validation of Unibus and Qbus ADDRESS and VECTOR values prior to execution starting due to a BOOT command. - Fixed bug in devices that use sim_disk which deallocated a file transfer buffer on detach. - Metadata is implemented on all VAX and PDP11 disk devices when NOAUTOSIZE is not specified. - Full support for using disk containers with metadata between different system and device types where it makes sense. - VHD disk formats are available on all disk types (including floppy or DECtape devices). - Properly size RY drives which also don't have DEC144 - Properly name RQ extended units beyond the initial default units. - HELP CPU shows supported breakpoint types. - Add device support for DL11-C/DL11-D/DL11-E/DLV11-J in addition to the original KL11/DL11-A/DL11-B/DL11-E/DL11-F support. These new devices have different bus address ranges and can coexist with the original DL devices. The new devices are DLCJI and DLCJO and are managed identically to the original DLI and DLO devices. - All improvements and fixes to the PDP11 simulator from simh Version 3.12-3 release and beyond. - MicroVAX I has unsupported devices (TQ, TS, and VH) removed. - VAX750, VAX780, VAX8600 and PDP11 support additional Massbus disks on DEVICE RPB. - VAXStation I is now, once again, working. - MicroVAX I/VAXStation I has been enhanced to dynamically look for its secondary bootstrap program (SYSBOOT.EXE) from both [SYSEXE]SYSBOOT.EXE and [SYS0.SYSEXE]SYSBOOT.EXE. - PDP11 now has working support for RC and RF expandable platter based disk drives. - Properly set asynchronous interrupt latency in all VAX simulators. - MicroVAX I simulator boots from oldest MicroVMS media due to the addition of RQDX1 disk controller type. - MSCP Media-Id information and drive geometry information is available for all attached disk containers. - VAX Instruction history can be recorded to disk both for all instructions executed as well as every n instructions. - VAX Unibus simulators (780, 750, 730, 8600, 8200) run DEC supplied diagnostics at the speed of the original systems and also run the privileged instruction diagnostic that was supported on the original systems. - Reliable emulation of TU58 devices in PDP11 and Unibus VAX systems and consistent console TU58 on the VAX730 and VAX750. ### All relevant changes in Bob Supnik's simh v3.12-4 release have been merged into this repo ### Bill Beech has made significant enhancements and bug fixes to the SWTP simulators along with a new disk controller from Roberto Sancho Villa ### Patrick Linstruth has written a new Altair8800 simulator. ## WHAT'S NEW since simh v3.9 ### New Simulators #### Seth Morabito has implemented AT&T 3B2-400 and 3B2-700 simulators. #### Leonid Broukhis and Serge Vakulenko have implemented a simulator for the Soviet mainframe BESM-6 computer. #### Matt Burke has implemented new VAX model simulators: VAX-11/730 VAX-11/750 VAX 8200/8250 VAX 8600/8650 MicroVAX I & VAXstation I MicroVAX II & VAXstation II & VAXstation II/GPX rtVAX 1000 (or Industrial VAX 620) MicroVAX 2000 & VAXstation 2000 MicroVAX 3100 M10/M20 MicroVAX 3100 M10e/M20e InfoServer 100 InfoServer 150 VXT VAXstation 3100 M30 VAXstation 3100 M38 VAXstation 3100 M76 VAXstation 4000 VLC VAXstation 4000 M60 MicroVAX 3100 M80 InfoServer 1000 #### Howard Harte has implemented a Lincoln Labs TX-0 simulator. #### Gerardo Ospina has implemented a Manchester University SSEM (Small Scale Experimental Machine) simulator. #### Richard Cornwell has implemented a Burroughs B5500. #### Richard Cornwell has implemented the IBM 701, IBM 704, IBM 7010/1410, IBM 7070/7074, IBM 7080/702/705/7053 and IBM 7090/7094/709/704 simulators. #### Richard Cornwell has implemented the PDP6, PDP10-KA, PDP10-KI, PDP10-KL and PDP10-KS simulators. With the differences merely being some device name changes, the PDP10-KS should be compatible with Bob Supnik's original PDP10 simulator. #### Dave Bryan has implemented an HP-3000 Series III simulator. #### Updated HP2100 simulator from Dave Bryan. #### Updated AltairZ80 simulator from Peter Schorn. #### Sigma 5, 6 & 7 simulator from Bob Supnik #### Beta SAGE-II and PDQ-3 simulators from Holger Veit #### Intel Systems 8010 and 8020 simulators from Bill Beech #### CDC 1700 simulator from John Forecast #### Hans-�ke Lund has implemented an SCELBI (SCientic-ELectronics-BIology) simulator. #### IBM 650 simulator from Roberto Sancho Villa #### Jim Bevier has implemented a SEL32 simulator. #### Updates to the Unibus DUP & Qbus DPV device by Trevor Warwick Support for Phase V DECnet connections on VAX Unibus and Qbus systems and the addition of support for the DPV11 for Qbus VAX systems. ### New Host Platform support - HP-UX and AIX ### Simulator Front Panel API The sim_frontpanel API provides a programmatic interface to start and control any simulator without any special additions to the simulator code or changes to the SCP framework. ### New Functionality #### DDCMP Synchronous host physical device support - framer Paul Koning has implemented a USB hardware device which can interface transport DDCMP packets across a synchronous line to physical host systems with native synchronous devices or other simulators using framer devices. #### Remote Console Facility A new capability has been added which allows a TELNET Connection to a user designated port so that some out of band commands can be entered to manipulate and/or adjust a running simulator. The commands which enable and control this capability are SET REMOTE TELNET=port, SET REMOTE CONNECTIONS=n, SET REMOTE TIMEOUT=seconds, and SHOW REMOTE. The remote console facility has two modes of operation: 1) single command mode. and 2) multiple command mode. In single command mode you enter one command at a time and aren't concerned about what the simulated system is doing while you enter that command. The command is executed once you've hit return. In multiple command mode you initiate your activities by entering the WRU character (usually ^E). This will suspend the current simulator execution. You then enter commands as needed and when you are done you enter a CONTINUE command. While entering Multiple Command commands, if you fail to enter a complete command before the timeout (specified by "SET REMOTE TIMEOUT=seconds"), a CONTINUE command is automatically processed and simulation proceeds. A subset of normal simh commands are available for use in remote console sessions. The Single Command Mode commands are: ATTACH, DETACH, PWD, SHOW, DIR, LS, ECHO, HELP The Multiple Command Mode commands are: EXAMINE, IEXAMINE, DEPOSIT, EVALUATE, ATTACH, DETACH, ASSIGN, DEASSIGN, STEP, CONTINUE, PWD, SAVE, SET, SHOW, DIR, LS, ECHO, HELP A remote console session will close when an EOF character is entered (i.e. ^D or ^Z). #### VAX/PDP11 Enhancements RQ has new disk types: RC25, RCF25, RA80 RQ device has a settable controller type (RQDX3, UDA50, KLESI, RUX50) RQ disks default to Autosize without regard to disk type RQ disks on PDP11 can have RAUSER size beyond 2GB DMC11/DMR11 DDCMP DECnet device simulation. Up to 8 DMC devices are supported. Packet transport is via TCP or UDP connections. KDP11 on PDP11 for DECnet DUP11 on PDP11 for DECnet connectivity to talk to DMC, KDP or other DUP devices CH11 on PDP11 and VAX780 for Chaosnet (from Lars Brinkhoff) DZ on Unibus systems can have up to 256 ports (default of 32), on Qbus systems 128 port limit (default of 16). DZ devices optionally support full modem control (and port speed settings when connected to serial ports). TU58 device support for all PDP11 and VAX systems. DHU11 (device VH) on Unibus systems now has 16 ports per multiplexer. XQ devices (DEQNA, DELQA and DELQA-T) are bootable on Qbus PDP11 simulators XQ and XU devices (DEQNA, DELQA, DELQA-T, DEUNA and DELQA) devices can now directly communicate to a remote device via UDP (i.e. a built-in HECnet bridge). XQ and XU devices (DEQNA, DELQA, DELQA-T, DEUNA and DELQA) devices can now optionally throttle outgoing packets which is useful when communicating with legacy systems (real hardware) on a local LAN which can easily get over run when packets arrive too fast. MicroVAX 3900 has QVSS (VCB01) board available. MicroVAX 3900 and MicroVAX II have SET CPU AUTOBOOT option MicroVAX 3900 has a SET CPU MODEL=(MicroVAX|VAXserver|VAXstation) command to change between system types MicroVAX I has a SET CPU MODEL=(MicroVAX|VAXSTATION) command to change between system types MicroVAX II has a SET CPU MODEL=(MicroVAX|VAXSTATION) command to change between system types #### PDP11 Specific Enhancements ROM (from Lars Brinkhoff) I/O page ROM support NG (from Lars Brinkhoff) Knight vector display DAZ (from Lars Brinkhoff) Dazzle Dart Input device #### PDP10 Enhancements KDP11 (from Timothe Litt) for DECnet connectivity to simulators with DMC, DUP or KDP devices DMR11 for DECnet connectivity to simulators with DMC, DUP or KDP devices on TOPS10. CH11 (from Lars Brinkhoff) Chaosnet interface. #### SDS 940 Enhancements Support for SDS internal ASCII character encoding during display and data entry. Allow breakpoints to be qualified by normal, monitor or user mode. Fix CPU, RAD, MUX and I/O bugs that prevented SDS Time Share System Monitor and Executive from executing properly. #### Terminal Multiplexer additions Added support for TCP connections using IPv4 and/or IPv6. Logging - Traffic going out individual lines can be optionally logged to files Buffering - Traffic going to a multiplexor (or Console) line can optionally be buffered while a telnet session is not connected and the buffered contents will be sent out a newly connecting telnet session. This allows a user to review what may have happened before they connect to that session. Serial Port support based on work by J David Bryan and Holger Veit Serial Console Support Separate TCP listening ports per line Outgoing connections per line (virtual Null Modem cable). Packet sending and reception semantics for simulated network device support using either TCP or UDP transport. Input character rates reflect the natural character arrival time based on the line speed. #### Video Display Capabilities Added support for monochrome and color displays with optional keyboards and mice. The VAXstation QVSS device (VCB01) and QDSS device (VCB02) simulations use these capabilities. Host platforms which have libSDL2 available can leverage this functionality. #### Asynchronous I/O * Disk and Tape I/O can be asynchronous. Asynchronous support exists for pdp11_rq, pdp11_rp and pdp11_tq devices (used by VAX and PDP11 simulators). * Multiplexer I/O (Telnet and/or Serial) can be asynchronous. Asynchronous support exists for console I/O and most multiplexer devices. (Still experimental - not currently by default) #### Clock/Timer Enhancements * Asynchronous clocks ticks exist to better support modern processors that have variable clock speeds. The initial clock calibration model presumed a constant simulated instruction execution rate. Modern processors have variable processor speeds which breaks this key assumption. * Strategies to make up for missed clock ticks are now available (independent of asynchronous tick generation). These strategies generate catch-up clock ticks to keep the simulator passage of time consistent with wall clock time. Simulator time while idling or throttling is now consistent. Reasonable idling behavior is now possible without requiring that the host system clock tick be 10ms or less. * Simulator writers have access to timing services and explicit wall clock delays where appropriate. #### Ethernet Transport Enhancements * UDP packet transport. Direct simulator connections to HECnet can be made without running a local packet bridge program. * NAT packet transport. Simulators which only speak TCP/IP (No DECnet) and want to communicate with their host systems and/or directly to the Internet can use NAT packet transport. This also works for WiFi connected host systems. * Packet Transmission Throttling. When connected to a LAN which has legacy network adapters (DEQNA, DEUNA) on legacy systems, it is very easy for a simulated system to overrun the receiving capacity of the older systems. Throttling of simulated traffic delivered to the LAN can be used to mitigate this problem. * Reliable MAC address conflict detection. * Automatic unique default MAC address assignment. #### Disk Extensions RAW Disk Access (including CDROM) Virtual Disk Container files, including differencing disks File System type detection to accurately autosize disks. Recognized file systems are: DEC ODS1, DEC ODS2, DEC RT11, DEC RSTS, DEC RSX11, Ultrix Partitions, ISO 9660, BSD 2.11 partitions and NetBSD partitions #### Tape Extensions AWS format tape support TAR format tape support ANSI-VMS, ANSI-RSX11, ANSI-RSTS, ANSI-RT11 format tape support #### Embedded ROM support Simulators which have boot commands which load constant files as part of booting have those files imbedded into the simulator executable. The imbedded files are used if the normal boot file isn't found when the simulator boots. Specific examples are: VAX (MicroVAX 3900 - ka655x.bin) VAX8600 (VAX 8600 - vmb.exe) VAX780 (VAX 11/780 - vmb.exe) VAX750 (VAX 11/750 - vmb.exe, ka750_old.bin, ka750_new.bin), VAX730 (VAX 11/730 - vmb.exe) VAX610 (MicroVAX I - ka610.bin) VAX620 (rtVAX 1000 - ka620.bin) VAX630 (MicroVAX II - ka630.bin) #### Control Flow The following extensions to the SCP command language without affecting prior behavior: GOTO