Home

#######  #####    ###            #####    ###   #     #           #####    ###     #####    ###            #####    ###   #     #
     #  #     #  #   #          #     #    #    ##   ##          #     #  #   #   #     #  #   #          #     #    #    ##   ##
    #   #     # #     #         #          #    # # # #          #     # #     #  #     # #     #         #          #    # # # #
   #     #####  #     #  #####   #####     #    #  #  #           #####  #     #   #####  #     #  #####   #####     #    #  #  #
  #     #     # #     #               #    #    #     #          #     # #     #  #     # #     #               #    #    #     #
 #      #     #  #   #          #     #    #    #     #          #     #  #   #   #     #  #   #          #     #    #    #     #
#######  #####    ###            #####    ###   #     #           #####    ###     #####    ###            #####    ###   #     #

Introduction:

• z80sim - Generic Z80/8080 CPU emulation with ICE like user interface, similar to hardware emulators from Zilog and Mostek and others
• z80asm - Z80 cross assembler to bootstrap a Z80 or 8080 system from an UNIX or Windows host
• cpmsim - Emulation of a complete system for running CP/M 1, CP/M 2, CPM 3 and MP/M 2 (bootable OS disk images included)
• altairsim - Emulation of an Altair 8800 system with 8080 or Z80 CPU, 64KB RAM, Cromemco Dazzler graphics, Tarbell SD disk controller with four 8" SD disk drives, front panel, 88SIO-2 connected to the host terminal, line printer connected to host file
• imsaisim - Emulation of an IMSAI 8080 system with 8080 or Z80 CPU, 64KB RAM, Cromemco Dazzler graphics, IMSAI FIF disk controller with four 8" SD disk drives, front panel, SIO-2 connected to the host terminal, line printer connected to host file
• cromemcosim - Emulation of a Cromemco Z-1 with Z80 CPU, 7 x 64KB banked memory, Cromemco Dazzler graphics, Cromemco 4FDC/16FDC disk controller with four 5.25" and 8" disk drives with support for DS and DD, front panel, UART on FDC card connected to the host terminal, additional TU-ART for more serial terminals and parallel printers

The 8080 emulation was added in 2014, for running vintage systems based on the Intel 8080 with their original software.

The original 1987 version could not be released public, because it included proprietary components from various companies, but for the Z80 core I keept the copyright. So an emulation of a virtual complete computer system capable of runnning CP/M 1, CP/M 2, CP/M 3 and MP/M 2 has been build, as an example for what can be done with this software. The Z80 cross assembler was used to bootstrap CP/M 2.2 on the system, for CP/M 3 and MP/M 2 the loader BIOS's were written on an UNIX host, final work then was done under CP/M 2.2 running on the emulated system.

This virtual computer system has then been used to rebuild CP/M 1, CP/M 2, CP/M 3 and MP/M 2 completely from the sources. Also example implementations of CP/NET have been build, to network the virtual systems with this very early implementation of RPC (remote procedure calls). Additional disk images with all sources, tools and build scripts are available for download.

The system also runs the UCSD p-System Versions I.4, I.5, II.0 and IV.0. Disk images for ready-to-run systems as well as sources to rebuild the Z80 version are available in the download section.

Features of the virtual cpmsim computer system:

• Lightning fast Zilog Z80 and Intel 8080 CPU, >1 GHz clock frequency doable on consumer PC's
• Clock generator tunable in 1MHz steps, helpful for video games or running vintage systems at realistic speed
• Up to 16MB RAM, banked into 256 segments with programmable MMU. Size of segments adjustable in 256 byte page increment
• 4 x IBM 8" SD compatible floppy disk drives
• 2 x 4MB harddisk drives
• 1 x 512MB harddisk drive
• 1 x serial console port connected to the CRT
• 5 x serial ports connected to TCP/IP ports for more MP/M terminals and CP/NET networking of multiple systems
• 1 x serial auxiliary port
• 1 x printer port
• 10ms interrupt timer, used for MP/M, Fuzix and other RTO's
• hardware clock, readonly, uses date and time information from host

The Z80 core then was used together with John Kichury's front panel library, to build exact emulations of the Altair 8800, IMSA 8080 and Cromemco Z-1 computer systems, that can be fully operated via the front panel similar to the original machines. The IMSAI 3D computer model build by John is really stunning, see the screenshots.

In 2014 an Intel 8080 emulation was added, so that these machines can run original vintage 8080 software, like the MITS BASIC interpreter written by Bill Gates, Paul Allen and Monte Davidoff.

The Z80, 8080 and I/O emulations are written in ANSI C, the front panel emulation in C++, for POSIX compatible Open Systems. Systems on which the sources are known to compile are:

• Apple OS X 10.9.2 and later
• OpenBSD, NetBSD, FreeBSD, PCBSD
• Linux x86 and x86-64 distributions like: Suse, Fedora Core, Debian
• Solaris 9/10/11 for SPARC and x86 with GNU C
• Microsoft Windows systems with Cygwin/CygwinX

Other native ports to Microsoft Windows have been done, links are in the download section.

Home page of Digital Research where everything began.

All Digital Research CP/M material included was taken from The Unofficial CP/M Web site, the license for this material can be read there.
Other commercial CP/M material included was taken from CP/M Commercial Software Archive.
Some user written tools were taken from the Oak CP/M archive.
Various programs from the Walnut Creek CP/M CD-ROM have been used too, an online copy is available here.
The UCSD p-System on 8" disk images is available at Bitsavers.
For documentation and software of the old machines you should visit Bitsavers anyway.

Quickstart to run the Digital Research OS's:

1. Download the z80pack source archive
2. Unpack the source archive in your home directory: tar xzvf z80pack-x.y.tgz
3. Compile the CP/M emulation:
   1. cd ~/z80pack-x.y/cpmsim/srcsim
   2. make -f Makefile.operating-system
   3. make -f Makefile.operating-system clean
4. Compile support programs, some are needed for the emulation:
   1. Releases before 1.15: cd ~/z80pack-x.y/cpmsim/srccpm2, Releases 1.15 and later: cd ~/z80pack-x.y/cpmsim/srctools
   2. make
   3. make clean
5. MAKE BACKUPS OF THE BOOTABLE DISK IMAGES:
   1. cd ~/z80pack-x.y/cpmsim/disks/library
   2. cp -p * ../backups
6. To run CP/M 2.2:
   1. cd ~/z80pack-x.y/cpmsim
   2. ./cpm2
   3. To leave the emulation type a:bye. This program executes a Z80 HALT instruction which terminates the emulator.
7. To run CP/M 3:
   1. cd ~/z80pack-x.y/cpmsim
   2. ./cpm3
   3. To leave the emulation type a:bye. This program executes a Z80 HALT instruction which terminates the emulator.
8. To run MP/M 2:
   1. cd ~/z80pack-x.y/cpmsim
   2. ./mpm
      This boots CP/M 2.2, the system tracks of the disk do not contain the mpmldr program. To boot MP/M type mpmldr which runs the loader under CP/M 2.2 and boots the MP/M 2 system from the disks.
   3. To leave the emulation type a:bye. This program executes a Z80 HALT instruction which terminates the emulation.
9. To exchange files between the UNIX host and the CP/M disk images download and install cpmtools. The emulator uses 8" SD disk drives as the first 4 drives, which also is the default used in cpmtools version 2.17 at the time of this writing. In case it changes sometime, the disk definition is:
   

   	diskdef ibm-3740
   	  seclen 128
   	  tracks 77
   	  sectrk 26
   	  blocksize 1024
   	  maxdir 64
   	  skew 6
   	  boottrk 2
   	  os p2dos
   	end
   

   Please note that the data tracks have a skew of 6, but the system tracks have a skew of 1, because I never implemented skews in the UNIX putsys programs. Using the correct skew made sense with Shugart floppy disk drives from 1976. Nowadays with SSD's used in personal computers transferring 500 MB/s and more the skew is only used for compatibility reasons.

   To access the 4 MB harddisk image of z80pack verify the following disk definition in /usr/local/share/diskdefs:
   

   	diskdef z80pack-hd
   	  seclen 128
   	  tracks 255
   	  sectrk 128
   	  blocksize 2048
   	  maxdir 1024
   	  skew 0
   	  boottrk 0
   	  os 2.2
   	end
   

   To access the 512 MB harddisk image verify this disk definition in /usr/local/share/diskdefs:
   

   	diskdef z80pack-hdb
   	  seclen 128
   	  tracks 256
   	  sectrk 16384
   	  blocksize 16384
   	  maxdir 8192
   	  skew 0
   	  boottrk 0
   	  os 2.2
   	end
   

   This definitions are included nowadys, if they are missing you need to add them. To access the 4 MB harddisk image (drives I: and J:) from the UNIX host always use the option -f z80pack-hd as in this example: cpmls -f z80pack-hd disks/drivei.cpm. Do not forget to use it, specially when copying files to the disk, without this option the harddisk image will be destroyed. Lets hope you made backup copies of the disk images.

   Same with the 512 MB drive P:, always use the option -f z80pack-hdb to access this drive file.

10. Start reading documentation, understanding the disk image layout under ~/z80pack-x.y/cpmsim/disks is essential.

Quickstart to run UCSD p-System:

1. Download the z80pack source archive
2. Unpack the source archive in your home directory: tar xzvf z80pack-x.y.tgz
3. Compile the CP/M emulation:
   1. cd ~/z80pack-x.y/cpmsim/srcsim
   2. make -f Makefile.operating-system
   3. make -f Makefile.operating-system clean
4. Compile support programs, some are needed for the emulation:
   1. Releases before 1.15: cd ~/z80pack-x.y/cpmsim/srccpm2, Releases 1.15 and later: cd ~/z80pack-x.y/cpmsim/srctools
   2. make
   3. make clean
5. Download the UCSD boot images
6. Unpack the archive in ~/z80pack-x.y/cpmsim: tar xzvf ucsd-ix.tgz
7. MAKE BACKUPS OF THE BOOTABLE DISK IMAGES:
   1. cd ~/z80pack-x.y/cpmsim/disks/library
   2. cp -p * ../backups
8. To run UCSD p-System:
   1. cd ~/z80pack-x.y/cpmsim
   2. ./ucsd-i4 or ./ucsd-i5 or ./ucsd-ii or ./ucsd-iv
   3. To leave the emulation first shutdown the UCSD p-System from main menu with the H command, then abort cpmsim with CTRL-\
9. To exchange files between the UNIX host and UCSD disk images download and install UCSD filesystem tools.

Downloads:

Documentation:

Support:

Copyright, License and all that stuff:

License in use for code written by me:

Copyright (c) 1987-2016 Udo Munk

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Bibliography:

1. Everything to know about the Z80 including original Zilog data sheets can be read here.
2. Digital Research manuals for CP/M 1, CP/M 2, CP/M 3, MP/M 2, assemblers, linkers and compilers are archived here.

Guides for z80pack:

Setting up z80pack to Create an Emulated CP/M System
Z80Pack CP/M Emulator and NZ-COM

If you wrote guides like these just let me know, so that it can be linked here.

More CP/M related links:

Informations about the UCSD p-System:

Other emulation projects based on z80pack:

If you are doing projects like these just let me know, so that your project web site can be linked here.

Other operating systems running on cpmsim:

Other UNIX Z80 emulations:

Informations about the Altair 8800:

Informations about the IMSAI 8080:

Informations about the Cromemco Z-1:

Home