CP/M-86 Kernel

Synopsis

The goal of this project is to provide an out-of-the-box CP/M-86 1.1 kernel (BIOS, BDOS and CCP) that incorporates all existing patches plus the capacity to run on modern hardware and virtualization. A distribution of the CP/M-86 OS is also provided fully patched.

The distribution also packages digital research assembler tools and various basic environments.

• visual y2k support and tod replacement (https://github.com/tsupplis/cpm86-hacking)
• AT support
• resilience to bios limits for video display

This is a raw dump right now with a way to compile the kernel starting from dissassembled sources. The compilation requires the (cross-development environment for CP/M-86)[https://github.com/tsupplis/cpm86-crossdev]

The CP/M-86 kernels (8088 and V20 Mixed 8080/8088 with CP/M-80 compatibility) for the V20 MBC are also produced. The sources of the bioses used are available at:

• https://hackaday.io/project/170924-v20-mbc-a-v20-8088-8080-cpu-homebrew-computer

The 3 kernels use the same BDOS and CCP components.

Playing with CP/M-86

To test, the PCE emulator and cpmtools are needed. PCE can be found at http://www.hampa.ch/pce/. the floppy images released also work with qemu.

Alternatively, you can use the excellent V20 MBC available at:

• https://hackaday.io/project/170924-v20-mbc-a-v20-8088-8080-cpu-homebrew-computer
• https://shop.mcjohn.it/en/diy-kit

• Patched CP/M-86 running in the PCE Emulator

• CP/M-86 BIOS Setup 1.2

• CP/M-86 Disk Maintenance 1.2

Distribution

A full 160K single phase distribution is provided on 4 disks. The compiled cpm.sys file is also provided standalone.

• cpm86-1.img: bootable core CP/M-86
• cpm86-at-1.img: bootable core CP/M-86 with AT-compatible clock
• cpm86-2.img: assembler CP/M-86 tools
• cpm86-3.img: digital research dev tools
• cpm86-4.img: basic development (microsoft basic, personal basic, cbasic)

The kernels built and delivered standalone as part of the release are:

• cpm86.sys (ibm pc xt)
• cpmv20.sys (MBC V20, 8088 mode)
• cpm816.sys (MBC V20, mixed 8080/8088 mode with CP/M-80 compatibility)

The CP/M-86 OS contains the following commands are in the original distribution:

• asm86.cmd
• assign.cmd
• config.cmd
• ddt86.cmd
• help.cmd
• print.cmd
• function.cmd
• gencmd.cmd
• stat.cmd

The CP/M-86 OS is enhanced with the following patched or updated components:

• help.hlp (more complete content)
• dskmaint.cmd (updated from 1.0 to version 1.2)
• setup.cmd (updated from 1.0 to version 1.2)
• hdmaint.cmd (updated from 1.0 to version 1.1)
• ed.cmd (patched following dr recommendation)
• gendef.cmd (patched following dr recommendation)
• pip.cmd (patched following dr recommendation)
• submit.cmd (patched following dr recommendation)
• mform.cmd (patched to avoid interactive question)
• tod.cmd (complete rewrite at https://github.com/tsupplis/cpm86-hacking)
• atinit.cmd (sync up RTC clock and bios if clock available, cf https://github.com/tsupplis/cpm86-hacking)

also the images produced from the blank image have a boot loader terminating with 55AA allowing emulators like qemu to load CP/M-86 properly. Beware, if the image is formatted using dskmaint.cmd, the signature will not be added. A small boot fix will be added later.

Pedigree

The main source for it is: http://www.cpm.z80.de

• Baseline: http://www.cpm.z80.de/download/cpm86src.zip
• Baseline: http://www.cpm.z80.de/download/cpmdev.zip
• Patching Source: http://www.cpm.z80.de/download/cpm86ann.zip
• Patching Source: http://www.cpm.z80.de/download/cpm86bug.zip

To be continued...