Moving from Basic to CP/M


CP/M is a disk operation system, developed late 1970s by Digital Research, and was the first system to be portanble accross many systems sharing the Intel i8080 or Zilog z80 cpus. Only the BIOS had to be modified, and the system enabled intercompatability between computers, giving the computers access to thousands of software titles.

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By replacing just one module with the "512 RAM/ROM module", as shown above, it is possible to run the full CP/M operating system. Adding a "Compact Flash Drive" module enables storage of files, as shown below.

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There are two main roads running CP/M on the RC systems. 1) Using a boot loader, loading and running CP/M from a storage device like a compact flash or a hardisk drive module. There are two main options here; the first is provided by Spencer Owen (RFC2795 Ltd, Semachthemonkey) (www.rc2014.co.uk), and the second is the Small Computer Monitor (SCM) by Stephen Cousins (www.scc.me.uk).

The bootloader provided with many RC2014 systems, was originally developed Grant Searle and adaped to the RC2014 by Spencer Owen. The bootloader comes in many flavours, and is systems dependant. Usually, jumpers on the ROM module need to be set to select the right configuration.

The Small Computer Monitor (SCM) is a very flexible monitor program and boot loader. It also supports many different systems, and it also has its own development system; The Small Computer Workshop. The system can start up different software witout the need of switching ROM banks. The project is well documented.

2) Using a ROM based CP/M system like ROMWBW developed by Wayne Warthen (https://github.com/wwarthen/RomWBW)

The ROMWBW system is very good, it is continously beeing updated, it supports a range of CPUs, modules and systems. It is also possible to participate in developing and adapting the codebase. The ROMWBW, although flexible, is a selfcontained system, providing ROM and RAM disk, making it very robust. The project is well documented.