CP/M Plus on the ZX Spectrum Next
=================================


Introduction
============
The ZX Spectrum Next supports running CP/M Plus (also known as CP/M 3.0),
an operating system available from many microcomputers in the late 1970s and
early 1980s.

CP/M provides a command-line environment similar to DOS. A huge amount of
software was available for it, including programming languages & compilers,
word processors (such as the well-known WordStar), spreadsheets, databases,
utilities, text-based games and much more.

The Next runs CP/M Plus using a specially-written BIOS (basic input/output
system) which gives it a 24x80 text-based terminal supporting full colour.
It is run by selecting the CP/M option on the main menu.

You can run any software that runs on CP/M-80, CP/M 2.2, CP/M 3.0 or CP/M Plus,
but *not* CP/M-86 software (which requires an Intel x86 processor).

Please note that graphical applications requiring GSX cannot be used at the
moment, although support for these is under consideration. There is very
little software requiring GSX, however: most CP/M software was text-based.


Getting started
===============
Before you can use CP/M, you will need to download the following file from
the "The Unoffical CP/M Web site" which is officially licensed to distribute
the essential system files required:

        http://www.cpm.z80.de/download/cpm3bin_unix.zip

Once you have downloaded it, using a PC extract its contents into the
following directory on your Next's SD card:

        C:/NEXTZXOS/CPM

Once you have done this, restart your Next and choose "CP/M" from the main
menu. This will automatically set up your CP/M system drive (A:) and import
the system files. When it has completed and returned to the NextZXOS menu,
setup is complete. From now on, selecting "CP/M" from the main menu will
take you straight into CP/M.


Commands
========
CP/M is operated by typing commands at the prompt (A>). One of the most useful
commands is:

        DIR
        DIR A:

which shows a list of all the files on the current drive or the drive
specified. Initially you will just have drive A: available, but more can be
set up (drives A to P can be used) so that you can keep different programs
on different drives.

Any filename shown by DIR which ends in .COM is itself a command, and can be
executed at the prompt. You will have noticed there are a lot of .COM files
to try. Another useful one is:

        HELP

which provides help and information on all the standard commands and utilities
provided with CP/M.

There are also a number of commands specific to the ZX Spectrum Next. These
include:

        UPGRADE         Upgrades your installation of CP/M from the latest
                        version available on your SD card

        TERMINFO        An interactive demonstration of the terminal facilities
                        provided on the Next

        EXIT            Exits from CP/M and returns to NextZXOS

        COLOURS         Changes the colour scheme

        TERMSIZE        Changes the default terminal size (up to 32x80)

        IMPORT          Imports files from your NextZXOS C: drive (or other
                        FAT drives seen in the NextZXOS browser)

        EXPORT          Exports files to your NextZXOS C: drive (or other)

        ECHO            Sends text or ESCape sequences to the terminal

        NEXTREG         Views or changes ZX Spectrum Next hardware registers
                        (use at your own risk!)

Typing the name of these commands will give some more information on how to
use them.


Further information
===================
There is a lot to learn about CP/M, and a lot you can do with it. Some useful
places for further information are listed here.

http://www.cpm.z80.de/

Contains a lot of manuals, documentation and software. In particular,
the CP/M 3 User Guide, Command Summary and Programmers' Manual:

        http://www.cpm.z80.de/manuals/cpm3-usr.pdf
        http://www.cpm.z80.de/manuals/cpm3-cmd.pdf
        http://www.cpm.z80.de/manuals/cpm3-pgr.pdf

http://classiccmp.org/cpmarchives/

Links to many more useful sites, collections of software, manuals, magazines
and much more.


----
Garry Lancaster, 29th September 2019
