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  CP/M Plus (v3.1)  
This page is about the CP/M operating system for the C128 produced by Commodore Business Machines (CBM). For some reason, various idiots refer to the C128 implementation as CP/M version 3.0. However, there has never been a CP/M v3.0!!! The closest thing is a related product called MP/M of version 3.0. If you don't believe me, you can ask CP/M (call BDOS function 49 and examine version at offset 5) and it will tell you that CP/M Plus is version 3.1. So in your face retards!
More than a few people doubt me on this subject.  Welcome to the club of disbelievers!  As I understand it, CBM licensed and adapted the system from Digital Research, Incorporated.  DRI typically used either the term "CP/M Plus" or "CP/M 3" in their documentation (and not something more specific like 3.0, 3.1, etc.)  I suspect (but can not prove) that CBM marketing choose the inaccurate term CP/M v3.0.  This is because their marketing departement was known to make false claims as if they were fact (for example, Bil Herd talks about how marketing claimed the C128 is 100% compatible with the C64).
I am not a CP/M expert, so you might want to check out this web site (historically, this web site by John Elliot).  He provides a horde of technical information, but a simple sentence (by him) says it best...

CP/M came in three main versions; 1.4, 2.2 and 3.1...

Besides CP/M for 8-bit systems (such as the C128 discussed here), he also has plenty of info about CP/M for other processors, such as for the Intel 80x86 and Motorola 680x0.  By the way, I've tried to find more relevant / "official" documents, unfortunately 50%~75% of the links regarding CP/M on the web today seem to be broken.  It is fading away!
  CP/M Disk Image  
Some folks on the C128 Alive Forums were asking for a disk image of CP/M for the C128. Apparently other images floating around on the Internet have "problems" ... so for the benefit of the Commodore community, I'm providing my personal version of the CP/M Plus system in D71 format available for download.  This is neither a highly hacked version nor the 'official' version released by CBM.  Rather, it is the 'final' version released by CBM with patches for year 2000+ (Y2K patches)... I use and recommend it as a good compromise between compatibility and functionality.
Note: if you are using a device that does not support fast-serial protocol (like some SD2IEC devices) then CP/M will consider the device to be a C1541 disk drive!  This limits you to a meager 170 KiByte of storage capacity and extremely slow disk access (unless both your C128 and your device support JiffyDOS).  Because CP/M is a very disk-intensive system, the slow speed will make the system virtually unusable (unless you have an REU and copy all your files there).
CP/M was designed to run on multiple computer systems. At the time there were many different disk formats in use by various companies. Most CP/M systems only support the disk format of the parent company (in this case, CBM). However CBM produced its own line of successful computers which had disk formats quite different from those used by other CP/M computers.

Fortunately, CBM included support in their version of CP/M on the C128 for 'native' CBM disk formats and with a new (at the time) disk drive (C1571) it could also read some of the most popular 'foreign' disk formats. In particular, formats used by Kaypro and Osborne.  Shortly after the release of the C128 computer, CBM released another multi-format-capable disk drive called the C1581.  Note these drives were not in direct competition.  The C1571 used 5.25 inch floppy disks while the C1581 used the newer 3.5 inch floppy disks.

However, there are many formats not supported by C128's CP/M. Luckly, the CP/M operating system is quite flexible and a program called JUGGLER 128 was released that will let a C128 computer read almost every possible floppy disk format (with a supported disk drive, like C1571 or C1581).

A member of C128 Alive! forums asked for this Juggler program on a CBM standard disk image (.D64) and so I made one and have posted it for the benefit of the entire Commodore community.  You can download a raw D64 disk image of Juggler or a ZIP file including D64 disk image and information in TXT format. The software is copyright (c) 1988, 1996 Herne Data Systems Ltd. Please Contact Me if you are the copyright holder and wish this content removed from this site.
  More History  
CP/M was created by Gary Kildall who went on to found Digital Research Incorporated (DRI).  According to the Corporate Histories Collection at the Computer History Museum,  CP/M v2.2 became an "industry standard" in February 1980 (whatever that means), and CP/M 3 was released in 1983 (month not specified).  The C128 shipped with CP/M 3 from its beginning (in 1985); at least 3 seperate revisions exist and were provided by CBM as two 5.25 single-sided disks on the front and back of a "flippy-disk":
  • Initial Release (August 1985)
  • Second Release (December 1985, adds support for modem and REU, removes 2nd printer)
  • Third Release (May 1987, adds support for 1581)
The C128 System Guide (included with the computer) contains a mail-in form (at least in the USA) to obtain the full DRI documentation (I believe 3 printed manuals) and additional software for CP/M 3 (on 5.25-inch disks).  I am not sure how / if CBM distrubted a 3.5-inch disk version; however the third release can format such a disk and install a bootable operating system on one.
Eventually, DRI was sold to Novel in 1991.  Which in turn sold the rights to Caldera Systems in 1996.  It seems Caldera won a lawsuit against Micrsoft in 2000 regarding MS-DOS / Windows "theft" of CP/M code... not that it helped them survive!  Caldera went on to change its name to The SCO Group in 2002.  Which in turn filed for bankruptcy in 2007... however it seems it was still a legal entity as late as 2009.  I don't know who, if anybody, owns the rights to CP/M nowadays.  Anyway, for more CP/M info particular to the C128, I suggest going to Herne's CP/M page.

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Subpages (2): Disk Format Games