MICROCode Consulting Home
QP/M was the flagship product for MICROCode Consulting with countless copies sold, traded or provided free.  There are a lot of reasons why users chose QP/M although they may have had easy access to CP/M: Below are more details or go directly to downloads.  Given that last bullet, there was also a little controversy about QP/M you might enjoy reading.

If you want to try this out on your IBM-PC or compatible running, a Z-80 emulator is available.

Feature Details

Automatic time/date stamping of files using your computer's clock

How many times have the following situations occurred: "Six disks with MODEM.COM on them, which one is the LATEST version?" "When was the last time I updated my checkbook data files?" Time/date stamping of files solves all of these problems! QP/M features a time/date stamping system that transparently updates the time/date information whenever a file is created, written/updated, or achived. All you need is a real-time clock (either in your hardware or driven by software), and QP/M does the rest. Until now, the main choices for a time/date-featured system were CP/M Plus and TurboDOS. However, if you do not have lots of banked memory and banked money, QP/M is the logical choice.

Selectable common (default) drive/user area

Another feature of QP/M is a user-selectable common drive and/or common user area. Assume you use the default settings of QP/M (common drive is A, common user area is 0). Go to any drive and user area you wish, say B8. Run Word Processing or any other program from this new drive and user area; if QP/M cannot find the program in B8, it searches the common user area on the current drive (B0); if the program is not found in B0, it searches the common drive A (A0). The hierarchy is:
  1. current user area, current drive (read or write)
  2. common user area, current drive (read only)
  3. common user area, common drive (read only)
This drive/user search feature is not limited to just .COM files. Every file in the common drive/user area is accessible for read or write, independent of the current drive/user area. Now, suppose you open a file in the common drive/user area, then change either the current or common drive or user areas. No problem, QP/M always remembers where it originally retrieved that file. As long as the file remains open, QP/M will access the proper drive/user area. Both common drive and user can be set to another value or disabled by the user, if so desired.

Completely replaces BDOS and CCP

QP/M is not a simple patch or rework of CP/M - it is a totally new operating system. The standard QP/M package includes QDOS and QCP which entirely replace the original BDOS and CCP. Once you have installed QP/M, you can use your existing SYSGEN utility to replace the BDOS and CCP on any or all of your disks.

100% compatibility with CP/M 2.2

QP/M installs on EVERY CP/M machine...automatically! QP/M retains all of the features of CP/M 2.2 while adding a few of its own. Every program you have used with CP/M 2.2 will work with QP/M. Some even work better due to QP/M's speed and common drive/user capability. Also, you can use unstamped CP/M disks while running under QP/M, or you can use QP/M "stamped" disks while running under CP/M. Although QP/M cannot time/date stamp files on CP/M disks and CP/M is incapable of stamping QP/M disks, you will find no other differences.

Faster disk throughput

QP/M was carefully written to optimize disk operations. In conjunction with the powerful Z-80 instruction set, QP/M's compact code reads and writes to disk 10 to 15% faster than CP/M 2.2.

Efficient backup utility

QP/M offers a true backup capability both internally by tagging/untagging static/updated files and externally through the QBACKUP utility. If you have large capacity disks, you know how s-l-o-w disk copy routines can be. This is even more frustrating if only a couple of the many files on that disk actually changed. With QBACKUP, full disk copying is a thing of the past. Now, ONLY those files that have been changed since the last QBACKUP will be copied onto the backup disk.

Powerful new transient commands and system calls

QP/M more than doubles the transient commands familiar to CP/M users. These new commands are: Five new system calls are provided to assist the programmer in writing applications for QP/M:

Automatic disk relogging

With QP/M, <CTRL> + <C> is an item from the past! Whenever QP/M detects that a disk has been changed, a drive reset is performed automatically. "DOS error on x: R/O" is a message you will never see again.

Resides in same space as CP/M 2.2

Despite all of QP/M's features, it fits in the same space as your original CP/M 2.2 system. No need to give up more of your precious usable memory. Since system size on disk also remains the same, SYSGEN and similar utilities are fully compatible with QP/M.

Real-Time Clock Support

In order to have FULL time/date capability with QP/M, your system should support a real-time clock in either hardware or software. However, a real-time clock is NOT necessary to run QP/M. To interface with QP/M, a jump vector must be set up (anywhere in memory) to return the address of the "clock string" in register pair HL. The "clock string" is defined as a 6-byte string as follows:
HL +0 +1 +2 +3 +4 +5
  day month year hour min second
These values must be in binary with the time in 24-hour format. For example, March 17, 1986 at 6:12 p.m. would be expressed as:
HL +0 +1 +2 +3 +4 +5
  17 03 86 18 12 00
A new clock initialization utility (called TDCNFG.COM) is now provided to facilitate installation as well as a number of helpful clock modules in_source_code. This utility configures the specific clock initialization routine for any system which has: *Only usable on Xerox or BigBoard computers.

Multiple commands per line

With one version of QP/M, all the built-in commands are available. A second version of QP/M eliminates JUMP, GET and TOF while providing multiple commands per line. The separation character is "!", but is user configurable.


Package Version Date Size (bytes) Download time
(28.8K baud)
Click to
QP/M software 2.71 Sep 1986 82k 30sec qpmfiles.lbr
QP/M install and supplement guide 2.7 Dec 1985 251k 1min 32sec qpm27.pdf
QCP documentation 2.7 Dec 1985 241k 1min 29sec qcp27.pdf
QDOS documentation 2.7 Dec 1985 233k 1min 26sec qdos27.pdf
QP/M software + all documentation 2.7 Apr 2006 543k 3min 18sec qpm27.zip


Installation of this package entails running NULU on your CP/M system and extracting the files to drive A:, user 0.  Then, follow the directions given in the installation and supplements guide.  If you are running the MYZ80 emulator, a preconfigured QP/M operating system is available.

This is restricted for personal use software that is provided without any warranty whatsoever as described in the legacy Z-80 home page.