CP/M and the Year 2000
- I am not an official spokesman for any organisation that owns or sells
CP/M. All information on these pages is the result of tests made by me or
other third parties. It may be incorrect. I accept no responsibility for
dire consequences caused by the use of information or programs on this page;
use them at your own risk!
- If I say a program or operating system is 2000 compliant, it only means
that my tests have failed to detect any flaws. On the other hand, if I say
that something is not 2000 compliant, I'm probably on to something :-)
- This is still very much a work in progress; if a particular CP/M
version is marked as unknown, and you have Year 2000 information on it,
please let me know.
- This page is limited to discussion of the operating system. If you have a
hardware clock, you will also need to check its compliance; similarly, you
need to check any applications that you are using.
- Some application patches can be found at
The version numbers listed below are the internal numbers used by the BDOS;
under CP/M-86, these do not necessarily correspond to the version numbers used
by other parts of the system.
To determine your BDOS version number, download and run
VER80.COM for 8-bit systems or
VER86.CMD for 16-bit.
Links to files
Downloadable fixes for known Year 2000 problems.
The OS makes no use of dates and so is fully Year 2000 compliant.
You will still need to check any applications you use.
The original Digital Research CP/M 2 makes no use of dates.
However, several third-party BDOSes have been produced, which
behave like CP/M 2 but also include time and date functionality:
NovaDOS and SUPRBDOS are derivatives of P2DOS and the P2DOS
information also applies to them.
- Z80DOS itself is 2000 compliant. Its date utility
(TIMEZD12.COM) will not display dates past 2000 correctly, but
such dates can be entered.
- DOS+ itself is 2000 compliant. Its date utility
(TIME.COM) will accept dates past 2000, if they are entered
explicitly as four digits.
- P2DOS is 2000 compliant, and it is supplied with an
excellent date utility that is also 2000 compliant. A version
of this date utility suitable for use in Z80DOS, DOS+ and CP/M 3
is available on the fixes page.
CP/M 3.x (CP/M Plus)
The CP/M Plus BDOS is 2000 compliant, but the utilities
DATE, DIR and SHOW are not. See
the fixes page for information on
obtaining updated versions of these programs.
BDOS 2.x (CP/M-86 v1.1)
The BDOS itself includes no date functions. However, the BIOS
displays the current date on the screen; Year 2000 patches for this
are available at the Unofficial
CP/M Website, DOWNLOAD >> CP/M-86 >> PATCHES
BDOS 4.x (DOSPLUS; Personal CP/M-86 v2.0/2; CP/M-86 Plus)
The BDOS itself is Year 2000 compliant. The PCP/M-86 v2.0/2
and CP/M-86 Plus utilities (DIR.CMD; SDIR.CMD; SHOW.CMD; DATE.CMD)
will not allow entry or display of dates after 2000. The DOSPLUS
equivalent (COMMAND.COM) will.