weems%umass-cs%csnet-relay@sri-unix.UUCP (11/24/83)
From: Charles Weems <weems%umass-cs@csnet-relay>
Someone recently requested info on compatibility of the Columbia MPC
with the IBM PC. I've had a Columbia MPC with a hard disk for about 4
months now and have run into very few compatibility problems. Several
magazines have reviewed the entire field of compatibles over the last
year and have consistently rated the Columbia as the most compatible.
The only true compatibility problems stem from differences in the low
level ROM subroutines (which have to be different to avoid copyright
infringement). Very little software on the market makes use of these
routines directly -- those that do are trying to squeeze out the last
bit of speed from graphics operations in most cases. This will be even
less of a problem in the future for two reasons: 1) Doing so excludes sales
to the ever growing compatibles market. 2) Even IBM has warned software
companies not to count on future versions of the ROM having the same
calling points and characteristics.
Most of my problems with the Columbia have been identical to those of
the PC-XT. Many software vendors use a copy protection scheme that
prohibits the user from putting a copy on the hard disk. I could, of course,
run the software from the floppy but my strategy with the hard disk has
been to keep the software there and data on the floppy (to eliminate the
need for frequent full backups). The floppy based Columbia (or the floppy
based IBM) don't have these problems. Some software simply won't run on
a hard disk system (some versions of the UCSD p-system, for example), but
again the IBM PC-XT is no different than the Columbia in that regard.
My only hardware compatibility problem stems from the fact that the
Columbia comes with a full set of I/O ports on board. This means that
I have to use an external modem (which I actually prefer) and that I have
to be careful when buying multifunction cards that it's possible to
disable their I/O ports to avoid conflicts.
The last area of incompatibility is in the operating system. Columbia
did not have DOS 2.0 ready when I bought my MPC, so I can't run software
that requires it. They now have DOS 2.0 available and I expect to get the
copy I ordered within a few days. The old DOS was fully compatible with
that of the IBM DOS at the same release level.
In summary, the only true incompatibilities are the low level ROM and
the full set of I/O ports. (The latter is easy enough to run up against on
the IBM if you try to add more than one multifunction card.) I've had no
hardware trouble with it and have been reasonably satisfied with the $3000
dollars worth of software that comes with it. I have seen Columbias run
DBase II (2.4), Edix and Wordix, Multiplan, IBM Pascal and Microsoft's
Flight Simulator without problems.
chip weems