🚀 go-pugleaf

In article <1991Jan25.002213.3888@unhd.unh.edu>, jwm712@unhd.unh.edu (Jonathan W Miner) writes:
> I have a friend who wants to be able to convert his DEC Rainbow to
> an IBM clone.  What products are available, and what are their limitations?
> 
The short answer is to sell the Rainbow and get an IBM clone.

Short of that, some measure of IBM compatibility can be achieved
by running the MS-DOS 3.1 from Suitable Solutions (now defunct, at
least as far as Rainbow support is concerned.  I'm not sure if 
anyplace else still sells MS-DOS 3.1 - maybe the Rainbow User's
Group).  Revision B of MS-DOS 3.1 would be the one to get, if you
can get hold of it.  This customization of MS-DOS for the Rainbow
allows some IBM programs to run OK.

Secondly, you can get hold of a copy of Code Blue for the Rainbow.
This (along with MS-DOS 3.1 and the patches that Suitable Solutions
came up with for Code Blue to work with MS-DOS 3.1) allows a large
number of IBM programs to run on the Rainbow.

Thirdly, you can replace the Rainbow character ROM with an IBM-PC
compatible character ROM which allows many of the IBM-PC characters
to be generated on the Rainbow.  It doesn't do anything about the
24-line screen on the Rainbow though (Code Blue does have a way of
getting around this, but you still don't get a true 25-line screen).

Two classes of programs have little or no hope of running on the
Rainbow:

    1)	Graphics programs.  The Rainbow graphics board is totally
	unlike any of the IBM graphics boards, so any graphics have
	no hope of running unless they run inside an execution
	environment like Microsoft Windows.  (There is a version of
	Microsoft Windows for the Rainbow, from Leonard Berk
	Consulting in Canada - its main limitation is that it is
	monochrome only;  it is best if you run it with a Turbow
	card or else it's a bit sluggish ...).

    2)	Communications programs.  The communications controller
	for the Rainbow is not like that on most PC clones, and
	most communications programs for the IBM-PC do not use the
	ROM-BIOS communications routines because they are badly
	brain-damaged.  If you are "lucky" enough that the program
	you're running uses the BIOS, then it will work with Code
	Blue, but this includes NO commercial software.  (Exception:
	many communications programs that run under Windows and that
	use the Windows communications functions will work OK on the
	Rainbow).

Other sorts of programs may or may not work.  For example, some
versions of the Norton Utilities work OK with the combination of
MS-DOS 3.1B and Code Blue, and others don't.  Some version of the
Norton Utilities will even run on just MS-DOS 3.1B and no Code Blue 
(but not 4.5 and above).  Fastback and similar programs can't be used 
in the most efficient ways since they rely on manipulating the floppy 
disk controller (different on the Rainbow), though some of these 
sorts of programs have ways of running in a reduced mode which uses 
only DOS functions and these _should_ work.

The Rainbow isn't a bad little machine, but if you really want true
IBM compatibility you need to get a clone.  None of these products
mentioned above gives you total compatibility, though if you use all
of them then a surprising amount of IBM-PC code will work.  But you'll
never get _all_ IBM-PC code to work on the Rainbow.

Good luck -
						Bruce C. Wright