🚀 go-pugleaf

In article <4438@eagle.wesleyan.edu>, dkonerding@eagle.wesleyan.edu writes:
> 	Hello, folks.  I've got a small problem with a Rainbow.
> 	There's a 10MB HD that autoboots.  The machine came with MSDOS 2.05,
> and I've installed that on the HD. However, when I insert a MSDOS 3.3 disk,
> and try to run a program, it boots me to an error screen, or just plain 
> returns me to the prompt.  I assume that is because MSDOS 2.05 itself 
> cannot run programs that new.  However, using 2.05's sys command, I was 
> able to install 3.3 DOS on the HD-- however, the Rainbow "does not 
> recognize it".  Therefore, I cannot run (I assume) anything that does 
> not work with old DOS).

I'm not quite sure what the configuration of the Rainbow is from the
description you've given, but I can tell you a few things about the
machine that will explain the problems you're having.

First of all, the Rainbow is not PC compatible.  It does run MS-DOS, but
that's because it has a specially customized version of MS-DOS that knows
how to deal with the hardware differences.  For example, screen memory
is organized differently and in a different location, graphics are totally
different from PC graphics, the disk interface can only be described as
odd (the floppy driver actually runs on the Z80 rather than the 8088),
the serial I/O is done in a completely different way, the ROM-BIOS is
different, etc, etc.  Forget running DOS 3.3 on it - the standard DOS 
3.3 is expecting a PC compatible, and the Rainbow just isn't.  In many 
ways it's not a bad machine (especially for its time - 1983;  one of the 
nice things you can do with it is put up to 896K of memory on the machine - 
all of it useable by MS-DOS:  the limit on the IBM-PC is that the video 
memory sits smack in the middle of your address space and limits you to 
640k) but it's different from most machines you see today and it's dated.

Secondly, the floppy drives on the Rainbow are not 360K DSDD floppy
drives - they are 400K SSDD 96TPI drives.  This is an odd format that isn't
very popular any more - though the machine can read (and sometimes write,
if you are lucky) SSDD 180K floppy drives.

I am not sure why the machine is running MS-DOS 2.05.  The version that
was normally run with a hard disk drive on the Rainbow was 2.11.  It's
possible that the hard disk isn't a DEC or DEC compatible hard disk (there
were a couple made for the machine that didn't attach into the machine in
the standard way - I think Convex made one of them - and they may not
require MS-DOS 2.11).

In any event, none of this helps you get things running.  As far as I
know, there isn't an MS-DOS 3.3 for the Rainbow, but there is an MS-DOS
3.1.  It is available from the major systems house that still produces 
new Rainbow products, Suitable Solutions.  They can also sell a copy of
Code Blue, which is a software product that provides >nearly< complete
IBM-PC emulation as long as the program you're running doesn't do anything
too hardware-dependent (it DOES provide video memory emulation, which is
the major hardware dependency in most non-communications PC software).  
Also available is a floppy disk drive that can read and write standard
360K floppies, and one that will read and write 720K 3.5" floppies; extra
memory cards (the Rainbow didn't use a standard PC bus and won't take
normal PC memory, you need a special card.  I can't tell from your stated
configuration whether you have one already or not.  If you do, you can
just add standard 64K or 256K memory chips to it, though you may need to 
adjust some of the jumpers on the card to tell it what kind of chips you
are using);  Windows for the Rainbow;  and a 286 accelerator card.  Their 
address is:

		Suitable Solutions
		1700 Wyatt Drive, Suite 12
		Santa Clara, CA 95054
		408-727-9090

Their prices are somewhat above the PC-clone prices but not greatly so;
they are also extremely reputable people to deal with.

You can also often find used Rainbow equipment from places that sell used
DEC equipment such as Newman or Midwest or Brookline.  You might be able
to find them in something like Computer Shopper or ask around a local
college or other DEC shop - their catalogs are everywhere at such a place,
and their prices on used Rainbow hardware will be lower than Suitable
Solutions'.

I'm not sure I would recommend upgrading the machine to a more reasonable
configuration (memory especially seems small by modern standards) - it
depends on whether you want to live with the compatibility problems or not.
It can still be a very nice and useable machine, but even with MS-DOS 3.1
and Code Blue, you still can't just drop any random PC program onto it and
expect it to work.  

As for word processors, there are four things you could try:

    1.	It is likely that if you get Code Blue and MS-DOS 3.1 from Suitable
 	Solutions, that your favorite PC word processor will run on the 
	Rainbow if you can convert it to the appropriate disk format (you
	may or may not want to consider adding a 360 or 720K floppy drive).
	Word processors (except Microsoft Word, I don't know if it can be
	made to run on the Rainbow but it is notorious for being hardware
	dependent) tend to work pretty well in this environment.
    2.	You could probably locate a copy of SEDT from a DEC-related bulletin
	board;  this is a nice screen editor that is public domain.  Check
	a DEC-related newsgroup such as comp.sys.dec.micro, if you have
	access to usenet;  if not and you can't locate any mail me and I
	will try to locate one in your area.
    3.	EDT from Boston Business Computing, which is a pretty nice screen
	editor but which costs real money ($300).
		Boston Business Computing
		Riverwalk Center
		360 Merrimack Street
		Lawrence, MA 01843
    4.	VEDIT from CompuView, which is a screen editor with a TECO-like
	macro language.  I don't know the cost - I think they have several
	versions (VEDIT, VEDIT/PlUS) the last I knew, with a fairly steep
	price curve (like maybe $100 for VEDIT, $250 for VEDIT/PLUS).
		CompuView
		1955 Pauline Blvd
		Ann Arbor, MI 48103

One way or another, unless you can make do with nothing but SEDT,
you will either have to spend some money on the machine or sell it
and buy a PC clone.  Be forewarned however that it doesn't have a
great deal of resale value ... probably under $500;  a Rainbow with
128K of memory, monochrome monitor, no graphics board, and no hard 
drive sells for around $200-$300 and less if you sell to a reseller 
such as Newman.  I don't know how much the hard drive would add; if
it's DEC it might add a bit more, but it sounds like it's third-party,
so my guess is that the machine is worth maybe $400 retail (if you
can find someone who still uses Rainbows).

Good luck.

					Bruce C. Wright