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- Path: sparky!uunet!destroyer!gatech!concert!ais.com!bruce
- From: bruce@ais.com (Bruce C. Wright)
- Newsgroups: comp.sys.dec.micro
- Subject: Re: Rainbow
- Message-ID: <1992Nov17.122608.5842@ais.com>
- Date: 17 Nov 92 12:26:08 GMT
- References: <1992Nov16.155538.874@infodev.cam.ac.uk>
- Organization: Applied Information Systems, Chapel Hill, NC
- Lines: 56
-
- In article <1992Nov16.155538.874@infodev.cam.ac.uk>, nec10@cus.cam.ac.uk (N.E. Cole) writes:
- > I may be given a DEC Rainbow (10 MB HD) soon, are there any patches about to
- > allow me to run DOS later than 2.11 on it and to use the enchanced graphics as
- > cga etc???
-
- There is a version of DOS 3.1 customized for the Rainbow, but my
- understanding from talking with one of the developers of the
- Rainbow adaptations is that it isn't just a `few patches'. You
- can't reasonably start with either the Rainbow DOS 2.11 version
- nor with an IBM DOS 3.1 version and get a useable system without
- a LOT of work, and that assumes that you have the _sources_ to
- the DOS [!!].
-
- Unfortunately I don't know where you can get DOS 3.1 for the
- Rainbow these days. At one time you could get it `under the
- table' from DEC, and then when DEC dropped the Rainbow they
- licensed the rights to the Rainbow adaptations for DOS 3.1 to
- Suitable Solutions, which is now out of the Rainbow business.
- It's possible that one or another of the Rainbow user's groups
- has picked it up, but I've lost track of them.
-
- As for using the enhanced graphics as CGA, forget it. It is
- possible to run many text-mode IBM-PC applications that write
- directly to the PC screen memory on the Rainbow if you have
- the `Code Blue' software product, which allocates a frame of
- memory at the same address as the IBM video memory and copies
- it back and forth; but the graphics adapters are so far apart
- that it's just not practical to write such an intercept program.
- (It's not just a question of the memory format and the CPU
- cycles; many PC graphics programs write to the CRT controller
- chip, which the Rainbow doesn't have in a compatible form, and
- the 8088 CPU doesn't have protected mode so there is no way to
- virtualize the references to the hardware).
-
- There are a few graphics programs floating around for the Rainbow,
- and there is also a version of Microsoft Windows 3.0 for the
- Rainbow (obviously Windows 3.1 isn't possible because it requires
- protected mode). It only runs in monochrome (2-color), but it
- has more resolution than the CGA adapter so it isn't quite as
- bad as running Windows on a CGA. It _is_ worthwhile to find one
- of the Rainbow 286 accelerator cards (Turbow 286 was one of them,
- sold by Suitable Solutions) if you run Windows since it takes
- just a bit of the CPU :-).
-
- Unfortunately, since the Rainbow is an orphan machine at this
- point, there's not any one place that you can go to get any of
- this stuff. You may be able to find one or another of these
- things at one of the used DEC equipment dealers, or at a swap
- meet or user group (or from someone on the net or a BBS), but
- it's going to take some digging. If you get the machine I may
- be able to pull together some Rainbow software to send you, but
- we don't have any Rainbow hardware for sale.
-
- Good luck,
-
- Bruce C. Wright
-