[net.micro] different versions of the DEC Rainbow.

jss@sjuvax.UUCP (Jonathan Shapiro) (10/24/84)

[Aren't you hungry..?]

The rainbow 100b is the b revision of the motherboard.  The original rainbow,
now obsolete, could only be expanded up to something like 256K.  The b revision
can be expanded up to the full 896 that you are allowed to put on such a beast, and most of that is on the motherboard.

tony@ur-cvsvax.UUCP (Tony Movshon) (11/05/84)

> [Aren't you hungry..?]
> 
> The rainbow 100b is the b revision of the motherboard.  The original rainbow,
> now obsolete, could only be expanded up to something like 256K.  The b
> revision can be expanded up to the full 896k that you are allowed to put on
> such a beast, and most of that is on the motherboard.

To be a little more specific:

	The DEC Rainbow 100 (aka the 100A) is the first release Rainbow.
	It comes with dual floppies and 64 kbytes expandable to 256k in
	the original version. DEC now uffers an upgrade kit that permits
	expansion to 832k. Hard disk support can be added, as well as
	graphics; extended communications can be added if you don't want
	a hard disk.

	The Rainbow 100+ is a hard disk plus dual floppy system, with 128k
	expandable to 896k. It uses the "B" motherboard.

	The Rainbow 100B is a 100+ without the hard disk (maybe it should
	be called a 100-).

	All Rainbows can take a graphics option and memory expansion; the
	100+/100B takes slightly greater advantage of the graphics board,
	but the difference is trivial.

	BOTTOM LINE: if you want a Rainbow, the 100A might be had rather
	cheaply (DEC now makes the 100B and 100+ only). BUT you can now
	expand the 100A to 832kbytes, so there is no practical memory
	limitation. By the way, DEC has been selling 5mbyte hard-disk and
	controller kits for $1495 list (about $1100 from some vendors), so
	a hard-disk 100A can be assembled reasonably economically.