Talk:Rainbow 100

Keyboard?
While it's indisputable that the LK201 keyboard layout influenced the standard extended keyboard available on most modern desktop computers, the IBM PC's mechanical keyboard with buckling spreings was far superior, quality and feel-wise, to the membrane-based LK201.

VT52?
Not only does the Rainbow emulate the VT220, but also the VT52, if I remember correctly. On startup, youd be presented with a menu to boot from drives A, B, C, D, or E, or go to the terminal mode, or to the self-diagnostic test. Using F3 to enter SETUP you could change the congiguration of the emulated terminal, plus some other things like keyclick, baud rate of the serial port etc etc.

Thô MS-DOS on the IBM PCs only adressed 640K of memory even if more was available, the same DOS on the Rainbow (or was it an adapted version, not sure. I use 2.11 I think) could adress up to the 896K if it was all available.

Unpacking problem?
ISTR reading that another annoyance about the Rainbow was that it was delivered in a six foot cube box essentially inside another six foot cube box; the outer box had to be lifted clear to get to the computer - it thus meant that it had to be unpacked in a room with at least a 12 feet high ceiling. Can anyone confirm that?

Apepper 21:56, 12 April 2007 (UTC)




 * You are probably thinking of another DEC computer like the PDP or VAX, not the Rainbow. --(unsigned comment) 2014-05-08T16:39:40‎ OMPIRE

Photo
Is this it? -- AnonMoos (talk) 15:45, 29 October 2008 (UTC)


 * Yes, it is the Rainbow. Rilak (talk) 04:55, 30 October 2008 (UTC)

Ghostbusters
Interestingly, this is the machine seen in the 1984 film Ghostbusters. . Don't know if it warrants a mention or not though. ;) 66.191.19.217 (talk)

There is also a scene in the movie The Philadelphia Experiment where an advertisement for the Rainbow is playing on a TV in the background. —Preceding unsigned comment added by 124.170.146.228 (talk) 22:23, 3 January 2009 (UTC)

Some references
from http://www.old-computers.com/MUSEUM/computer.asp?st=1&c=284 Full-stroke keyboard with function keys, editing keypad and numeric keypad. Intel 8088 + Zilog Z80 A 4.81 MHz (8088) / 4 MHz (Z80) RAM:64 KB (up to 896 KB) ROM:24 KB (includes self-diagnostics) TEXT MODES:40 x 24 / 80 x 24 / 132 x 24 GRAPHIC MODES:320 x 200 / 640 x 200 / 800 x 240 COLORS:16 among 4096 (optional) SIZE / WEIGHT:48.3 (W) x 36.3 (D) x 16.5 (H) cm (system unit) I/O PORTS:2 x RS-232, keyboard, monitor Two 400 KB 5.25'' disk-drives MS DOS(different than IBM MS DOS) + CP/M (+ CP/M 86 - Prologue ) Built-in switching power supply unit 3 expansion slots

I remember the interior of these had a bronze colored internal frame- I'm not sure it it was really bronze, Also, the monitor port was not CGA or VGA, it might have been a proprietary DEC port. Possibly standard for VT Terminals? Cuvtixo (talk) 20:25, 11 April 2009 (UTC)

Microfilm Application
At 3M in the mid-1980s we sold a family of four microfilm aperture card duplicator machines, the 9x8 series. The DEC Rainbow 100 was available as an extra-cost option. It was called a 'system controller' to avoid a USAF embargo on personal computer purchases. Its purpose was ostensibly to facilitate operation of the 9x8. In actuality, it greatly inhibited jam recovery, which was the result of poor system integration on the part of 3M. Most users unplugged the DEC, and relegated it to spider habitat service.LorenzoB (talk) 20:42, 7 September 2013 (UTC)

FDDs : I do not think, that both share one single spindle
If

''Of note was the single motor used to drive both disk drives via a common spindle, which were arranged one on top of the other. That meant that one disk went underneath the first but inserted upside-down. This earned the diskette drive the nickname "toaster".[citation needed] The unusual orientation''

is true (one motor, one spindle, one of two discs upside-down) then

1. always two drives run, if only one disc is to be read. If a second disc is inserted, would mean that often unnecessarily the 2nd disc rotates and weares out.

2. the two dics are driven in opposite directions (according to their geometry). I do not think, that the motor (and the sole spindle) turns sometimes in one and at ozher times in the other direction.

--

The Operating Manual

http://bitsavers.trailing-edge.com/pdf/dec/pdp11/microPDP11/AZ-FI13A-MC_MicroPDP11_Systems_Owners_Manual_Jun86.pdf

speaks on page 2-9

of RX50 Diskettes

and shows a double drive, that seems (see the levers) to take the second diskette upside-down.

At least for copying diskettes, one to the other it is necessary, that both diskettes are inserted, are driven in the same direction responding to the case (soft, flat sleeve) and are driven (at least for some time intervalls) at the same time.

I expect, that contradicts to the existence of a single spindle for both drives.

--Helium4 (talk) 13:36, 23 August 2018 (UTC)

The RX-50 has one spindle for two disks. The top disk is right side up, the bottom one is up side down (that's the trick that makes this work). There's one motor, one spindle, and both the disks spin when accessed. I have a half dozen of these actual drives in my basement and have used them on my Rainbow since 1983. Wear has never really been an issue on the RX-50 diskettes.

http://bitsavers.org/pdf/dec/rainbow/ms-dos/AA-DY51A-XV_Rainbow_MS-DOS_Version_2.11_Documentation_Oct84.pdf pages 50-51 show the A disk right side up and pages 65-66 show inserting the B disk upside down if you are looking for a reference to the docs that came with MS-DOS 2.11 for the DEC Rainbow 100 (A or B, it didn't matter).

--Bsdimp (talk) 23:01, 19 August 2021 (UTC)

Software
I don't have a reference for this, but Borland Turbo Pascal was released for the Rainbow and was a pretty decent development environment and allowed access to the screen's graphics mode. I used it for a class project though I can't recall if it ran under CPM/86 or MS-DOS. — Preceding unsigned comment added by 108.202.33.17 (talk) 05:17, 26 February 2019 (UTC)