20220606

DEC Rainbow Floppies Found on EBAY

 DEC Rainbow Floppies on EBAY

A group called "Australia SDC" recently liquidated their DEC Rainbow floppy collection on EBAY. I won the auction and will be placing them up once I have them imaged. There were a lot of application floppies that I'll do a separate blog post about (about half of the lot are programs like tk-solver, 20/20, MT Pascal, CBASIC, etc)

However, interestingly they had the following floppies that contain drivers for 3rd party software:
  • DM220 Disk Utilities -- Drivers for Duncan Mac Donald products (Version 1.0 4/14/1986 MS/DOS)
  • DEC RAINBOW MS-DOS 2.05 for ACT WINCHESTER (believed to be a boot disk with the ACT Winchester driver included, ala the Univation disk controllers that did a similar trick)
  • DEC RAINBOW 100 CP/M-86 for the ACT Winchester v28.09.84
  • C.H.S. Corp XDRV.SYS Version 1.0 Rainbow MS-DOS format (this is for CHS's dual hard disk controller)
  • Rainbow Diag Disk (8087 co-processor and extended memory BL-DE29A-BV
  • O.P. SYSTEM For Rainbow Winchester Utility/Diag Disk BL-W968B-M3
  • Winchester Utility/Diag Disk DOS 2.11 (BL-w968B-M3)
  • ZV0003.M3 V2.0 util/diag disk (hand written: R-Bow Hard disk Util) BL-W968B-M3
  • Winchester Utility/Diag disk BL-W968B-M3
The last 4 appear to be the same disk, but they have radically different labels, so it's unclear what else might be on the disks.

There's about 20 unlabeled RX-50s in the cache as well. One of them says 'backup 1986' on it, but no clue if that's a complete backup, or just someone's hack to xfer something. I'll do a blog on that as well.

The Duncan Mac Donald products diskette is interesting, since I've since ads for his products for the Rainbow, but no actual drivers. The ACT Winchester is interesting. I'll have to look at that in detail as well. I have another copy of the CHS diskette, and the driver is included on SS MS-DOS 3.10b disks that I have, but you never know what else might be there.

all in all, an interesting find.

20220331

DEC Rainbow Power Supply Specs

 DEC Rainbow 100B Power Supply Specs


For the next time I'm looking for this... The DEC Rainbow power supply, as documented in the TM100 technical reference manual, is:

Output: +5.1V +/- 6% 2.5-11.5A, +12.1V +/- 6% 0.6-6.7A, -12V +/- 7% 0.0-0.15A
Input: 115V 6A (218W)

Pinout:

Pin Function
1 ACOK H
2 DCBIAS (unused)
3 Key
4 -12V Input
5,6 +12V Input
7,8,9 +5V Input
10,11,12,13 Ground (DC Return)

Most ATX power supplies supply more 5V and less 12V than is needed for the Rainbow to power the system. However, the 12V supplies are in large part for the older disk technology in the Rainbow and if you are using emulators you can get by with a little less, though how much less is TBD.