rzh@LLL-LCC.LLNL.GOV (Roger Hanscom) (05/25/90)
Sorry to post this, but e-mail to ficc.ferranti.com failed. Peter da Silva writes: >I have a Xerox 820 with 2 SS/DD drives. Can I just get a couble of cheepy >IBM-PC 360K drives and stick them in there to get DS/DD, or is there some Unfortunately, Peter, the 820 is based on the WD 1771 controller which is SD *only*. There are (were?) upgrade kits available for this beast to make it DS/DD (390K on 5.25" diskettes). When applied to the 820, it thinks it's a Kaypro. I did one, and jumped the clock to 5 MHz. The result is a really nice machine! The vendor had connections to MicroC, and was located in Aloha, Oregon. I can get more info, if you're in- terested. It also may be possible to put two DS drives on the vanilla 820, and use sides as logical drives, i.e. A: is drive 1 side 1, B: is drive 1 side2, C: is drive 2 side1, etc. This works best with 8" drives, but I think that you'll have only about 250K per side because each side is formatted as standard SS/SD (26 128b sectors/track, 77 tracks). roger rzh@lll-lcc.llnl.gov Q: Know the difference between a terrorist and a woman with PMS? A: One can negotiate with the terrorist!
Sprague.WBST311@XEROX.COM (05/29/90)
> I have a Xerox 820 with 2 SS/DD drives.
By the looks of it, Peter has an 820-II, not an 820. I have some comments
on Rogers message though.
While it's true that the Xerox 820 can ONLY handle single density, it can
indeed handle double sided drives, 5 1/4 or 8 inch. And yes, you can use
"cheepy IBM-PC 360K" drives on them ... you will just end up with DS/SD
drives.
As to the 820-II, I had a pair of "cheepy IBM-PC 360K" drives on mine. Let
me point out that you will want to use CONFIGUR, to change the step rate to
6 mS.
There is one thing to watch out for however, when converting a Xerox 829-II
(and 820 no doubt). That is the drive cable. Many of the single sided
disk cables are missing the wires carrying the signals needed for the
double sided drives. I no longer remember which ones, but if I remember
right, four wires are missing (two are grounds).
~ Mike
Sprague.Wbst311@Xerox.Competer@ficc.ferranti.com (Peter da Silva) (05/30/90)
In article <9005251653.AA11312@lll-lcc.llnl.gov> rzh@LLL-LCC.LLNL.GOV (Roger Hanscom) writes: > Unfortunately, Peter, the 820 is based on the WD 1771 controller which is > SD *only*. Funny. I'm already running DD/SS. This is an 820-II. -- `-_-' Peter da Silva. +1 713 274 5180. <peter@ficc.ferranti.com> 'U` Have you hugged your wolf today? <peter@sugar.hackercorp.com> @FIN Dirty words: Zhghnyyl erphefvir vayvar shapgvbaf.