Xerox 820 lives!

From: Don Maslin <donm_at_cts.com>
Date: Mon Sep 23 19:18:01 2002

On Mon, 23 Sep 2002, Glen Goodwin wrote:

> Greetings to all --
>
> About a year ago, Joe Rigdon very kindly gave me a number of old machines
> (thanks, Joe!), among them a Xerox 820. At the time he gave it to me, the
> unit didn't power up, but today I finally found the time to give it a
> second look. After I reconnected a loose lead inside the box it came to
> life! This is my only machine with 8" disk drives, so I'm interested in
> finding a good use for it.
>
> I could use some help from the list members, though. I found *no*
> technical data via Google, and have *no* real docs for this beast. After
> poking at the 820 for a bit, here's where I'm at:

First off, Glen, is it an 820 or an 820-II? Since you have been in to
it, you should recall whether there is a daughter card that plugs in
vertically in the right rear quadrant of the motherboard. If it is
there, you have an 820-II. If not, it is an 820 and only capable of
read/write SSSD disks, and the drives are likely Shugart SA-800s. The
820-II is DSDD capable and likely has SA-850s.

> --> The "B" drive is faulty. Disk initialization fails, and it will not
> consistently read disks created on the "A" drive. Any pointers on
> replacement drives? Even if a thorough cleaning revives this drive, I'd
> like to obtain a spare.

Make sure that the heads are clean and that the guide rails for the head
assembly are clean and VERY LIGHTLY lubricated.

> --> Assuming I can't revive the "B" drive or find a replacement, how can I
> duplicate diskettes? The CP/M utilities all seem to want two drives in
> order to do their job.

There is a program named MFT45.COM (also MFT48.COM) that is capable of
single drive copy. It is a little tedious because of disk jockeying,
but it does do the job. MFT stands for Multiple File Transfer.

> --> Two of the boot diskettes which I have boot up a pretty normal looking
> version of CP/M 2.2, with a normal "A>" prompt, but another diskette
> displays the following upon boot:
>
> "Good Day! ZCPR 2.04 SYSTEM READY"
>
> and the prompt is "A0>" (obviously user group 0). What is this "ZCPR"?

Joe covered this pretty well.

> --> Some of the utilities on the boot diskettes (FMT, for example) refer to
> hard disk drives. What's involved in attaching a hard drive to this
> system?

If an 820, it is not a particularly reasonable thing to try. If an
820-II, easy if you can find the Xerox add ons. Rather more difficult
otherwise.

> --> The flimsy "User Manual" which I have states that the RS232 port may be
> configured to attach to a terminal or to a modem. How?

Probably switching the port from DTE to DCE pinout.

> --> Lastly, does anyone have any documentation on this thing? If you can
> part with it, I'd be glad to pay a fair price.

Cannot help there.
                                                - don

> Thanks in advance for any help you can provide. Although this system
> doesn't appear to be special or unique, it does seem to be a sort of nice,
> friendly critter, and I'd like to put it into use.
>
> Later --
>
> Glen
> 0/0
>
> If I am not for myself, then who will be for me?
> And if not now, when?
> -- Pirkei Avot
>
>
Received on Mon Sep 23 2002 - 19:18:01 BST