Xerox 820 documentation.

[Scott Stevens]

On Wed, 16 Mar 2005 15:03:38 -0800 (PST)
"Dwight K. Elvey" <dwight.elvey at amd.com> wrote:

> >From: "Giuseppe Sarno" <gsarno at nortel.com>
> >
> >Hi I own an Old Xerox 820 machine,
> >Can anyone help to find documentation for it ?
> >Also is there a way to download programs onto it using the
> >serial/parallel port ?
> >
> >I have seen some info at
> >http://www.classiccmp.org/pipermail/cctech/2002-September/002642.html
> ><http://www.classiccmp.org/pipermail/cctech/2002-September/002642.ht
> >ml>  but I couldn't find more.
> >
> >Thanks.
> >
> 
> Hi
>  You didn't mention if you have a disk that boots and
> has PIP under CP/M on it. If you do, you can transfer
> information as ASCII like a BASIC source program or even
> transfer .COM files by first converting them to .HEX
> files and then using DDT on the 820 to move them
> to .COM files.
>  If you are attempting to bootstrap with no disk, you'll
> have to check with others. One may be able to do it
> if it has a built in debug monitor.
>  Of course, on can always write some of ones own code
> and replace one of the internal EPROMs. It is not
> as impossible as it sounds. You just have to explore
> a little.
> Dwight
> 
> 

I used to have a Xerox 820 ages ago, and presently have a BigBoard that
I've yet never powered up.  It should have a monitor ROM on it and will
power up to a monitor prompt that you can boot CP/M from. 
Alternatively, you can run monitor commands and (I think) punch in your
own code from the keyboard.  I have (I think, somewhere, haven't seen
them in quite awhile) a full set of prints and docs for my BigBoard.  It
was originally used as a 'controller' in an industrial setting, so when
I got it, it didn't have the original monitor ROM in it, but I acquired
an image and burned one.  But like I said, I've never powered mine up.

Someday it needs to have a drive, monitor, keyboard, etc. attached.  I
believe, but again it's been years, that you can bring it up using a
keyboard and the onboard video controller, or from a console (serial
terminal) attached to one of the COM ports.

I'd be very happy for anybody who knows more about these systems to
correct me on any of the above.  I haven't run a Xerox 820 since about
1987.

-Scott