Date   : Wed, 30 Sep 1992 10:27:41 -0400
From   : Jay Sage <sage@ll.mit.edu>
Subject: Re: Ferguson Big Board = Xerox 820

Martin Halford wrote:

>> I've been told that the Xerox 820 cpm machine with SSSD 8" drives, is
>> just a Ferguson Big Board "in disguise". Is this true?? What's a Ferguson
>> Big Board???

   It is basically true.  Jim Ferguson developed a very nice single-board
Z80 computer kit at a very attractive price.  That was my first computer,
and it was very nicely done.

   Two other computers used the basic Ferguson design: Xerox and Kaypro.  As
I understand it, Xerox did the right thing legally and ethically; they paid
Ferguson to design a similar board to serve as the basis for their personal
computer.  But they did the wrong thing technically.  They insisted on some
changes from the BigBoard design; all, as far as I could tell (I also had a
Xerox 820 for a while), made the computer worse!

   Kaypro, on the other hand, apparently stole the BigBoard concept. 
However, they did the right thing technically, introducing some nice
improvements (such as support for 5" drives).  This was the very first
Kaypro computer.  In Kaypro's defense, I have been told that they did later
reach an agreement with Ferguson and did pay him.  Unfortunately, Kaypro
went downhill from there and developed a knack for coming out with new
designs that were worse than their predecessors.  I have a Kaypro 286/16 AT
clone.  It is the only clone on which I have had trouble with standard
software.  Kaypro's recent bankruptcy was well-earned.  The old CP/M
machines were probably the best CP/M computers ever made in terms of
reliability, and many are still in regular use.

>> My hidden agenda is that someone is willing to sell me software for my
>> Xerox 820 which runs on his Ferguson Big Board machine. The claim is that
>> the two machines are identical.

   The machines are very nearly identical.  This goes back quite a few
years, but my recollection is that I could almost always move software
between the BigBoard and the 820 without having to make any changes.  Of
course, you should understand that most software can moved between any CP/M
computers.  The only changes that are required are configuration for
different terminal codes and different port addresses for I/O.

   The Ferguson boards (including, I believe, the 820 and early Kaypros)
used memory-mapped video with BIOS support for terminal emulation.  Some
BigBoard software actually wrote directly to video RAM for better
performance.  As I recall, such software on my BigBoard would run on the
820.

   In short, I think that the BigBoard software will work, but you should
ask for the right to return it if it cannot be made to work.

-- Jay Sage