AiG interviews Brian W. Fuesz, the creator of the Cygnus-1
For those people unfamiliar with the Cygnus-1, visit the
AiG page on the subject.
Why did you begin to develop the Cygnus-1 board?
[Brian W. Fuesz] I developed Cygnus-1 to serve as a
multi-processor, parallel computer system. As I designed the board,
I included features that would also allow it to function as a
single board computer for embedded systems applications as
How long did it take to develop?
[Brian W. Fuesz] I developed the board over a period of
about six months, although there was a nine month period during
which I developed two wire-wrapped prototype systems.
The 68000 is considered by many to be outdated. Why did
you choose this as the basis of the simulator?
[Brian W. Fuesz] I used the 68k because I preferred the
68k-series architecture and assembly language over the Intel x86
family, which is more common because of its use in PCs. I
also selected the 68k because I had several Amiga systems and
associated development software, which was useful during
development of a 68k-based system.
What factors led you to use an Amiga as the development
[Brian W. Fuesz] At the time, I did not have a PC, so I
used the Amiga. Plus, I was able to leverage off of my 68k
assemblers and C compilers for the Amiga.
What were the Amigas system specification that the
software was developed on?
[Brian W. Fuesz] I used an Amiga 1000 with 2MB RAM and two
floppy drives. I did not have a hard disk drive.
What software did you use on the Amiga?
[Brian W. Fuesz] I used Amiga assemblers and C compilers.
I also designed and built a wire-wrapped EPROM burner that utilized
the Amiga's parallel port. Code that was developed on the
Amiga was burned onto EPROMs using this device.
Did you discover any problems caused by using the Amiga
as a development system?
[Brian W. Fuesz] No, it actually worked quite well.
I wrote a loader program to take programs written on the Amiga and
transfer them to a fixed memory location in the EPROMs for
How easy was it to get developer information and
software on the Amiga?
[Brian W. Fuesz] I used commonly available Amiga
What lessons did you learn from creating the
[Brian W. Fuesz] I was able to develop a fully functioning
computer system. However, the goal of making a parallel
computer was overtaken by microprocessor technology. When I
first started on the project, a PC cost about $2000. I figured that
I could produce a Cygnus-1 board in quanities of four boards for
about $130 each (materials cost only, not including the labor to
assemble and test the boards or the non-recurring engineering
development costs). Thus, I could put together a twelve processor
Cygnus-1 system for about $1560, which would be cheaper than a PC
and would be faster, too. While this was true when I started
the project, by the time I had finished, a PC with equivalent
compute power to the twelve-processor Cygnus-1 system, cost about
$1200. So Cygnus-1 lost its price appeal. In addition,
a single processor PC was much easier to develop software for than
the multi-processor Cygnus-1 system.
The project used the 68008 and 68000. Were there ever
any plans to using a faster version of the 68k family?
[Brian W. Fuesz] I had considered using a 68020 or 68030,
but the economics at project completion made such a new development
Can you break down the total cost of producing the
[Brian W. Fuesz] As I said earlier, it costs about $130 to
build a board. I don't recall details at the component
Finally, what tips would you give for anyone wishing to
develop a similar system on the Amiga?
[Brian W. Fuesz] Well, if anyone wants to do something
similar, I would encourage them to use a Motorola 68HC11
microcontroller instead of a 68k. However, if they want the
leverage off of their Amiga software tools, then a 68k is fine. I'd
recommend the EC version of the 68k. As I recall, this processor
can be wired to use an 8-bit databus, which I would recommend -- it
requires much less board space and you really don't typically need
the gain in speed form a 16-bit databus.
Oh, and they had better be prepared to consume alot of hours in
design, development, and test. :-)
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