THE DIGITAL GROUP
The Digital Group |
One
of the most original manufacturers of microcomputer equipment was the
digital group of Denver (never to be confused with Digital Equipment
Corp!) This group of hobbyists and designers, led by Dr. Robert Suding,
could be considered more of a cult than a company because they adhered
to a set of beliefs regarding computers and microprocessors that was
generally at odds with the rest of the industry. The Digital
Group (or, as they preferred, "the digital group") believed
that the industry would constantly develop new microprocessors and
that the computer hobbyist should have a personal computer system that
allowed him to change from one processor to another without losing the
investment in the total system. They realized that the major part of
the investment in computer equipment was spent on memory, interfaces,
software, and peripherals. Therefore, they reasoned that if you
purchase a CPU that quickly becomes obsolete (as they all do,) any
investment in memory and peripherals specifically designed only for
that CPU will be made totally obsolete. The digital group systems were
designed to be independent of the manufacturer's chip design. Complete
system compatibility was maintained at the CPU card level. All memory,
I/O, and peripherals were completely independent of the CPU selected.
They provided architectures from four CPU manufacturers: Zilog/ Mostek
Z-80, Inter 8080, Motorola 6800, and MOS Technology 6502. With the
digital group system, you could change from
a Z-80 to a 6800 by literally un-plugging the Z-80 board and
plugging in a 6800 board. Once you had done so, all you had to do was
power-up and read-in the 6800 operating system from a cassette, and
you had a 6800 system. The same was true of the 6502 board. This was
the basic idea behind the digital group designs, and it was very
attractive, mainly to hobbyists. In addition
to the interchangeability of processors, the digital group system had
quite a few other features that were far in advance of the other early
microcomputers. It did not require a front panel with switches and
lights since all the start-up software was contained in a ROM. It used
a combination video and cassette interface board at a time when other
computers still relied upon teletypes and provided a cassette-based
operating system, which could use a standard unmodified cassette
recorder to operate at 110 characters per second where other systems
operated at 30 characters per second. It had a crystal-controlled
interface that did not require constant adjustment and was extremely
reliable. The video portion displayed 16 lines by 32 characters of a 7
by 9 character matrix and included math symbols, special symbols, and
even the Greek alphabet. The Digital
Group system used reliable 8K static memory boards that would work
with any of the CPU boards selected. In addition,
the Digital Group system was available to users as either a four-board
system or any other sized system according to the owner's
requirements. Since the system was designed for hobbyists, the highest
level of interchangeability was provided. Given all
these advantages, the reader may wonder why the digital group was not
more successful as a computer manufacturer. Well, they were completely
hobbyist-oriented, and while they had dealers they never supplied
equipment on a steady basis. You really had to want a Digital Group
system very badly to put up with their erratic shipping habits. They
only promised to ship orders in sequence received, and dealers had to
wait in line with retail customers. When a
customer came into my store and asked for a Digital Group system, I
would carefully explain the terms. The customer must completely pay
for the system up front. I could not give a delivery date, and most
likely the board kits would arrive in haphazard fashion with no order
to the supply. It was almost impossible to get an assembled unit, so
the customer must have the ability to solder complex printed-circuit
boards. In addition, when the computer was completed it would still
require complicated tests and adjustments requiring electronic test
equipment. I did not have this equipment, but if the customer wanted I
would send his assembled computer to my friends at the Personal
Computer Company in Frazer, Pennsylvania, who specialized in Digital
Group computers. They assembled these and installed them into a very
attractive wooden cabinet which they called a "Personal
Computer." As far as I know, they were the first to use this term
for a microcomputer, way back in 1975 (not Apple as they often claim.)
The reason for the wooden cabinet was partially that digital group did
not sell any cabinets for a long time. When they finally designed some
very attractive cabinets for their equipment, it was almost impossible
get one delivered. With all
these negative situations, you may wonder why I bothered to become a
dealer for this computer cult? (It could hardly be called a company.)
Well, it was my principle that Computer Mart of New York would sell
all available microcomputers. I also hoped that they would become more
business-like. Besides, I did manage to sell most people who asked for
digital group on something that would make them happier. The demise
of digital group happened quite a bit before the general disappearance
of all 8-bit S-100 companies. There were just not many hobbyists who
subscribed to the ideas of the group, and when the pool was used up
the company expired. Even dealers who had based their whole business
on the system finally had to give up because non-scheduled deliveries
drove them out of business. As you might
imagine, anyone who finally succeeded in building and operating a
digital group machine became one of an exclusive brotherhood who were
one of the loyal group of users. Long after the demise of the company,
the user groups carried on, and there were even third-party small
manufacturers who made compatible equipment such as communication
boards, floppy disk systems, and speech boards. One of these was Aeon
Electronics, also of Denver Company, who made equipment well into
1983. Finally, even the user groups gave up, and the entire concept
died.
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