Old standards

From: Jack Peacock <peacock_at_simconv.com>
Date: Tue Apr 21 17:30:14 1998

From: Max Eskin [mailto:maxeskin_at_hotmail.com]

<< I'm curious about the various home/small business computer standards.
I know about the PC standard *sigh*. There was also the MSX standard
which involved a Z80 and 64K ram, I think. What other ones were there?
>>

Quite a few. from memory....the S-100, probably the earliest micro bus
to become popular. A standard business configuration for 8-bit would be
a Z-80, 64K RAM, 5.25" floppies, serial ports to a CRT terminal and
printer, and CP/M-80, running applications written in CBASIC. For
16-bit systems it would be an 80286, 1MB RAM, hard drive in the 40MB
range, 4 to 16 serial ports to CRT terminals and printers, maybe even a
modem, running MP/M or Concurrent DOS, again with applications written
in BASIC. A lot of single board Z80, 8086, and 80286 systems (like
Altos) built this same basic configuration, but without an expansion
bus.

The SS-50, a competitor for the S-100 but using Motorola 6800 CPU, never
really caught on. VME, an industrial bus still alive today, lots of
different CPUs supported over the years, but it started with an Intel
8080. Motorola came up with a competing bus that looked very similar to
S-100 except it used 86 pin bus, called Exor, something like that, never
caught on either, though Motorola did their best to promote it for a
while.

There were some holdovers from the mini makers. Q-bus, DEC's bus for
the PDP-11 micros and later the MicroVAX. A typical PDP would be a
PDP-11/03 CPU, 64K RAM, 2.5MB hard drive (RK05), 4 port serial to a
VT-100 terminal, and a DECwriter II for a printer. Business apps were
written in FORTRAN, DIBOL, or BASIC, usually running on the RT-11
operating system. BTW the Q-bus wasn't strictly DEC proprietary, DEC
sold PDP-11 CPU chips for a while, Plessey made their own PDP-11 systems
with them. DEC later dropped CPU sales when they found out the other
manufacturers were just taking away DEC customers, not expanding into
new markets. Sort of like MAC clones... <s>

VAX Q-bus configurations are still around in sizeable numbers (we have
some in the office). The machines aren't fast, but very reliable (as in
years per hardware failure). It's not unheard of for VMS systems to run
for a year or more between boots. A common setup in the late 80's was
the MicroVAX II (roughly equivalent to a 386), a 32-bit CPU with up to
16MB of RAM. An 8 slot chassis, holding the CPU board, 2 memory boards,
disk controller (RQDX3, MFM), tape controller (TK50), Ethernet
controller, and an 8-port serial card (DHV11). Drives would be either
70MB or 160MB. The tape drive could hold about 95MB. It ran VMS (still
in use today), or less commonly Ultrix (DEC Unix). Several languages
are available, including C, FORTRAN, COBOL, and BASIC. DEC has
discontinued new VAX Q-bus machines, and new VAXes in general, but they
have large stocks of VAX CPU chips, enough to last a few more years.

Intersil made the IM6100, a microprocessor version of the 12-bit PDP-8,
but I don't recall if a bus was ever associated with it. Data General
had a bus for the NOVA minis and I believe Fairchild made a micro
version based on the 9440 microprocessor (NOVA instruction set). Texas
Instruments made the 9900, a micro version of their minis, and it had
some kind of proprietary TI bus.
        Jack Peacock
Received on Tue Apr 21 1998 - 17:30:14 BST