21 Apr
1998
21 Apr
'98
2:28 p.m.
<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
It was preceeded by at least three others. L-bus from Control Systems
of natick MA for 8008. Intel had the MCS bus and later multibus.
<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
More likely 8088 or 8086 with 1meg. The 286 s100 crates could carry at
least 16meg and 4meg would not be out of line.
<in BASIC. A lot of single board Z80, 8086, and 80286 systems (like
<Altos) built this same basic configuration, but without an expansion
<bus.
AmproLB and xerox820 were pretty well known.
<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
IT did but it was exclusively 6800/6809.
<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
It was processor specific, if you weren't using MOTO cpu it was
inappropriate.
<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
Only the very earliest LSI-11 system ised the RK05 series as they were
replaced very quickly by the RL01 and later RL02. An 11V03 was 32kb ram,
two DL serial lines and RX01 floppy in the 30" short cab. The 11T03 added
a pair of RK05 disks.
By the early to mid 80s the 11/23 cpu had replaced the slow 11/03 cpu and
memory was typically 128-256k.
<written in FORTRAN, DIBOL, or BASIC, usually running on the RT-11
RSTS and RSX-11 timesharing and multitasking OSs were available as well
as Ultrix-11(dec unix) by the mid 80s.
<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
DEC owned the license there were at least three that were licensed for
it, Heath/schulmber/zenith, plessy and one of the military aircraft guys.
DEC also sold raw chips, the T-11 and J-11 being notable.
Most of the volume production of chips was by AMD and Harris to DEC spec.
Also CTbus (pro350/380), UNIBUS 11/24, 11/74, 11/84 are two more examples
of DEC PDP-11 buses used for micros.
<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
Omnibus was the real PDP-8(E,F,M,A series) and intersil had a bus that
was also used by harris. The 6120 was supplanted by the faster 6120
that had the EMA integrated into it. The DECMATE-II/III used the 6120.
Harris was the second source. However they out produced intersil on the
raw parts.
DECs first 32bit micro that was complete on one chip was the 78032 (aka
microvax-II). It is still a popular cpu for those that like a good
performing system that runs as DEC would advertize 24x7x365. The ones I
have did and still do exactly that save for power failures.
<had a bus for the NOVA minis and I believe Fairchild made a micro
<version based on the 9440 microprocessor (NOVA instruction set). Texas
Microflame. It was supposed to be a faster version of the micronova. I
have specs in my collection.
TI had no less than many different busses depending on model and the group
that originated the system.
Allison