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History of Jolt Serial One, Bill Ragsdale
I bought the first Jolt microcomputer out the door. I saw its
advertisement (in Byte?) and was just starting a project in security
access control. We were doing a crash project to demonstrate reading
magnetic striped ID badges for Honeywell. We needed to accept a real-time
bit sequence, extract numeric data and do a simple name vs. number lookup.
An ideal job for a small processor. But remember, this was 1976.
Development systems cost $5,000+ and none were offered for the 6502.
(Later, MOS Technology offered one and Rockwell had a very good one.)
I ordered a Jolt system on a Wednesday or Thursday and was told
Microcomputer Associates Inc. (Manny Lemas and Ray Holt) was
awaiting the first silicon of their DeMon monitor to come by air from MOS
Technology in two days, on Saturday. DeMon was a one chip Debug-Monitor
containing 1K of
ROM, 512 bytes of RAM, paralled IO, an ASCII serial interface and a
monitor program. With the 6502 processor and a simple clock you could have
a two-chip microcomputer. DeMon was later renamed Tim, Terminal Input
Monitor.
MAI received their first DeMon chips about 9 AM Saturday morning, plugged
in one, it ran, and I picked up the first unit at noon at their office.
IIRC the Jolt had an inked-in serial number 0 or 1. Over the week-end I
built a teletype interface as Jolt had a voltage output while the Teletype
had current loop.
Either at that time or shortly later MAI expanded the line to a RAM card
and an EPROM card using 2702 PROMS. The boards were about 4"x6,"
arranged in a vertical stack jointed by a ribbon cable. Only 5 volt power
was needed.
Our original programs were hand assembled and entered in hex via the
Teletype keyboard. After debug they would be punched out as paper tape,
again on the Teletype. Next came the need for an assembler. MAI had
contracted for an assembler from a local programmer. The design and
technique was very elegant: one pass from paper tape with listing, forward
references resolved and a sorted symbol table, all in 2k bytes of PROM.
The Teletype read the source code a line at a time. The text was converted
into
object code in RAM with a listing printed. Forward branches showed as
zeros in the listing but were resolved and a sorted symbol table printed
at the end. We had to write in the forward branches on the listing by hand
from the symbol table.
The programmer delivered the assembler three times, each time buggy and
incomplete. MAI got me PROMS of each version. Bob Seltzer and I would try
the release and submit bug reports. Along the way the programmer reported
he was way over budget and time and was ending the project. Bob and I
eventually manually disassembled the assembler, fixed the bugs, punched a
paper tape and used the buggy assembler, with workarounds, to assemble a
clean assembler, then burned PROMS. I then wrote a line editor and donated
it back to MAI.
In the course of software development I wrote my version of Forth
on the Jolt using the assembler and paper tape input. Next I linked up a
dual eight-inch PerSci floppy drive. With some jiggling I got the serial
port to talk to an early CRT terminal (ADM-3) at 2400 Baud. Next
came a high-speed
paper tape reader and PROM burner. All this went into a large blue box.
This became the development system at my company, Dorado Systems.
The Forth went on to be distributed as fig-FORTH by the Forth Interest
Group. I was the first president of that group from 1979 until about
1984. My 6502
Forth was transported to the Apple ][ forming the basis for its first word
processor, EasyWriter, written by John Draper.
Jolt was the first 6502 one board computer but soon was followed by
the MOS Technology's Kim
and the later Rockwell
board. Manny Lemas and Ray Holt went on to merge MAI into Synertec and did
the VIM/SYM
one board computers. Dorado Systems used the SYM as the basis for 650
energy control systems for the Lucky food stores in the mid 1980s. Our
6502 products went mostly to Honeywell for door access control products
used world-wide. Over time we migrated our development onto PCs but the
blue box, Jolt based development system was our backup for development and
PROM burning.
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