MUSEUM HISTORY
The history of C/PMuseum is actually quite short. The bug to start collecting
actually bit in the summer of 2005, when the aqcuisition of an IMSAI 8080 with some
history resulted in the first "exhibit" in the collection. Since then I have
continued to expand the collection with other systems of personal interest to me,
motivated primarily by my previous history with those systems. Many of the
systems were in non-working condition when purchased, several have already been
restored
to working order, and many still need restoration.
My goal is to eventually have every system in this collection operational, and running
examples of all the languages I have programmed those systems in. (Which unless
I cheat and start buying fully working systems is a task that could easily keep
me occupied well into my retirement - which is the also the goal!)
And yes, I am aware of the similarity between the logo, C/PM, and the well known
operating system
CP/M, it is an
deliberate pun with no misrepresentation of the operating system intended. :-)
PERSONAL HISTORY (A.K.A. the boring stuff)
My first introduction to “electronics” was in 1972, when a fourth grade teacher
who changed my life forever allowed me to play with an “introduction to electricity”
kit we had in the classroom. From the very first time I hooked up a battery and
a light bulb with two wires and it lit, I knew what I wanted to “play with” for
the rest of my life. (And for the most part, I have.) Thanks to a few textbooks brought home from a
local school by my father, who was a teacher, and some Radio Shack all-in-one kits,
by sixth grade I was already quite proficient building little (very simple) circuits,
and had a basic understanding of most of the simple components like resistors, capacitors,
and transistors. By that time I was already a “regular” at the local Radio Shack
(where the nighttime store rep happened to also be a teacher my father knew) and although
I never cold afford much, I would spend hours looking at components on the racks,
especially IC’s (which I did not yet understand) and dreaming of projects I would
someday build.
Of course, there were no “computers” at Radio Shack in those days,
although that may be
hard for some younger folks
to imagine.
In fifth grade (73-74) our classroom was one of only a few in the school district
at that time to have a “computer”, not really a computer at all but actually a connection to the local
Vo-Tech school
mainframe timeshare via a Teletype model
ASR-33 and a 110 baud dial-up modem.
(I think it was there because the classroom had previously been used as an administrative office,
not because any computer was taught to pre-high school students back then.)
So we never used it
in class, but there were a few of us especially curious types who were allowed once
to see it used to enter and run some very simple BASIC programs by a visiting teacher. When my father
had taught summer school and I tagged along for a few years I had seen him use one
of these in the school administrative offices, and actually typed a few characters
on it, but had no concept of "programming".
That summer my father had something
really new and exciting in his office – a Hazeltine 1500 green screen display terminal
and a brand new shiny 300 baud dial up modem. Well, I was in heaven. During that
summer I taught myself BASIC programming on that terminal, and with the help of
books from the local public library wrote my very first (mostly copied right from
the book) programs, which I was allowed to punch out on green paper tape on the
Teletype and I kept in a shoebox for many years.
By the time I started Junior High
in fall 1975, my father had transferred from teaching to an administrative position,
and ended up at the very same Vo-Tech where the local mainframe I learned to program
on resided. So, not only was I able to get after school access to the Junior High
“computer room” (which had two
TTY-33’s in it), he was able to introduce me directly
to a few of the (relatively young) staff in the actual IT department at the Vo-Tech.
(Several of which are still there 30 years later, one runs the department now!) At the
Vo-Tech I was able to occasionally get access to a terminal directly in the Data
Processing classroom, which had Hazeltines with an unbelievably fast direct connection
(no modem required) 1200 baud! However, there were only a few of those terminals,
and they were heavily used both in the day and by night classes, so most of the
time I had to use one of the terminals in the auxiliary classroom down the hall,
which believe it or not dialed up via telephone to the mainframe up the hallway using the same 300
baud modems I had used in my fathers office.
Throughout Junior High I continued to build my circuits and write my BASIC programs,
anxiously awaiting each new issue of Popular Electronics to come to the local public
library for new circuit ideas. In reading that magazine I started to see more and
more advertisements and articles on the new “micro-computers”, and of course the
landmark issue for me was August 1976 (which I didn’t even see until school started
in September that year) whose cover article was “build your own computer for under
$80”. (That computer was, of course, the Cosmac Elf.) Well, although that project was very very far above me at that time, both
intellectually and financially, it served as a goal to aspire to. Although I had nowhere near $80 to even get the parts, I was
able to convince my parents to give me the (I think) $5.00 that it cost to get the manual for the 1802 processor, and I mailed
away for it.
Over the next year and a half, between studying that manual over and
over and repeatedly wearing out photocopies of the Popular Electronics ELF articles from the library, I
eventually made the transition from simple BASIC to an understanding of machine
code, and I grasped the principles of integrated circuits (which I promptly put
to work building all kinds of annoying things that flashed lights and made noises,
among other things.)
Starting in 1978, and throughout High School, I had friends from school (whose parents
were more able, and more inclined, to spend money on very expensive toys) who had
an Apple-II, an IMSAI 8080, and a TRS-80 Model I (two friends with those, actually),
all programmable in BASIC (the IMSAI via a Tarbell Cassette interface, the rest
with BASIC in ROM.) I was very jealous, as although I had more access to the local
Vo-Tech mainframe than any of them, and was learning COBOL, FORTRAN, and even Honeywell
assembler, my only “personal” computer at that time was a Logix-600.
So, after much
pleading, convincing, and conniving, I finally got my parents to lend me the $50
it would cost to get the parts to build the ELF. (I reduced cost by scrapping the
hex display in favor of 8 LED’s, and using a single $2.00 DIP switch instead of
8 expensive $2.00 toggle switches. (I had an angle up my sleeve anyway, which is
that mine would have a hex keypad option I would build out of an old scrapped calculator
keyboard I had, so I wouldn't need the DIP switches for anything but
keying in the monitor.) Anyway it probably took me six months from the time I got the parts
until I finally got it to work, but I did, and the rest is history. By the time
I graduated from High School I had added the Pixie graphic display, 3 whole kilobytes
of memory, and even added a serial UART to it so I could connect it to a Hazeltine
terminal my father had from the Vo-Tech for doing work from home. (Which I used
to practice my BASIC, since the ELF was strictly assembler until well after I was
out of High School, when I hand ported a Tiny-Basic to 1802 and burned it on an
EPROM.)
In the process of playing with friends machines throughout High School I also became
familiar with a lot of different architectures (S-100 vs. Apple vs. TRS-80, 8080/Z80
vs. 6502 vs. 1802) and became proficient at building varous devices and expansion
cards for different systems. The pinnacle accomplishment (other than my ELF) was the development
with a friend, around 1979, of an S-100 COLOR video graphics card based on a newly
released TI chip, for which we promptly wrote our very own rendition of the game
Missile Command in 8080 assembler, and played it with great glee. (Possibly the
only known instance of Missile Command for the IMSAI 8080, if another exists I’ve
never heard of it. That choice of game is especially ironic if you think about
it, considering the release years later of the movie Wargames.) We also developed some experimental analog to digital circuits
and used them to perform some very rudimentary speech input and waveform analysis
on the IMSAI, for which we were actually recognized with a regional Junior Academy
of Science award.
Well, when I say the rest is history, the rest is 25 more years of “playing” with
computers as much as I possibly could, my entire career has been centered around
computers of all sizes and shapes, from Micro to Mini to Mainframe - and although
it is almost all software now (I don’t spin a screwdriver or wield a wire-wrap tool
or soldering iron anywhere near as often as I did 25 years ago, but I do speak too
many computer languages to count easily) I did recently take a step back through
the time portal, and built a 30 year commemorative project - a completely hand wired
Apple-1 “prototype” - and then designed and built a couple “brand new” peripherals
for it. Although I had planned to put up this website for some time before
that, as a kind of personal catalog as much as anything, it was the Apple-1 projects
that inspired me to finally bite the bullet and put the site up, despite the fact
that that Apple could turn 40 before I actually have all my systems cataloged, and
all of the content completed I’d like to have. <G> But, I wanted
to share with everyone some of the fun I am having working on and restoring these
“Little Bits of History”. Thus I stop rambling
about myself here and encourage you to enjoy the
tour of
the site. (Additional history of my contact with specific systems can be found
in the personal history section of the page for that system.)