Saturday, January 4, 2014

My First Computers

I started another blog entry but it was getting too long, so I decided to extract part of it and create a short entry describing my first computers.  Yes, I am dating myself.  Yes, my first computer was ANCIENT by today's standards, however I worked with a lady who started programming in the 1960s using really ancient systems.  Later she got to use some fast computers like one of the ones she programmed at NCAR, a Cray 1 which was in the Smithsonian Air and Space Museum in downtown DC.

Initially, my best friend and I tried to build a computer after reading the January, 1975 Popular Electronic article about the MITS Altair 8800.  We got a few chips including an Intel 8080, but it was way too difficult (circa 1976).  I also get several boxes of old logic cards from UF, but they were too ancient and we couldn't use them to build a computer.  Later I did use some of the logic cards to build a binary digital clock which is on my desk today (big, cool, but no longer functional).  My friend even got part of the front panel from an old IBM mainframe with lights and big paddle switches which would look great in a SiFi movie.  We eventually gave up.

After giving up trying to build a computer ourselves, I decided to buy a kit.  As a result, my first computer was a Netronic Explorer 85 (magazine ad) circa 1979.  The CPU was an Intel 8085 which was compatible with the Intel 8080.  I built my computer from a kit while at the University of Florida.  I didn't have a compiler or even an assembler, so I had to write my assembly code on paper, look up the opcodes, compute the offsets, then type in the HEX values on the keypad (or walk 20 miles barefoot in the snow up mountains to access the mainframe - wait, I was in Florida).  I had a motherboard with 256 bytes of RAM and a 3MHz CPU, HEX keypad with HEX display, and S-100 bus interface.  I also built a S-100 64K memory card, a S-100 64-column video card with NTSC video output, and an ASCII keyboard (got it cheap as it did not include the Enter key).  My display was initially a small, tube B/W TV my dad won from the local Gulf filling station a few years earlier.  I stored my programs on magnetic tape using an old, mono open-reel tape drive or cassettes.  My interface with the outside world was a 300-baud Novation CAT Acoutic Coupler Modem (dial the number, then put phone handset in the "ears" to connect to the mainframe at NERDC).  My total investment for this very-slow computer was $800-900 (as much as $2500 by today's standards, so I drove a very old, rusty car).  I still have this computer in my attic, so I'll have to get it down and take pictures of this antique.  No, I do not plan on powering it up, as my smoke detectors do not need testing (they get tested often enough when we cook).

The nice thing about this computer was that I had it in my room at the SAE house on campus in 1979-1980. As far as I know, I had the first computer in ANY fraternity house on campus at the University of Florida.  I could be in my room, drinking a beer and programming on the mainframe while my friends were waiting in line at the card punches....

Not long before I got my BSEE, I upgraded to an Apple II  This had 48K RAM, two floppy drives, an 80 column card, printer, and even a Z-80 SoftCard with UCSD Pascal.  Total cost of this was about $2400.  I also built and tested an I/O card with digital I/O for the Apple II (today, this would be GPIO).  I had fun with this computer, but it was not very reliable.  The best that it EVER ran was in the Spring of 1982 on the porch in Yankeetown when the air temp was about 45F (could it possibly have been a temperature problem?).

After graduating college, I moved to Boca Raton, soon to be the home of the IBM PC.  I was WAY of out place with an inferior Apple computer (or so I was told), so I sold the Applie II for $1200 and bought a second-hand clone of a first-generation Compaq PC for about $2400.  This was a 4.77 MHz, single case system with a high-resolution green screen in the middle of the case and a single floppy disk on one side. Later, I added a 40MB hard disk and even a 10-base2 Ethernet card to this computer. In 1989, I was using this computer to read the news on the online Prodigy Service when I heard about the death of Ferdinand Marcos (husband of Imelda Marcos, the envy of many with her 2700 pairs of shoes).

All of these computers are nowhere near as powerful as an Arduino, much less a Raspberry Pi or BeagleBone Black ($35-45).  None of these computers were capable of running an O/S like Linux....

Yes, computers have come a LONG way in a very short timeframe.  If you are programming computers, learn how to really use the computer, and not just let the language do everything for you.  You will be a better programmer as a result.

My next post will be about the open source hardware including the Arduino, BeagleBone Black, and Papilio (and hackable systems like the Raspberry Pi)!

1 comment:

  1. I remember you trying to build your own computer! Wow, look what perseverance did for you! You really learned all of this from the ground up. I'm sure you've proven the 10,000 hours to mastery theory!