Old School Microcomputer Programming - 8080 Style
@ danieljdick | Monday, Mar 22, 2021 | 9 minutes read | Update at Monday, Mar 22, 2021

I got into Microcomputer Programming the way I got into most everything else.

I got curious.

In 1974, I was a college student majoring in music and religion. Concerned what life as a traveling musician would do to my family, I left college after my first year and returned to Fresno to study Acoustics at Fresno City College.

Unfortunately, there was no Acoustics major so I was told to major in Architecture. One thing led to another as it always does, and this led to my taking Math, Physics, Engineering, and one programming course. Although I found Fortran IV extremely boring, I spent time in the computer lab first on my assignments, and then figuring out how BASIC programming worked.

My life as a hacker

At Fresno City College, I hacked my way into a tutorial system and used it to help me learn Math and Physics as well as BASIC programming. When I confessed that to one of my professors, he found it quite amusing and told me to go ahead and continue using the tutorials but not to tell others since they did not feel the tutorials were good enough for general use at school. Later that summer, I studied Systems Administration and COBOL Programming on a Honeywell system where I developed a silly game using sense-switches and the chain-line printer.

Now, I wanted to leave my college kid jobs washing dishes and selling clothes and electronics in department stores and go to work in a real computer programming job. And I was willing to take any programming job I could find.

8080 Microcomputer Programming in NorthStar BASIC

This is borrowed from Debut Vintage YouTube Channel

What is a Wang computer doing in a NorthStar BASIC section of this web page?

Well, I explored a job opportunity in programming at DCI or Data Consultants in Fresno. For a test, I was seated before a Wang computer and asked to create a finite element analysis program for designing wooden arches for supporting church roofs. I understood later the boss wanted to give me an impossible task I was sure to fail, but I failed to fail. And because I had put forth the effort, he offered me a programming job for $2/hour. And in exchange for that, I helped create the foundation that two multi-million dollar companies would fight over. I never realized this was an unusual challenge until much later when I was told.

(I am trying to find out where I got this picture from so I can acknowledge the source. Or I may need to look for another picture and source to acknowledge. I like giving credit where it is due.)

That was my beginning as a software developer. I built two systems in NorthStar Basic on a Processor Tech 8080 machine–one for auto financing and one for auto leasing. These would provide a screen for entering all of the data for a financial calculation except one missing value, and it would calculate the missing value quickly and accurately using a Newton-Raphson iteration as the calculation could not be performed algebraically alone. Then when the customer and seller agreed on the deal, the program would fill in the blanks of a standard bank contract.

Fun with Bills and Star Wars and Our Gang

I had two bosses named Bill at DCI, a Bill Putnam, and a Bill Pardini, and I thought they were both the greatest. Bill Putnam owned the company and Bill Pardini worked with me as his programmer to design the auto leasing and finance systems. But we also had our humorous times.

The Processor Tech system had an interactive Star Trek game written in machine language. Now, the video card had no graphics to speak of–only characters memory mapped to the screen. In BASIC, you could use peek or poke to read or write to the screen. So, Bill, being a rather sharp guy, searched for the name of the creator of the Star Trek program on screen and plugged his name into memory instead. Actually, he edited it on disk, so it came up with his name as the author, and we all got a laugh out of it.

So, wanting to play around with the same idea, I decided to change it to say “by Our Gang” replacing “Bill Pardini” with “Our Gang”. But I did it wrong and ended up with “by Eor Gangdini” somehow with a typo and a failure to write spaces over “dini”. We all had a hard time getting to where we could stop laughing as we would get each other started back up again.

Whoops! Where did our whole system go?

Well, after working hard and developing these two auto financing and leasing systems, we only had the 5 1/4 inch floppy disks for backing up the system. Bill had a demo for a potential customer the next morning, but somehow he accidentally overwrote the original copy of the program. That should be OK as we had a backup copy. But he apparently backed up the deletion as well. So the program was gone completely from the face of the earth, never to be recovered.

Since I had written the complete system and remembered much of it, I took the system home and worked on it all night, and by the next morning I had entered the program from memory. Actually, my rote memory is not that great. The reason I could remember the program and enter it all by hand was that my logical memory is quite strong. If I can understand how something works, I can usually recover or reinvent it inside out, upside down, backwards and have a functional version of it back and running in a very short amount of time.

So I tested it well, brought the system back into the office half asleep, surprised Bill, and sort of saved the day. Yet really, he is the hero in spite of his mistake as he was the one who came up with the idea to do this program, what it needed to do, and he is the one who sold it to the customers and eventually owned the company.

I found this picture on Dave Dunfield’s Classic Computer site.

From there, I developed accounting software for an elderly man, a nice man, but who would lean over my shoulder while blowing out cigar smoke while I was developing accounting programs for him in Business Basic on a Vector Graphics S-100 computer. I worked for him for money and later worked in return for a computer which I still have today. It had 24k of memory and CPU boards I could swap out for an 8080, 8085, or a Z80. And I thought I was getting rich working for $8/hour.

On that system, I worked on accounting programs such as GL, AP, AR, PR, Inventory and such. Later, I worked on an Employment Agency’s program again in BASIC for $20/hour and thought that was exorbitant. But my ex-boss who I worked for insisted I ask that much.

Order Entry and Payroll for International Peripheral Systems, Inc.

IPSI was a company that assembled and sold Xerox Diablo star-wheel printers. They needed modifications to their payroll system and needed an Order Entry system to be built. So I built them one.

One of the systems I worked on was an Imsai 8080 system.

This image is borrowed from Steve’s Old Computer Museum

Memories of rubber band fights and immaturity

A few fond memories I had were the rubber band fights we had the second that break times started. Clay would hide at his desk and start firing away, and we would fire back, and the boss' daughter, who was also our bookkeeper would give her ritual comment, “You guys are so immature!” And we were.

I felt a little guilty and spoiled as I seemed to be the only employee the boss never yelled at as he was quite vocal about getting things done on time and correctly. The rest of the team was great, but for some reason I never got yelled at.

Another funny memory I had was when we would forget to turn on the printer before turning on the Imsai system. The printer driver would get into a loop, and then you would have two choices: Stop the system and reboot, or hit the stop button, increase the program counter to get out of the printer loop, and restart. And then printing would resume without a problem.

The boss' daughter and the secretary got into a minor, but friendly disagreement about how an accounting calculation should be done. It really was simple algebra, and while I had respect for both women, I started to realize how lacking many Americans were in mathematics as I wondered how it came about that simple algebra became a controversial subject.

But then I ended up being a math major in college.

Picture of Cromemco System Three borrowed from Retro.moe" website.

Farm Accounting on Z-80 S-100 bus systems.

Later, I worked for Argos, a company that specialized in farm software such as farm accounting and irrigation scheduling. There, we worked in an in-house, fast, compiled language called “Argol”. Perhaps it was a play on “Algol”, but it was nothing like Algol. It was more like a macro assembler calling macros for math, the user interface, and report writing. Another programmer, Gary, and I worked together on the accounting software until the owner of the company started a project for irrigation scheduling.

An irrigation specialist with his PhD in Agriculture worked with me on identifying variables related to weather, humidity, evapotransporation, and such, and I found it a joy to work on the project until this gentleman began insisting on some non-normalized entry of data leading to potential ambiguities. This was not something related to double-entry where two people enter data and the system makes sure things are consistent for security. This was a sort of sloppy entering of the same data by hand in multiple places, and I felt this put the system at risk of serious errors. Since we could not agree, we parted ways and I went to work for Fresno Unified School District.

worked on developing and modifying and enhancing accounting software for a couple companies later got involved in Farm Accounting and Irrigation Scheduling.

Copyright 2021 Dan Dick; all rights reserved