The Texas Instruments TI-99/4A is a home computer released in June 1981 and its a bunch of fun to code on.
I purchased this ancient relic from a hermit living in the distant lands we call The Finger Lakes. He had several of them stockpiled and was willing to sell it to me for a modest sum. It came with this bulky user manual which explained the variant of BASIC the system used called TI-BASIC. Its pretty different from the code used on modern day TI calculators, and in fact this was the last entry from Texas Instruments into the home computing market before they left the industry all together to focus on their calculators. It even comes with the original rebate, although I doubt I'm getting any money back at this point.
The TI-99 has no internal storage capacity, and so most programs that came with the system used a combination of cassettes and cartridges to load from and save to. The sale price in 1981 was around $500, which is about $1500 in 2020 dollars. Home computers were still a rarity, and not many Americans were willing to fork over that much money for this relatively new technology. Floppy drives existed- and were defintely the preferable data storage format- but most Americans already owned a cassette player. So the decision was made to include a cassette adapter to keep the price as affordable as possible.
This is the boot up screen of the TI-99. Looks very '80s', huh?
To load data to The TI-99, you have to type in 'OLD CS1'. CS1 stands for Cassette One. You then put in your tape and follow the on screen instructions.
I must say, there is something incredibly satisfying about 'unwinding' my software.
As the computer reads the encoded machine language from the tape, it makes a sound similar to a dialup modem. Sometimes it can take multiple tries to get a correct read from the tape. I'm using thinner tapes than they would have in 80s, so that could also have something to do with it. Once it finally does load, I'm able to see my code by typing in the command 'LIST'
Yep, its about 1200 lines. And each scrolls by on the screen one at a time. No, you can't scroll back up. If you want to see a specific line, you need to type in another command for the specific line, or type 'LIST' in again and hope you can spot the error as it whizes by. Despite being a relatively simple program, it took me about an hour just to type in to the computer. Most of my work was done on paper, and that took a few days to figure out. So, what does the code do?
Its a slot machine! No need to go to the casino, just play slots on your very own home computer. The future is now!
Well, I'm not very good at slots. But you get the point. This was an incredibly fun project, and it encouraged me to pick up some other old computers. As I build more programs, I'll be sure to share them here.