Texas Instruments TI-58

I really enjoyed learning programming on the TI-57 but I soon could not fit the programs I wanted to run in it’s limited 50 program steps. I saw an ad for the ‘step-up’ TI-58. Now here was a machine with some power!

Here’s the fantastic instruction manual that came with the TI-58.

Along with the TI-58 you got a ROM module that fit’s into a compartment in the back of the unit. Free with the TI-58 is the Master Library Module with 25 built-in useful programs. Other modules were available for different fields of interest such as real estate, business, math, etc., for $35. each. A booklet describing the programs on the ROM chip and 25 reference cards accompanied each ROM. The TI-58 itself could be programmed with up to 480 program steps and up to 60 memories.

It also would work on the companion PC100A printer cradle attachment as did the TI-59 and a few other models.

Texas Instruments TI-59 & PC100A Printer Cradle Attachment

Soon I found the TI-58 had one huge drawback. Oh, it was powerful what with it’s 480 program steps and 60 memories, but if you turned the calculator off, you lost all your work! No matter how complex and no matter how many hours you spent on your program – you had to write it all down or it would be lost. Even writing it all down didn’t save you – but at least you had the ready made operations to key back in again.

I really liked the TI-58, but I needed something more.

Enter the TI-59, the big daddy! Not only did it increase the storage space to a whopping 960 program steps and 100 memories, but it also came with a magnetic card read/write mechanism. You could now save your precious programs onto little 1” x 3” magnetic cards. No more keying the programs back in every time the calculator was shut off. Just insert your card and your program was almost instantly read into memory.

 

Now we’re getting somewhere! But there’s more! The TI-58 & TI-59 had the ability to work with the PC100A printer cradle attachment using alphanumeric characters. A,B,C,D etc. Why you could spell your name with this thing!

Not bad for a ‘calculator’, I’d say!

So, now we have almost a thousand program steps and 100 memories to work with. The ability to print all your calculations and use a paper trail for debugging your programs for the printer would list your entire program for you, if needed. What the alphanumeric gave you was basically the ability to use English to ‘talk’ to your TI. It could now say things like - “Hey, guess my number between 1 and 1,000. It could play games like blackjack or ask you to enter numbers and figures using words. That sure made for far more fun in programming.

 

This was 1977 mind you. It was a time on the brink of an computer explosion that was just around the corner.

Three personal home computers emerged on the market before 1980. They were the Apple II, The Commodore PET, and the Radio Shack TRS-80 Model 1.

I happened to be driving by a Radio Shack store in 1978 and there was a sign in the window that read “TRS-80 Model 1 Home Computers now in stock!” This would be my next step UP.

It’s been 34 years since I had those awesome TI Programmable Calculators. They had long been out of mind for me, but not forgotten. A couple years back I went searching until I found fully working models of all those old programmable calcs I spent so many pleasant hours with – the TI-57, the TI-58, and the TI-59 along with the PC100A printer.

Basically, I’m retired now but . . . . back in business . . . . :)

Troubles & Repair of the TI-59

Working on the TI’s. So I’m happily living right along in my life – what with my stable of vintage Texas Instruments TI programmable calcs – and I take them out to charge up the battery packs and generally just play around with them, the TI-57, TI-58, & TI-59 along with the PC100A printer cradle. I charged up the 58 & 59’s battery packs and was playing around with the 58 off the cradle and with it on battery power, when the display slowly faded. I’d only been using it on battery power for a few minutes. I quickly switched out the 58’s battery pack with the 59’s and was back in business. Five minutes later the display faded out once more. Well, it was all good while it lasted.

 

Apparently these two calcs with their battery packs have sat for over 30 years without a charge and since I’ve owned them and charged them, oh, maybe a half dozen times – that must have done them in. Well, even eBay’s going rate is $40. for a replacement battery pack that’ll fit. Same pack fits either unit. It’s just a plastic box with 3 NI-CD’s fitted. It’s a custom case though and to replace the batteries you need to kind of cut the battery case open and separate the metal contacts then solder some leads to connect the batteries and then sort of glue the case back together. So, basically the $40. is because it’s a bit labor intensive. Well, I’m giving a go to doing my own rebuild rather than paying $40. to someone else for basically $10. worth of batteries.

In replacing my 34 year old battery pack with new NiCd batteries I followed instruction pictures I found on the Internet and cut the case as shown. You can see why the battery pack was not holding a charge anymore because the batteries were starting to leak. It’s funny that they took 34 years to get to this point. I’ll bet they didn’t start to corrode until I started charging them up after they’d sat so many years. Now I need to go buy some batteries, but the repair article stated to get a phone battery pack with solder tabs – and the only place you’ll come up with that type is on the Internet. In the mean time I’ve fashioned just a 3.6v phone battery I had sitting around. Most phone batt. packs have a plug like the one I am using in the TI-59 now.

Then I decided that since that was working pretty well except I had no battery compartment door now. The original battery pack is built right into the door. So, I modified the battery holder slightly so it would hold the phone battery I’m already using. Now I have the battery inside and the compartment door closes just fine. - -

Well, it did until I wanted to take a nice picture of my handy work, and I messed it up. I broke the locking tab and now I have to put a piece of scotch tape on the door to hold it closed. Bummer. I hate plastic tabs, they break too easily!

Anyway, I did get the picture showing how I’ve moved the wires inside and how I can still hook the TI to the printer, (if I can figure out why now the TI-59 doesn’t want to work when hooked to the printer!) It works fine off the battery pack though. That’s another ‘thing’ to try to fix. Also when I get my new battery pack done – it can replace the phone battery without having to change a thing. Just move the wires away and tape the ends inside.

Here’s the back closed now –

and I’ve replaced the unsightly clear tape with black electrical tape so it’s barely noticeable. I have another battery pack that I will be more careful with when I rebuilt it and I think I’ll just regulate that to the TI-58 and use the TI-59 this way for now. At least until I can figure out the problem with it not working on the printer cradle. I took it all apart even and could see no reason for it’s not working on the cradle. All it has to do is make contact with the two tabs and that it did – but still wasn’t getting any power. Go figure?