My Calculators

Texas Instruments

A family portrait of some of my TI calculators


The TI-30 was one of the first breakthrough calculators for TI. It was less expensive than previous models, and sold quite well. Originally selling for $25USD in 1976 (about $113 in 2020), it was much less expensive than similar models from HP and Casio, and sold for less than the price of a quality slide rule.

Click on the images for bigger versions. If for some reason you want even bigger ones, contact me for the originals which are a few megabytes each.

My TI-30 TI-30 


I was after one of these for quite a while; then I managed to snag one in very good condition that included the original carrying case and the Master Library Module. It also included quite a few blank magnetic cards for storing programs, and the original keycode overlay for the keypad.

Since then, I picked up the elusive Electronics Engineering Library Module, which I actually use from time to time. I replaced the original batteries with NiMH high-capacity, low self-discharge cells that should give it quite a lot more life.

My TI-59 TI-59 Carrying 
Case TI-59 with MLM The Elusive EE 
Module Some spare 
magnetic cards The module in 
the back of the calculator


This large, dual-hand calculator is an awesome programmable scientific calculator from the early 1990s. The LCD's contrast isn't great on my unit, so it's a bit hard to read the display unless it's under good lighting. I need to open it up and see if I can do anything about that.

My TI-92

SR-50, TI-55

These two calculators came from the same seller. Both need restoration. The TI-55 does work when powered externally, the SR-50 appears to not power on. Could be something simple, but I need to spend the time to open them up and check them out. The battery pack for the TI-55 should be easy to refurbish. The SR in SR-50 stands for Slide Rule, as TI orignally branded their calculators as "digital slide rules". It is actually the first pocket scientific calculator that TI released, in 1974. So it is almost 50 years old!



This Soviet-made programmable RPN scientific calculator is one of my favourites. This model is known to have flown on at least one Soyuz mission as a backup to the flight computer. It was able to execute code from external ROM modules, which is why it was feasible to use as a backup. It is one of the only calculators from that era (Western or otherwise) that had built-in EEPROM for program and/or data storage. It can only store just over 100 program steps, but it was definitely a nifty selling feature at the time. It originally sold for 115 Rubles. It's hard to do quick conversions, but that seems to be about the equivalent of $5USD in 2020. Pretty amazing that they got the price so low, but even so, it was an expensive item on a Soviet salary.

When I got it, the display was not working correctly at all. I spent some time talking to some Russian calculator collectors over on the calculator forum, and they told me to look for some new old stock displays on eBay, which I managed to find. I got 4 of them for a really good price. They told me that even the NOS displays can be flaky, but I guess I got lucky -- the first one I installed worked! And thank goodness, as the process of replacing the display was a bit of a pain.

MK-52 after 
being unpacked The nifty 
Cyrillic keypad Working display 
after replacement!