I again wasn’t looking to start another calculator project when this Burroughs C5155 calculator showed up in one of my automated searches. The price including shipping was a bargain, so I purchased it.

Barbouri's Electronics Projects
Restoring vintage electronics along with designing and building new circuits. One eye looking into the past, the other looking into the future.
I again wasn’t looking to start another calculator project when this Burroughs C5155 calculator showed up in one of my automated searches. The price including shipping was a bargain, so I purchased it.
I managed to snag a Monroe 430 calculator that was in good condition and a reasonable price. The Monroe 430 is 14 digit four-function calculator with memory, percent, and a few other extras. I have worked on a model 425 and 420 in the past so I kind of knew what I was getting into, especially the lack of documentation.
An early handheld calculator from 1974, with a 10 digit Panaplex display and rechargeable battery.
As I continue searching for Monroe 400 series calculators, I came across this Monroe model 40 calculator at a reasonable price, with a few small issues.
Normally I don’t have an interest in handheld calculators as most are too new. This one caught my eye with it’s unique styling and 10 digit Neon Panaplex II display.
A recent addition to the desktop calculator collection is the Canon Canola L100A desktop 10 digit gas discharge display calculator. This unit was purchased as a working calculator, and was in good shape except the heavy yellowing of the beige upper case..
It wasn’t the exact calculator that I was looking for, but the purchase was well worth the price paid for it. The model 425 from Litton Monroe is a 12 digit Panaplex display with memory calculator.
The newest addition to my small calculator collection is an APF Mark 1 desktop unit. I found it on Ebay a few dozen miles from where I live. As usual it was untested, as it did not have a power cord, and other than being dirty it looked in good condition.