With the talk about calculators and all the RPN rubbish
![Evil >:D](https://www.eevblog.com/forum/Smileys/default/xevil.gif.pagespeed.ic.tdrs7Uj5gu.png)
going around here of late, I decided that maybe it would be a good idea to start the restoration of some the calculators I acquired a while back with that in mind These being namely a Commodore PR100 purchased new many years ago but the internal rechargeable batteries died and a Texas Ti58 and Ti59 which were purchased a few years ago as restoration projects.
The PR100 is now up and running nicely, just have to find the mains' adaptor for it and remember how to program it, a couple pics below.
The Ti58 is also fixed and working (I have a master library module for this somewhere) but I need to get a 2 pin plug in order to recharge the battery without having to open the back each time to clip the crock clips from my bench supply up to it. These Texas calculators of the time were different from the rest, they used a mains transformer and took low voltage AC into the calculator via the 2 pin interface onto 4 diodes in bridge configuration. I suppose I could dremmel the side wall just below the card reader to a suitable thickness to accommodate a 2.5 or 3.5mm jack socket and feed a 6VDC into the calculator directly onto the back of the connections to the 2pin interface and the volt drop across the diodes will reduce the voltage fed to the batteries to approx 4.8V. Does anyone know where I could obtain these 2 pin plugs from to fit the interface?
The Ti59 currently has a keyboard fault, only certain keys are being read by the system so more work is required on this one.
![](https://i.imgur.com/ch83eP5m.jpg)
![](https://i.imgur.com/L4u4IRRm.jpg)