Kwakkelflap: tools for the IT pro

Wednesday, June 11, 2008

HP 48G RAM upgrade

One of the things on my desk that I use all the time is my old faithful HP 48G calculator. I originally bought it some 15 years ago when I was a student. The HP uses Reverse Polish Notation which works great. I'm so used to working in RPN that I simply hate using regular calculators. That's one of the biggest reasons I still use it today cause, let's face it, I don't do Fourier or Laplace transforms these days.

The only problem I had with the machine was that I purchased the "budget" version ($200 on a student budget 15 years ago wasn't exactly cheap) which had 32K RAM. This means it can hold only 1 program most of the time. Some programs don't even fit at all. But then I stumbled on this page which explains the process of upgrading the HP 48G to 256K RAM. I loved the idea, but I'm not the most skilled person when it comes to soldering SMD chips or any other delicate operation for that matter. So I was a little hesitant to do this cause there was a possibility of ruining my beloved calculator. But I figured I'd try anyway.

I stopped after soldering the 128K RAM chip cause that was difficult enough for me and they warn people that soldering another 128K chip on top was very hard. The result: a HP 48G with 128KB RAM and a very ugly front. I don't mind the front at all cause when people ask me what I did to my calculator, I have a very nerdy story to tell.