Power Supply

Model 4/4D/4P Power Supply

Jay Newirth (of newSOFT) is now selling 2 versions of the Model 4 power supply using modern power supply components while retaining the use of the existing wiring inside the various Model 4 computers. He has one for the Model 4P (which has a 12v connector to attach a fan if so desired) and one for the Model 4 (GA), 4 (NGA), and 4D unit which is now a simple “pull out the old and put in the new” design. It’s size is the exact same size as the original power supply and should therefore fit.

For more information contact Jay either at JAYNEWIRTH@VERIZON.NET or visit his website at NewSoft Store.


The Model 4/4D/4P uses 4164 chips. These are still generally available although you need to be careful of the source. Fake chips (or chips that will fail) are very much a risk, so it is important to source them from someone who has run them through a RAM tester. There are people who sell based on how much they have on hand, and you can always try your luck on eBay.