32K Non-Volatile Memory Updates

Here is a simple modification you can make to the NVM which enables you to remove an old battery and plug in a new one WITHOUT losing the program you have stored in it! It is amazing, but true. After removing the battery, you can diddley-bop around for 5 minutes (!) and still have time to plug in a new battery.

This mod is so good, we have started including it with all new RAMs we ship. However, if you have an older model, you can add it yourself by following the instructions below:

1. Locate the small capacitor which is immediately to the right of the write/protect switch.
2. If the capacitor is an electrolytic “can”, go no further. Your NVM is already fitted.
3. If the capacitor is a small tear-drop shape, remove it with a grounded soldering iron (the 3-prong type).

4, Replace it with a 220 uf, 16 volt electrolytic capacitor (Radio Shack #272-956). The negative lead of the cap should be connected to the hole which connects to the big fat ground trace. This is the hole which is located closest to the “DK” legend printed next to the Dock/Exrom Switch.

I find it simply amazing that this capacitor can keep memory alive for 5 minutes without any battery connected. It is testament to the infinitesimal current drain of the NVM, that a capacitor can hold the ram for so long.