What is it?

These are DIY kits of an Amiga 500/500+ memory expansion designed by PeteAU on the EAB forum.

Why did you make it?

This expansion uses RAM chips from the old SIMM memory modules used on PCs in the late '90s-early '00s, which can be found quite easily on eBay or hopefully in your attic . Compatible chips should be all 42-pin EDO RAM chips in the SOJ package. Count carefully, because there are also 40-pin chips around, which are NOT compatible with this expansion.

What makes it special?

The expansion supports 3 different configurations:

• 512 KB slow or chip RAM for the A500 (depending on Agnus and mainboard revision), for 1 MB total RAM (requires a single RAM chip)
• 1 MB chip RAM expansion for the A500+, for 2 MB total chip RAM (requires 2 chips)
• 512 KB chip RAM + 1/1.5 MB slow RAM for the A500 (requires a suitable Agnus, usage of a Gary Adapter and 3/4 chips), for a total of 1 MB chip + 1/1.5 MB slow RAM (1.5 MB requires Kickstart >= 1.3, 1.2 only supports 1 MB)

The expansion can also provide an RTC (Real-Time Clock), but this is optional and not required for operation.

All PCBs come as an expansion board with the Gary Adapter tacked to it (see picture below). If you need the latter, you will have to separate the boards (look around for how to cut PCBs). If you don't need it, you can just leave it there and it won't hurt.

What's included?

Kits have been arranged in order to try to accommodate all configurations, see here for a detailed list of what is included in every kit.

All critical components come from a Reputable Source (capitalization is not casual). RTC chips are second hand "pulls" but are tested individually before shipping, so you are guaranteed to get a 100% working kit.

Note that I do not provide the actual RAM chips! You will have to find your own! I do not provide the RTC battery either (easily found in all shops for a couple bucks). Also, if you intend to use the Gary Adapter, you will need 3 wires for it, and female Dupont headers in case (male headers are included), or wires can be soldered directly to the board if you prefer.

Note that the final, soldered, ready-to-use product is NOT on sale. These are DIY kits which require soldering. They are not suitable for the faint-hearted, since they require soldering a lot of surface-mount components in the 0805 package.