2MB RAM Amiga 500+ chip RAM mod

Warning

Only attempt modification of your Amiga if you have the correct tools and are confident in your soldering skills.

Information

This page describes how to modify your Amiga 500+ to get extra chip RAM and slow/ranger RAM at the same time with the BooBip 2MB upgrade.

The Amiga 500+ memory configuration differers from an Amiga 500. It uses both RAS lines and has extra CAS lines for the memory expansion port allowing a 1MB memory expansion. This modification swaps the memory around so the 2MB on the upgrade card becomes 2MB chip memory and the 1MB on the Amiga motherboard becomes the slow/ranger RAM.

The Gary adapter must be fitted if you perform this mod. If you don't do the mod then do not fit the Gary adapter to an Amiga 500+.

Requirements

  • Amiga 500+
  • BooBip 2MB memory upgrade & Gary adapter

Mod

Note: route the mod wires to fit through the gap between the upper and lower RF shielding.

  1. Either a) carefully cut track shown
    or b) carefully lift U34 pin 2
  2. Solder a jumper wire (shorter) to U32 pin 2
  3. Connect the jumper wire to pin 1 of J3 on the 2MB memory upgrade
  4. Solder a jumper wire (longer) to U34 pin 2
  5. Connect the jumper wire to pin 2 of J3 on the 2MB memory upgrade
  6. Connect the Gary adapter following the 2MB upgrade installation instructions

Images

Cut track

2MB-a500+_mod_cut.jpg

Solder wires

2MB-a500+_mod_wires.jpg

Installed

2MB-Installed_a500+.jpg

Testing

Test with Keir Fraser's SysTest (or your favourite) memory test. Run avail from the Workbench shell to confirm the correct memory configuration is being detected.

More information in the 2MB memory upgrade installation instructions.