ZX Spectrum Upper RAM Module:
This module can be used to replace the eight 4532 (or equivalent) ICs that form the upper 32 kilobytes of RAM in a 48K ZX Spectrum computer or to upgrade a 16K ZX Spectrum to a 48K model. The ZX Spectrum must be an issue 2 or later.
The upper RAM support ICs IC23, IC24, IC25 and IC26 must be present and functioning. It will probably be necessary to fit these in addition to this module when upgrading a 16K Spectrum to a 48K model.
Click here for the installation instructions.
Buy:
The ZX Spectrum upper RAM module is no longer available, but might be again later this year.