MacEffects once sold an 8MB RAM Card for the Macintosh Portable. TechKnight did the original design and licensed it to MacEffects for mass distribution. That card went out of stock around 2021, and due to chip sourcing issues, it probably won't be in stock in the future.
Some people who...
Although this schematic set only covers the non-backlit 5120, much is similar to the 5126. For example, the audio section matches my 5126 Portable quite well. The Hybrid section is of course different.
To download, click the blue button in the upper right corner.