Most classic Galaksija computers left the factory without an expansion port connector. This board fixes that: a two-layer PCB that solders onto the top of the one-sided motherboard and presents a proper 44-contact card edge, 22 fingers per side at 2.54 mm pitch.

It stays backward compatible with the original edge connector while adding signals the 1984 design left out — INT-, RD-, RESET-, CLK and a VCC rail — plus seven extra ground contacts. Those five added signals are not routed from the 31-pin motherboard row; you hand-wire them to labelled top-side solder pads.

Two depths are offered. The deep variant's tongue protrudes about 5 mm further; pick it if your case has thick walls or a tight expansion slot opening, and the shallow one if the motherboard sits close to a thin wall. The two boards are electrically identical.

Orientation matters. Solder the board on backwards and you risk damaging both the motherboard and whatever you plug in, so confirm which face is the top before applying heat. The mounting holes may not line up with every original one-sided motherboard, but the solder joints alone hold it firmly.

The board carries no components at all, so order it as a bare PCB with no assembly. Since the edge fingers are a sliding wear surface, ENIG or hard gold is worth the small premium over HASL.

This is just sharing the project from https://github.com/DigitalVS/Galaksija-Resources/tree/main/Expansion%20Slot%20PCB — all design credit goes to Vitomir Spasojević (DigitalVS), released under the MIT License.