Build information

A project log for Re-UD-80 - a larger display for Epson PX-4 / PX-8

The vintage Epson PX-4 and PX-8 computers have small LCD screens, with low contrast. This device fixes that problem.

fjkraanfjkraan 03/30/2024 at 19:180 Comments

Building information for the Re-UD-80 board

Power supply

The board is prepared for the classic 9V DC wall-brick, supplied through a barrel-jack 2.1/5.5mm with pin positive. The regulator has the same pin-out as the LM7805. There is little room for a cooling sink,  so a switching regulator is advised.
On the other hand, power consumption is modest, ~200mA, so it is feasible to power the board directly from a USB charger or power bank. Do not solder a 7805 and short its input solder pad to the output pad and directly connect 5V to the barrel-jack socket. This works quite well. I have yet to add a regulator to a board.


See the oval80replicaV0.10.connectors.pdf file (files section) for more info on what connector or jumper should do.

List of unstructured information and observations: