=== Happy Computer 8bit Printer Port upgrade (DIY) ===
A good method to upgrade to full 8bit has been described in the german magazine "Happy Computer Sonderheft 2/85 and 4/86":
* Disconnect the D7 pin from ground, and wire it to the [[8255|PIO]]s Tape WR DATA pin instead (That is, Pin 12 of the 8255 chip).