I did more or less the same thing, as did lots of other people.
Wiring the serial or parallell port to something wasn't hard. Instructions for bit banging them where generally found in the library (paper books). Serial had weird voltages but was near indestructible. Parallel was TTL just like anything else digital, so some 74 ICs got you mostly there.
The era where you basically needed to solder if you wanted a computer was just over, so electronic knowledge was still easy to find.
Wiring the serial or parallell port to something wasn't hard. Instructions for bit banging them where generally found in the library (paper books). Serial had weird voltages but was near indestructible. Parallel was TTL just like anything else digital, so some 74 ICs got you mostly there.
The era where you basically needed to solder if you wanted a computer was just over, so electronic knowledge was still easy to find.