Originally Posted by Just Desserts
The M6803 in the keyboard bit-bangs serial over to the M6803 in the "TDS box".
The M6803 in the TDS box hands bytes over to a SCN2681 DUART in the same box.
The DUART in the TDS box sends serial over to a 6850 ACIA in the computer crate.
The M68000 in the computer crate reads bytes from the 6850 ACIA and puts them on-screen.

You can't explain that.

That is some quality Rube Goldberg engineering.