Last Updated or created 2024-06-05

For my 68000 POC I’ll need a way to test Address and Data buses. Something I also wanted for my 6502.

So I drew a schematic to make a generic bus manipulator.
(Address, Data and some control lines)

Devices I want to control:

• 6502 – 16 addresses and 8 bit data
• 6800 – 24 address lines and 16 bits data
• 808x
• LCD Displays – 8 bit data – enable, read/write and register select
• SID Music Chip, AY-3-8910 Music chip

I will be using 8 input switches I can latch into 74HC373 chips.
(3x 8 bit for addresses, or 2x 8 bit and extra control lines + 2x 8 bit datalines)
Using ULN2804A darlingtons I can use ledbars to display the bus data AND the latched data.
Using 5 pushbuttons I can choose which one (or multiple banks will be latched.
Other 5 buttons shall control the OUTPUT enable (OE), which also can be toggled using 1 master switch.
(Not yet in the schematic)

After testing, I will put the Kicad files online.