The 80s digital logic PCBs and more precisely arcade game PCBs were laid out in a specific manner.
What is noticed as a PCB novice: 1) The (mostly 74 series TTL) ICs are laid out in a strict regular grid 2) There were quite thick power/ground planes around the board 3) There was quite a lot of space between ICs, much more than on later boards using DIP ICs *
- I do not know however if the later boards were multi-layer (>2) boards. The C64 board looks much more crowded, although from the same era.
Can anyone elaborate on why PCBs from that era were made like this?
What was a limitation of the design process (CAD/Manual) or manufacturing/assembly process?
Was the regular layout (point 1) only to make troubleshooting easier? I often read in service manuals things like: "Solution: Bad 74LS20 at location 3A"
Is there any read-up on the theory of these layout guidelines?