You should be really careful about connecting wires to those small holes on the PCB itself, those are likely vias (connecting top and bottom traces of the PCB) and you may end up short circuiting something resulting in damaged components! If you connect an output pin of the CPU to +5V and the CPU then tries to pull it low, the output stage on that pin could be permanently damaged! Also, yes you can certainty get those 74xx series IC-chips even today (I have used a bunch of them to create my own 8-bit CPU like Ben Eater did). Just remember that the 74xx series only run 0-5V and NOT +/- 12 V! - Those voltages are usually only used for operational amplifiers or similar analogue systems.
@jefftranter made a video about the 3200 at ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eIInXZuFsRQ.html and another about the 3400 at ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-EjYpuwnf2wM.html
Looks more like late seventies/early eighties , certainly NOT sixties, all those IC's and microprocessors didn't exist back then, only transistors, diodes, resistors, capacitors, potentiometers and that kinda stuff
Yeah, I know the one on the right is not 60's, I was talking about the one on the left (The $20 one) It doesn't have any IC's and microprocessors. The one on the right is probably late 70's, as you said.
