No more rotten cables, presumably same method for sdl board.
As the original cable of my Model M was rotten and I don't want to install USB conversion just yet I decided to install a new cable however shipping a new cable from unicamp and shipping from the US to the UK cost a fortune so I decided to fix it myself.
Straight to topic, my Model M from 95 has a 4-pin connector and Crimp Ring Terminal on grounding so the quest is to know which wire goes where.
Materials needed:
Multimeter
Oscilloscope
Mini-din 6-pin socket(male or female)
PS/2 extension cable
Basic knowledge of how DC circuit works.
Connect original cable, disconnected from the keyboard
Use multimeter to find Vcc 5v, test each wire. -5v means your multimeter's mAVΩ(usually red) probe is not on Vcc and one of the wire being measured is Vcc and 5v without the minus sign means your mAVΩ probe is touching Vcc.
Attach a oscilloscope probe's ground to ground wire, use probe to check each wire until you see square wave. That's clock.
My cable was:
Black Vcc
Red Clock
White Ground
Yellow Data
Colour coding could be different between batch to batch, do not apply this chart without testing.
Cut original cable and preserve old connector or install new connectors onto the control board at your discretion.
PS/2 socket is much larger then mini USB or USB type C socket, either let the PS/2 connector to be hanging outside or stored inside and leave the new cable to be attached or drill holes on the case and mount the new socket.
It's my first post here, hello everyone. I learnt some from assembling a few electronics kit but I don't know very much about electrics yet please be careful, not fully follow my notes without some thinking.
