Group Actions
Engagement
  • Author Author: ralphjy
  • Date Created: Date Created
  • Views 3093 views
  • Likes 12 likes
  • Comments 13 comments
Related
Recommended

Pong is Alive

ralphjy

As part of the Hardware Hacking Challenge I thought that I'd try to resurrect a Pong game that I built back in 1978.  My intro blog is here: Pong Game Circa 1978

 

Since it came out of my junk box and seemed to be in poor condition I thought that I probably should have proof of life before I invested too much effort in restoring it.  I was somewhat surprised that the 30 AWG wirewrap wire that I had used had oxidized and become brittle.  Some of the wires were actually broken.  I still use 28 AWG wire of the same vintage and the unused wire seems like new.  I guess maybe the wire may have reacted with the metallization of the wirewrap pins.  Anyway, I decided I should rebuild the circuit from scratch - just reusing the ICs and the crystal.

 

So, I cut the circuit board out of the case (who used connectors back then image).

 

Top of the board:

image

 

  • Pong chip AY-3-8500-1 (-1 for NTSC)  Date code 7707
  • 4072 CMOS Dual 4 input NOR
  • 4001 CMOS Quad 2 input NOR (might be a 4011 Quad NAND - can't read the marking)
  • 2MHz crystal
  • 6.3V zener - I had used 9V batteries for power (I probably could have run the parts directly but the typical voltage for the Pong chip is +6V to +7V)

 

The bottom of the board:  You can see the blackened wire ends wrapped on the pins.

image

 

Switches and jacks viewed from inside the case:

image

 

To verify life I thought that I'd just power it up and verify the clock circuit and that the video sync and composite outputs were working.

 

2 MHz oscillator waveform:

image

 

Video sync:

image

 

Composite video:

image

 

So looks good to proceed.  Hope to have a functioning game soon.  I just realized that I'll have to scare up a composite monitor......

Parents

  • It is encouraging to see that technology this old can still be brought back to life. I was intrigued by the wire wrap as I started in my design days using wire wrap, mainly because it didn't use a soldering iron or PCB. I made an 8088 based microcomputer using wirewrap and it worked, although sadly I no longer have it as it went to the great scrap heap in the sky when 8088s were replaced by PICs. You might struggle to find a composite monitor as most CRT based system seem to have been scrapped.

     

    Dubbie

  • in reply to dubbie

    Turns out that I found that I still have a 23" Samsung LCD TV that my boys used to use for video games and that has a composite input.  All of my CRT monitors and TVs have been recycled long ago - I probably should have kept my NEC green/black monitor as that was a classic. 

Comment Children
No Data