The big PC Board
gwhat
A long long time ago (40-45yrs) we selecting desk top computers( before PC’s) to do some scientific monitoring. We concluded the I/O for this project needed to include RS232 Communications with modem, 16 channels of analog input, 8 channels analog output, 16 digital inputs, 16 digital outputs, among other sundry features. None of these features were available in even a single chip format. The board size was 16” s 16”. The board manufacturer had only 2 sided technology, and was concerned about the manufacturing reliabilty of traces less than 40mm. All IC’s that were available had 100mm spacing and 50mm pads Well I set out to do the impossible, with out any layout software available, The layout was done with red and blue transparrent tape at a 4x scale. The two sides of the board were photographically separated and reduced (quite a feat in itself) Well the board worked after only 10 cuts and jumpers and the design served for over 10 years 100/s of boards were made. Nothing like the way a circuit is designed and boards layed out in the era. Wish I still had a picture of the board
- Shared October 11, 2012