ocr: F6FBB PORT MULTIPLEXER Drawn by G6WHL a GB7KLY 1993 21 2 31 e 3 IC1 =4 4050 4 + a - IC2 =4052 J 0000 la 6 e VEE 4K7 201 201 COMPUTER 470 81 e 81 - e o o PORT 470 le - e e 12 470 e - 4K7 oo TNC1 e TNC2 o 3 3L 14 470 o e - e 470 IC1A 13 15 o DB25 - e DB25 3 oo IC2 11 o 2 71 - - a 20 4K7 4K7 IC1B 10 9 4052 5 4K7, 4K7, e o 2 4K7, oo - 22k2 6 4K7, oo o VDD VEE - o oo o PORT IC1C - oo le 4 e 2k2 +12v- OVUD 6 o ICID 150R o #6.8v 20 201 2k2 100n 100n VEE 12 11 470uT 8 e 8 DATA IC1E *6.8v - a o o -12v- 150R VEE le o TNC3 le 2k2 o TNC4 l 14 VSS e DB25 e DB25 IC1F
