name: MC74F640 function: octal bus tranciver inverting with 3-state outputs package: DIP,20 manufacturer: motorola added-by: spamdogg +--()--+ T/R- | 1 20| Vcc A0 | 2 19| OE- A1 | 3 18| B0 A2 | 4 17| B1 A3 | 5 16| B2 A4 | 6 15| B3 A5 | 7 14| B4 A6 | 8 13| B5 A7 | 9 12| B6 GND |10 11| B7 +------+ This information was added by a third party and may be incorrect. This pinout came from the Chipdir: http://www.chipdir.org/