Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site brl-tgr.ARPA Path: utzoo!watmath!clyde!akgua!sdcsvax!sdcrdcf!hplabs!hao!seismo!brl-tgr!spangler From: spangler@brl-tgr.ARPA (James J. Spangler ) Newsgroups: net.micro.zx Subject: Reply on how to drive leds Message-ID: <4868@brl-tgr.ARPA> Date: Tue, 25-Sep-84 09:12:40 EDT Article-I.D.: brl-tgr.4868 Posted: Tue Sep 25 09:12:40 1984 Date-Received: Sat, 29-Sep-84 09:56:26 EDT Organization: Ballistics Research Lab Lines: 9 I have been expermenting with zx81's and find that using a 8255 I/O chip is the best way for me. It has 24 I/O lines that can drive a 5 volt logic level, which can be used to drive leds, scr's, and triac's. Besides using the 8255 you would need address decoders, which can be done with a 74LS138 and a few other 74's. I have also tried voice interfacing using the GE SP-0256 which seems to work well. Jim