Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcsun!unido!tub!tmpmbx!netmbx!hase From: hase@netmbx.UUCP (Hartmut Semken) Newsgroups: comp.sys.atari.st Subject: Re: Can I separate the keyboard from the computer? Message-ID: <3561@netmbx.UUCP> Date: 4 Oct 89 16:27:16 GMT References: Reply-To: hase@netmbx.UUCP (Hartmut Semken) Distribution: comp Organization: netmbx Public Access Unix, Berlin, West Germany Lines: 31 In article loki@moncam.co.uk (Never Kid A Kidder) writes: >Next question: I've seen inside my 520 ST, and I've seen the 17 wire >connection from the keyboard to the rest of the computer. But only 5 connect the keyboard subsystem to the main processor > Now I would >like to make the keyboard separate, but I don't know if adding a whole >length of cable (say two metres) will affect the operation. Has >anyone else tried this, or can anyone say if the connection needs to be >as short as it already is? My cable is 1.5 meters long. Works fine: Find out the 5 wires for the serial interface: Send Data, Receive Data, +5 Volts, Ground and -RESET. Connect two 9-pin D-Sub connectors to the 17-wire connector. Now You connect Mouse an joystick to the keyboard. If You need a real long cable, use line drivers for the serial lines (74 07 and pullups or the like). I use 7407 and a pullup to +12 Volts as sender and some 40XX CMOS chip as level converter at the receiving end of the line (makes 2 TTLs and 2 CMOSses); I use the +12 Volt for power, too. My keyboard has a 7805, so it gets real +5 V, not just 4.something. hase -- Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP Dennis had stepped up into the top seat whet its founder had died of a lethal overdose of brick wall, taken while under the influence of a Ferrari and a bottle of tequila. (Douglas Adams; the long dark teatime...)