Xref: utzoo comp.terminals:2748 sci.med:24006 comp.cog-eng:1908 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!motcsd!lance From: lance@motcsd.csd.mot.com (lance.norskog) Newsgroups: comp.terminals,sci.med,comp.cog-eng Subject: Re: One handed UNIX, Emacs for disabled person? Message-ID: <3557@motcsd.csd.mot.com> Date: 2 Apr 91 22:53:46 GMT References: Followup-To: comp.terminals Organization: Motorola CSD, Cupertino CA Lines: 52 Dan_Jacobson@ATT.COM writes: >Hello. Has anybody got ideas for using mainframe UNIX or computers in >general for a disabled person with use of only the right hand? ... > [ also asks about text editors ] I think I'm getting Carpal Tunnel Syndrome, so I'm building myself a chord keyboard. This consists of 5 buttons on a flat mounting, one for each digit. I'm adding a space bar. I'm mounting it in a 5"x7"x1" project box. I'm interfacing it all to an IBM PC. With an IBM PC parallel port, pull an open switch to ground and a closed switch to 5V. Run all 6 switches through a 7405 hex open-collector inverter, wire-NOR all the outputs, and you get a switch-down interrupt line on the parallel port. (The interrupt handler has to poll until a switch goes up. You can avoid this inefficiency with many chips instead of one: debounce the switch inputs, sample&hold all switch-downs, any interrupt on any switch-up. I'm too lazy to do all this design & wiring.) Now for graphics input: Get a Konami Nintendo-compatible ZapGun Helmet ($40). The Nintendo ZapGun is a light pen with a narrow lens in the barrel. The Konami Helmet puts the lens in a monocle, and a binary switch in a microphone. Any noise closes the switch. You also get stereo headphones. You should be able to interface the light pen to real, IBM-compatible Hercules, CGA, and EGA display adapters. One VGA chip manufacturer, Cirrus (Fremont, CA) claims to support light pens. I'm researching this one. You won't be able to draw free-hand with such a head-mouse, but you should be able to select screen buttons. An alternative for graphics input is something underfoot, if the disabled person has use of the peds. The IBM joystick card gives your 4 switch inputs and 4 resistor A-D inputs. Dr. Douglas Englebart, inventor of the chord keyboard, mouse, WIMP interface, and many other things, claimed in a recent seminar that the chord keyboard group ran a big experiment to determine the difficulty of learning a chord keyboard. They hired a bunch of office temps and carefully did the whole experimental-control group protocol. One group got special hands-on training, the other group got written instructions and were left alone. Both groups were keying away madly in 2 hours, and the experiment was a washout. Chord keyboards are easy. Dr. Englebart sat there chording with his left hand, mousing with his right, and talking simultaneously, showing off a really slick hypertext system his group wrote 25 years ago. It was very impressive. Good luck, Lance Norskog