Newsgroups: comp.sys.ibm.pc.hardware
Subject: Twiddler
Summary: anyone reverse engineer it? or even use it?
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Followup-To: poster
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Organization: MIT SIPB
Keywords: twiddler keyboard book

I just got a "Twiddler" one-handed keyboard+mouse (see Byte, March
1992, "First Impressions" article by Carol J. Swartz for details.) The
device has a keyboard connector and a 9-pin serial connector. It only
uses the former for power (I've verified this -- I've got the thing
running on a laptop with no keyboard port by stealing +5v from the
printer port :-) and thus does all communication through the serial
port. 
	The drivers they supply for DOS and Windows work fine, but I
usually use Linux and 386BSD on my PC hardware, so I figured I'd just
decipher the protocol and write my own drivers. However, that's
getting harder than it looked -- neither procomm nor kermit indicate
any activity on COM1. Kermit does seem to notice the device getting
set to 2400baud if I run the driver, but I get no data out of it. 
	My breakout box shows nothing (I suspect it's not getting
enough power to drive the LED's), and kermit claims that CD and the
other status lines are off. Any ideas about how it's feeding data? Any
recommendations of books on hardware-level programming for the PC
(BIOS calls aren't even vaguely useful, for most of my hacking the
BIOS is either not there or is what I'm trying to decipher :-)