ddj article and source code

The keyboard scan codes you see listed in Books and FAQs and so forth are NOT current for a MFII (101-key expanded) keyboard. The Linux source code does document all this.

Typical data transfer speed from the keyboard  is approx. 8kHz . The clock pulses are 60 or 70 uS long so 120uS for the period.

see also:

• Articles about XT and AT type keyboards can be found in April/May 1995 issues of Circuit Cellar Ink.
• An early copy of Micro Cornucopia ( March-April 1990 ) has the details about standards, interface chips etc
• John Voth has keyboard interfacing information at: http://nyquist.ee.ualberta.ca/~jdv/
• http://www.enterprise.ca/~jbilous/kybrd03.htm
• http://www.barcodeman.com/scan_doc.html
• http://www.senet.com.au/~cpeacock for details on how to interface an AT keyboard to a system expecting ascii input.
• A PC Keyboard FAQ has been written by Mark Schultz. Send e-mail to mchultz@wctc.net for details.
• Go to the Aminet site (eg. ftp.netnet.net) and go to hard/hack, there you'll find 2 or more files for PC keyboard interfaces to Amiga. There is some documentation for the AT keyboard protocol.
• Check out the Philips site. There is supposed to be an app note for PC keyboard to serial format.
• http://boole.stanford.edu/~gdefouw/kbd/pic.html (PIC 16C84 Keyboard Transmit Routine)
• http://ourworld.compuserve.com/homepages/steve_lawther/keybinfo.htm keyboard to LCD display keyboard code viewer, with diagram etc.
• http://www.arne.si/~mauricio/PIC.HTM (not responding today)
• http://www.repairfaq.org/filipg/LINK/PORTS/F_Keyboard_FAQ.html
• http://members.tripod.com/~ilkerf/c64tower/F_Keyboard_FAQ.html is Yet Another Keyboard FAQ.
• http://www.geocities.com/SiliconValley/Bay/8302/keybrd.htm
• http://www.brouhaha.com/~eric/pic/
• http://www.hth.com/filelibrary/TXTFILES/keyboard.txt
• http://www-dept.cs.ucl.ac.uk/staff/B.Rosenberg/kbd/chord.html Interesting Chord Keyboards summary:
• http://www.atmel.com/atmel/acrobat/doc1235.pdf has C code for interfacing an AVR processor to a keyboard.
• http://www.hut.fi/Misc/Electronics/hwprojects.html#pc_keyboard, good PC hardware projects
• Hagstrom Electronics, 2 Green Lantern Boulevard Endicott, New York 13760, 1-888-690-9080 9x9 and 12x12 matrix to PC or RS232 encoder boards
• http://www.usar.com/prodnser/keycod.htm
• http://junitec.ist.utl.pt/einfo/hwprojects.html#pc_keyboard
• http://www.freebsd.org/~fsmp/HomeAuto/Focus.html
• Ken's Gameboy and PIC Projects Page
• http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/keyboard/keyboard.html