Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!asuvax!ncar!gatech!udel!haven!uflorida!reef.cis.ufl.edu!jdb From: jdb@reef.cis.ufl.edu (Brian K. W. Hook) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: NUMLOCK key and Extended Keyboard Scancodes .. HELP! Message-ID: <26602@uflorida.cis.ufl.EDU> Date: 31 Jan 91 13:49:58 GMT References: Sender: news@uflorida.cis.ufl.EDU Distribution: comp.sys.ibm.pc.hardware Organization: UF CIS Dept. Lines: 40 In article rfrost@spam.ua.oz.au (Richard Frost) writes: > >What scan codes do the extended keyboard keys output when the NUMLOCK >is 'ON' and when the NUMLOCK key is 'OFF' ? Are these different? > >If the scan codes are not different, how is it that it is possible to >get numerals output from the extended keys when the NUMLOCK status is >out of sequence with the computer by unplugging the keyboard? > >What good technical reference material is there on such topics? There are TONS of books on PC hardware programming! There are certain books I think just about every serious MS-DOS programmer will have at least one of: Advanced MS DOS Programming by Ray Duncan is one of them, PC Systems Programming by Abacus Publishing (this is pretty close to the ULTIMATE reference....has examples in C, ASM, BASIC, PASCAL, covers everything from video, TSRs, XMS, EMS, mouse, keyboard, graphics, etc. etc. PC Programmer's Source Book (?) by ? ...contains just about every chart imaginable MS-DOS Encyclopedia by Microsoft Press....gigantic compendium of information. Very good, thick, and expensive. And most importantly, THE book I could not survive without: Peter Norton's Programmer's Guide to the PC and PS/2 by Brady Books. This has just about everything covered, including reading the low BIOS area to determine if NUM LOCK is on or off, reading scan codes, reading ASCII codes, etc. etc. It doesn't cover mouse, but it gets real in depth about things such as DOS interrupts, BIOS interrupts, etc. etc. Hope this helps, Brian PS About the scan codes, I believe one of the subfunctions of the keyboard interrupt will return the ASCII code and scan code in the AX register.