koreth%panarthea.ebay@sun.com (Steven Grimm) (09/17/89)
Submitted-by: dbrooks@osf.org (David Brooks) Posting-number: Volume 2, Issue 82 Archive-name: nolock ***************************************************************** * * * NOLOCK * * * * After this program is executed, the CapsLock key will have * * no effect, provided the keyboard translation table is set * * only by calls to Keytbl() and Bioskeys(). You can still set * * the tables by setting pointers into the vector whose address * * is returned by Keytbl(). * * * * Written for jas (Sozobon assembler). Thanks to Abacus's * * "Atari ST Internals" for insights. * * * * Copyright (c) 1989, David Brooks, All Rights Reserved. Use * * and distribute freely. * * * ***************************************************************** * * * Some constant definitions (trap codes mainly) * GEMDOS equ 1 BIOS equ 13 XBIOS equ 14 Keytbl equ 16 Bioskeys equ 24 Setexec equ 5 Keep equ $31 XBIOSV equ 46 XBIOSVAD equ $b8 sbit equ 13 * Supervisor status bit Magicnum equ $44424e4c * 'DBNL' must be just before trapad * * Program starts here. It's all one text section, as we need to * intermix code and data. The initialization is at the end, and * will be handed back to GEMDOS. * start: bra setup * * Static data: * transp: ds.l 1 * Will point to table ptr vector normp: ds.l 1 * Default non-shift table shiftp: ds.l 1 * Default shifted table trap14: ds.l 1 * Replaced xbios vector magic: dc.l Magicnum * * Here's the xbios trap * trapad: lea 6(a7),a0 * Point to args if in super mode btst #sbit,(a7) bne checkcodes dc.w $4e68 * move.l USP,a0 -- Point to args * if in user mode checkcodes: cmpi.w #Bioskeys,(a0) beq dobioskeys cmpi.w #Keytbl,(a0)+ beq dokeytbl move.l trap14,a0 * Go to standard trap handler jmp (a0) * * One of these routines for Bioskeys or Keytbl * dobioskeys: move.l transp,a1 * No args, no return. Just move.l normp,d0 * set the table to norm, shift, norm move.l d0,(a1)+ move.l shiftp,(a1)+ move.l d0,(a1) rte dokeytbl: move.l transp,d0 * Three args, returns address of vector move.l d0,a1 move.l (a0)+,d1 bmi nostd move.l d1,(a1) * put arg1 into standard and capslock move.l d1,8(a1) nostd: move.l (a0),d1 * put arg2 into shift bmi noshift move.l d1,4(a1) noshift: rte keeptop: * Top of kept memory * * Setup code. The stack will be at tpa, and can be somewhat abused. * 4(sp) points to the basepage. All of this can be done in user * mode. * setup: move.l 4(sp),a4 * * First we look for our magic number. * moveq.l #-1,d5 move.l d5,(sp) move.w #XBIOSV,-(sp) move.w #Setexec,-(sp) trap #BIOS * Setexec(46, -1L) move.l d0,a0 * Check current vector cmpi.l #Magicnum,-(a0) beq quickexit * Already installed * * Locate the original (actually, the current) key table vector and the two * interesting pointers. d5 has -1L (see above). * move.l d5,(sp) move.l d5,-(sp) move.l d5,-(sp) move.w #Keytbl,-(sp) * addr = Keytbl(-1L, -1L, -1L) trap #XBIOS move.l d0,transp * Save the vector pointer move.l d0,a0 move.l (a0)+,d1 * Save the normal table address move.l d1,normp move.l (a0)+,shiftp * Save the shift table address move.l d1,(a0) * Set capslock = normal * * Insinuate our code in the trap 14 vector * pea trapad move.w #XBIOSV,-(sp) move.w #Setexec,-(sp) trap #BIOS * Setexec(46, trapad) move.l d0,trap14 * Save old vector * * Exit, keeping the active code * lea keeptop,a0 sub.l a4,a0 * keeptop - basepage clr.w (sp) move.l a0,-(sp) move.w #Keep,-(sp) trap #GEMDOS * Keep(nbytes, 0) * * Come here if already installed for immediate exit * quickexit: clr.w (sp) trap #GEMDOS end