int9.asm

汇编编程艺术

; INT9.ASM
;
; A short TSR to provide a driver for the keyboard hardware interrupt.
;
; Note that this code does not patch into int 2Fh (multiplex interrupt)
; nor can you remove this code from memory except by rebooting.
; If you want to be able to do these two things (as well as check for
; a previous installation), see the chapter on resident programs.  Such
; code was omitted from this program because of length constraints.
;
;
; cseg and EndResident must occur before the standard library segments!

cseg		segment	para public 'code'
OldInt9		dword	?
cseg		ends

; Marker segment, to find the end of the resident section.

EndResident	segment	para public 'Resident'
EndResident	ends

		.xlist
		include 	stdlib.a
		includelib	stdlib.lib
		.list


NumLockScan	equ	45h
ScrlLockScan	equ	46h
CapsLockScan	equ	3ah
CtrlScan	equ	1dh
AltScan		equ	38h
RShiftScan	equ	36h
LShiftScan	equ	2ah
InsScanCode	equ	52h
DelScanCode	equ	53h

; Bits for the various modifier keys

RShfBit		equ	1
LShfBit		equ	2
CtrlBit		equ	4
AltBit		equ	8
SLBit		equ	10h
NLBit		equ	20h
CLBit		equ	40h
InsBit		equ	80h


KbdFlags	equ	<byte ptr ds:[17h]>
KbdFlags2	equ	<byte ptr ds:[18h]>
KbdFlags3	equ	<byte ptr ds:[96h]>
KbdFlags4	equ	<byte ptr ds:[97h]>

byp		equ	<byte ptr>


cseg		segment	para public 'code'
		assume	ds:nothing

; Scan code translation table.
; The incoming scan code from the keyboard selects a row.
; The modifier status selects the column.
; The word at the intersection of the two is the scan/ASCII code to
; put into the PC's type ahead buffer.
; If the value fetched from the table is zero, then we do not put the
; character into the type ahead buffer.
;
;		norm   shft   ctrl   alt    num    caps   shcap  shnum

ScanXlat word	0000h, 0000h, 0000h, 0000h, 0000h, 0000h, 0000h, 0000h
	word	011bh, 011bh, 011bh, 011bh, 011bh, 011bh, 011bh, 011bh	;ESC
	word	0231h, 0231h, 0000h, 7800h, 0231h, 0231h, 0231h, 0321h	;1 !
	word	0332h, 0340h, 0300h, 7900h, 0332h, 0332h, 0332h, 0332h	;2 @
	word	0433h, 0423h, 0000h, 7a00h, 0433h, 0433h, 0423h, 0423h	;3 #
	word	0534h, 0524h, 0000h, 7b00h, 0534h, 0534h, 0524h, 0524h	;4 $
	word	0635h, 0625h, 0000h, 7c00h, 0635h, 0635h, 0625h, 0625h	;5 %
	word	0736h, 075eh, 071eh, 7d00h, 0736h, 0736h, 075eh, 075eh	;6 ^

	word	0837h, 0826h, 0000h, 7e00h, 0837h, 0837h, 0826h, 0826h	;7 &
	word	0938h, 092ah, 0000h, 7f00h, 0938h, 0938h, 092ah, 092ah	;8 *
	word	0a39h, 0a28h, 0000h, 8000h, 0a39h, 0a39h, 0a28h, 0a28h	;9 (
	word    0b30h, 0b29h, 0000h, 8100h, 0b30h, 0b30h, 0b29h, 0b29h	;0 )
	word	0c2dh, 0c5fh, 0000h, 8200h, 0c2dh, 0c2dh, 0c5fh, 0c5fh	;- _
	word	0d3dh, 0d2bh, 0000h, 8300h, 0d3dh, 0d3dh, 0d2bh, 0d2bh	;= +
	word	0e08h, 0e08h, 0e7fh, 0000h, 0e08h, 0e08h, 0e08h, 0e08h	;bksp
	word	0f09h, 0f00h, 0000h, 0000h, 0f09h, 0f09h, 0f00h, 0f00h	;Tab

;		norm   shft   ctrl   alt    num    caps   shcap  shnum
	word	1071h, 1051h, 1011h, 1000h, 1071h, 1051h, 1051h, 1071h	;Q
	word	1177h, 1057h, 1017h, 1100h, 1077h, 1057h, 1057h, 1077h	;W
	word	1265h, 1245h, 1205h, 1200h, 1265h, 1245h, 1245h, 1265h	;E
	word	1372h, 1352h, 1312h, 1300h, 1272h, 1252h, 1252h, 1272h	;R
	word	1474h, 1454h, 1414h, 1400h, 1474h, 1454h, 1454h, 1474h	;T
	word	1579h, 1559h, 1519h, 1500h, 1579h, 1559h, 1579h, 1559h	;Y
	word	1675h, 1655h, 1615h, 1600h, 1675h, 1655h, 1675h, 1655h	;U
	word	1769h, 1749h, 1709h, 1700h, 1769h, 1749h, 1769h, 1749h	;I

	word	186fh, 184fh, 180fh, 1800h, 186fh, 184fh, 186fh, 184fh	;O
	word	1970h, 1950h, 1910h, 1900h, 1970h, 1950h, 1970h, 1950h	;P
	word	1a5bh, 1a7bh, 1a1bh, 0000h, 1a5bh, 1a5bh, 1a7bh, 1a7bh	;[ {
	word	1b5dh, 1b7dh, 1b1dh, 0000h, 1b5dh, 1b5dh, 1b7dh, 1b7dh	;] }
	word	1c0dh, 1c0dh, 1c0ah, 0000h, 1c0dh, 1c0dh, 1c0ah, 1c0ah	;enter
	word	1d00h, 1d00h, 1d00h, 1d00h, 1d00h, 1d00h, 1d00h, 1d00h	;ctrl
	word	1e61h, 1e41h, 1e01h, 1e00h, 1e61h, 1e41h, 1e61h, 1e41h	;A
	word	1f73h, 1f5eh, 1f13h, 1f00h, 1f73h, 1f53h, 1f73h, 1f53h	;S

;		norm   shft   ctrl   alt    num    caps   shcap  shnum
	word	2064h, 2044h, 2004h, 2000h, 2064h, 2044h, 2064h, 2044h	;D
	word	2166h, 2146h, 2106h, 2100h, 2166h, 2146h, 2166h, 2146h	;F
	word	2267h, 2247h, 2207h, 2200h, 2267h, 2247h, 2267h, 2247h	;G
	word	2368h, 2348h, 2308h, 2300h, 2368h, 2348h, 2368h, 2348h	;H
	word	246ah, 244ah, 240ah, 2400h, 246ah, 244ah, 246ah, 244ah	;J
	word	256bh, 254bh, 250bh, 2500h, 256bh, 254bh, 256bh, 254bh	;K
	word	266ch, 264ch, 260ch, 2600h, 266ch, 264ch, 266ch, 264ch	;L
	word	273bh, 273ah, 0000h, 0000h, 273bh, 273bh, 273ah, 273ah	;; :

	word	2827h, 2822h, 0000h, 0000h, 2827h, 2827h, 2822h, 2822h	;' "
	word	2960h, 297eh, 0000h, 0000h, 2960h, 2960h, 297eh, 297eh	;` ~
	word	2a00h, 2a00h, 2a00h, 2a00h, 2a00h, 2a00h, 2a00h, 2a00h	;LShf
	word	2b5ch, 2b7ch, 2b1ch, 0000h, 2b5ch, 2b5ch, 2b7ch, 2b7ch	;\ |
	word	2c7ah, 2c5ah, 2c1ah, 2c00h, 2c7ah, 2c5ah, 2c7ah, 2c5ah	;Z
	word	2d78h, 2d58h, 2d18h, 2d00h, 2d78h, 2d58h, 2d78h, 2d58h	;X
	word	2e63h, 2e43h, 2e03h, 2e00h, 2e63h, 2e43h, 2e63h, 2e43h	;C
	word	2f76h, 2f56h, 2f16h, 2f00h, 2f76h, 2f56h, 2f76h, 2f56h	;V

;		norm   shft   ctrl   alt    num    caps   shcap  shnum
	word	3062h, 3042h, 3002h, 3000h, 3062h, 3042h, 3062h, 3042h	;B
	word	316eh, 314eh, 310eh, 3100h, 316eh, 314eh, 316eh, 314eh	;N
	word	326dh, 324dh, 320dh, 3200h, 326dh, 324dh, 326dh, 324dh	;M
	word	332ch, 333ch, 0000h, 0000h, 332ch, 332ch, 333ch, 333ch	;, <
	word	342eh, 343eh, 0000h, 0000h, 342eh, 342eh, 343eh, 343eh	;. >
	word	352fh, 353fh, 0000h, 0000h, 352fh, 352fh, 353fh, 353fh	;/ ?
	word	3600h, 3600h, 3600h, 3600h, 3600h, 3600h, 3600h, 3600h	;rshf
	word	372ah, 0000h, 3710h, 0000h, 372ah, 372ah, 0000h, 0000h	;* PS

	word	3800h, 3800h, 3800h, 3800h, 3800h, 3800h, 3800h, 3800h	;alt
	word	3920h, 3920h, 3920h, 0000h, 3920h, 3920h, 3920h, 3920h	;spc
	word	3a00h, 3a00h, 3a00h, 3a00h, 3a00h, 3a00h, 3a00h, 3a00h	;caps
	word	3b00h, 5400h, 5e00h, 6800h, 3b00h, 3b00h, 5400h, 5400h	;F1
	word	3c00h, 5500h, 5f00h, 6900h, 3c00h, 3c00h, 5500h, 5500h	;F2
	word	3d00h, 5600h, 6000h, 6a00h, 3d00h, 3d00h, 5600h, 5600h	;F3
	word	3e00h, 5700h, 6100h, 6b00h, 3e00h, 3e00h, 5700h, 5700h	;F4
	word	3f00h, 5800h, 6200h, 6c00h, 3f00h, 3f00h, 5800h, 5800h	;F5

;		norm   shft   ctrl   alt    num    caps   shcap  shnum
	word	4000h, 5900h, 6300h, 6d00h, 4000h, 4000h, 5900h, 5900h	;F6
	word	4100h, 5a00h, 6400h, 6e00h, 4100h, 4100h, 5a00h, 5a00h	;F7
	word	4200h, 5b00h, 6500h, 6f00h, 4200h, 4200h, 5b00h, 5b00h	;F8
	word	4300h, 5c00h, 6600h, 7000h, 4300h, 4300h, 5c00h, 5c00h	;F9
	word	4400h, 5d00h, 6700h, 7100h, 4400h, 4400h, 5d00h, 5d00h	;F10
	word	4500h, 4500h, 4500h, 4500h, 4500h, 4500h, 4500h, 4500h	;num
	word	4600h, 4600h, 4600h, 4600h, 4600h, 4600h, 4600h, 4600h	;scrl
	word	4700h, 4737h, 7700h, 0000h, 4737h, 4700h, 4737h, 4700h	;home

	word	4800h, 4838h, 0000h, 0000h, 4838h, 4800h, 4838h, 4800h	;up
	word	4900h, 4939h, 8400h, 0000h, 4939h, 4900h, 4939h, 4900h	;pgup
	word	4a2dh, 4a2dh, 0000h, 0000h, 4a2dh, 4a2dh, 4a2dh, 4a2dh	;-
	word	4b00h, 4b34h, 7300h, 0000h, 4b34h, 4b00h, 4b34h, 4b00h	;left
	word	4c00h, 4c35h, 0000h, 0000h, 4c35h, 4c00h, 4c35h, 4c00h	;Cen
	word	4d00h, 4d36h, 7400h, 0000h, 4d36h, 4d00h, 4d36h, 4d00h	;right
	word	4e2bh, 4e2bh, 0000h, 0000h, 4e2bh, 4e2bh, 4e2bh, 4e2bh	;+
	word	4f00h, 4f31h, 7500h, 0000h, 4f31h, 4f00h, 4f31h, 4f00h	;end

;		norm   shft   ctrl   alt    num    caps   shcap  shnum
	word	5000h, 5032h, 0000h, 0000h, 5032h, 5000h, 5032h, 5000h	;down
	word	5100h, 5133h, 7600h, 0000h, 5133h, 5100h, 5133h, 5100h	;pgdn
	word	5200h, 5230h, 0000h, 0000h, 5230h, 5200h, 5230h, 5200h	;ins
	word	5300h, 532eh, 0000h, 0000h, 532eh, 5300h, 532eh, 5300h	;del
	word	0,0,0,0,0,0,0,0						; --
	word	0,0,0,0,0,0,0,0						; --
	word	0,0,0,0,0,0,0,0						; --
	word	5700h, 0000h, 0000h, 0000h, 5700h, 5700h, 0000h, 0000h	;F11

	word	5800h, 0000h, 0000h, 0000h, 5800h, 5800h, 0000h, 0000h	;F12



;****************************************************************************
;
; AL contains keyboard scan code.

PutInBuffer     proc    near
		push    ds
		push    bx

		mov     bx, 40h                 ;Point ES at the BIOS
		mov     ds, bx                  ; variables.

; If the current scan code is E0 or E1, we need to take note of this fact
; so that we can properly process cursor keys.

		cmp	al, 0e0h
		jne	TryE1
		or	KbdFlags3, 10b		;Set E0 flag
		and	KbdFlags3, 0FEh		;Clear E1 flag
		jmp	Done

TryE1:		cmp	al, 0e1h
		jne	DoScan
		or	KbdFlags3, 1		;Set E1 flag
		and	KbdFlags3, 0FDh		;Clear E0 Flag
		jmp	Done


; Before doing anything else, see if this is Ctrl-Alt-Del:

DoScan:		cmp	al, DelScanCode		;5300h
		jnz	TryIns
		mov	bl, KbdFlags
		and	bl, AltBit or CtrlBit	;Alt = bit 3, ctrl = bit 2
		cmp	bl, AltBit or CtrlBit
		jne	DoPIB
		mov	word ptr ds:[72h], 1234h	;Warm boot flag.
		jmp	dword ptr cs:RebootAdrs		;REBOOT Computer

RebootAdrs	dd	0ffff0000h			;Reset address.


; Check for the INS key here.  This one needs to toggle the ins bit
; in the keyboard flags variables.

TryIns:		cmp	al, InsScanCode
		jne	TryInsUp
		or	KbdFlags2, InsBit		;Note INS is down.
		jmp     doPIB				;Pass on INS key.

TryInsUp:	cmp	al, InsScanCode+80h		;INS up scan code.
		jne	TryLShiftDn
		and	KbdFlags2, not InsBit 		;Note INS is up.
		xor	KbdFlags, InsBit		;Toggle INS bit.
		jmp	QuitPIB

; Handle the left and right shift keys down here.

TryLShiftDn:	cmp	al, LShiftScan
		jne	TryLShiftUp
		or	KbdFlags, LShfBit		;Note that the left
		jmp	QuitPIB				; shift key is down.

TryLShiftUp:	cmp	al, LShiftScan+80h
		jne	TryRShiftDn
		and	KbdFlags, not LShfBit		;Note that the left
		jmp	QuitPIB				; shift key is up.


TryRShiftDn:	cmp	al, RShiftScan
		jne	TryRShiftUp
		or	KbdFlags, RShfBit		;Right shf is down.
		jmp	QuitPIB

TryRShiftUp:	cmp	al, RShiftScan+80h
		jne	TryAltDn
		and	KbdFlags, not RShfBit  		;Right shf is up.
		jmp	QuitPIB

; Handle the ALT key down here.

TryAltDn:	cmp	al, AltScan
		jne	TryAltUp
		or	KbdFlags, AltBit			;Alt key is down.
GotoQPIB:	jmp	QuitPIB

TryAltUp:	cmp	al, AltScan+80h
		jne	TryCtrlDn
		and	KbdFlags, not AltBit		;Alt key is up.
		jmp	DoPIB


; Deal with the control key down here.

TryCtrlDn:	cmp	al, CtrlScan
		jne	TryCtrlUp
		or	KbdFlags, CtrlBit		;Ctrl key is down.
		jmp	QuitPIB

TryCtrlUp:	cmp	al, CtrlScan+80h
		jne	TryCapsDn
		and	KbdFlags, not CtrlBit		;Ctrl key is up.
		jmp	QuitPIB

; Deal with the CapsLock key down here.

TryCapsDn:	cmp	al, CapsLockScan
		jne	TryCapsUp
		or	KbdFlags2, CLBit		;Capslock is down.
		xor	KbdFlags, CLBit			;Toggle capslock mode.
		jmp	QuitPIB

TryCapsUp:	cmp	al, CapsLockScan+80h
		jne	TrySLDn
		and	KbdFlags2, not CLBit		;Capslock is up.
		call	SetLEDs
		jmp	QuitPIB

; Deal with the Scroll Lock key down here.

TrySLDn:	cmp	al, ScrlLockScan
		jne	TrySLUp
		or	KbdFlags2, SLBit		;Scrl lock is down.
		xor	KbdFlags, SLBit			;Toggle scrl lock.
		jmp	QuitPIB

TrySLUp:	cmp	al, ScrlLockScan+80h
		jne	TryNLDn
		and	KbdFlags2, not SLBit		;Scrl lock is up.
		call	SetLEDs
		jmp	QuitPIB

; Handle the NumLock key down here.


TryNLDn:       	cmp	al, NumLockScan
		jne	TryNLUp
		or	KbdFlags2, NLBit		;Numlock is down.
		xor	KbdFlags, NLBit			;Toggle numlock.
		jmp	QuitPIB

TryNLUp:	cmp	al, NumLockScan+80h
		jne     DoPIB
		and	KbdFlags2, not NLBit		;Numlock is up.
		call	SetLEDs
		jmp	QuitPIB



; Handle all the other keys here:

DoPIB:		test	al, 80h			;Ignore all other up keys.
		jnz	QuitPIB