********************************************************************
* KeyDrv - Keyboard Driver for CoCo 3
*
* $Id$
*
* Edt/Rev  YYYY/MM/DD  Modified by
* Comment
* ------------------------------------------------------------------
*   4      1998/10/10  Robert Gault
* L2 Upgrade distribution version with annotations by Robert Gault.

         nam   KeyDrv    
         ttl   Keyboard Driver for CoCo 3

* Disassembled 98/09/09 09:02:10 by Disasm v1.6 (C) 1988 by RML

         ifp1            
         use   defsfile
         use   cocovtio.d
         ENDC            

tylg     set   Systm+Objct
atrv     set   ReEnt+rev 
rev      set   $00       
edition  equ   4         

         mod   eom,name,tylg,atrv,entry,size
size     equ   .         

name     fcs   /KeyDrv/  
         fcb   edition   

entry    equ   *         

* Init - Initialize keyboard
         lbra  Init      

* Term - Terminate keyboard
         lbra  Term      

* Function - Test for function keys
         lbra  FuncKeys  

* Read - read keys if pressed
* Exit: A = key pressed
ReadKys  ldu   <D.CCMem		Get VTIO global memory into U
         ldx   #PIA0Base	base address of PIA #0
         ldb   #$FF
         stb   $02,x		clear all row strobes
         ldb   ,x		read Joystick buttons
         comb			invert bits so 1=pressed
         andb  #%00001111	keep only buttons
         bne   L0059		branch if button pushed; error routine
         clr   $02,x		enable all strobe lines
         lda   ,x		read PIA #0
         coma            
* Check to see if ANY key is down
         anda  #%01111111	mask only the joystick comparator
         beq   NoKey		branch if no keys pressed
* Here, a key is down on the keyboard
         pshs  dp		save our DP
         tfr   u,d		move statics ptr to D
         tfr   a,dp		set DP to the address in regU
         bsr   EvalMatrix	evaluate the found key matrix
         puls  dp		return to system DP
         bpl   L005B		valid key
NoKey    clra			regA    would have been the found key
         ldb   <G.CapLok,u	CapsLock/SysRq key down flag
         bne   L0056		branch if down
         clr   <G.KTblLC,u	Key table entry# last checked (1-3)
         IFNE  H6309
         comd
         ELSE
         coma
         comb
         ENDC
         sta   <G.LKeyCd,u	last keyboard code
         sta   <G.2Key1,u	2nd key table storage; $FF=none
         std   <G.2Key2,u	format (Row/Column)
L0056    clr   <G.CapLok,u	see above
L0059    ldb   #$FF      
L005B    rts             


* Evaluates the keyboard matrix for a key
EvalMatrix
         ldx   #PIA0Base	base value of PIA #0
         IFNE  H6309
         clrd            
         ELSE
         clra            
         clrb            
         ENDC
         std   <G.ShftDn	shift/CTRL flag; 0=NO $FF=YES
         std   <G.KeyFlg	PIA bits/ALT flag
*	%00000111-Column # (Output, 0-7)
*	%00111000-Row # (Input, 0-6)
         IFNE  H6309     
         comd			set D to $FFFF
         ELSE            
         coma            
         comb			set primary key table
         ENDC            
         std   <G.Key1		key 1&2 flags $FF=none
         sta   <G.Key3		key 3     "
         deca			ie. lda #%11111110
         sta   $02,x		strobe one column
L006E    lda   ,x		read PIA #0 row states
         coma			invert bits so 1=key pressed
         anda  #$7F		keep only keys, bit 0=off 1=on
         beq   L0082		no keys pressed, try next column
         ldb   #$FF		preset counter to -1
L0077    incb            
         lsra			bit test regA
         bcc   L007E		no key so branch
         lbsr  L010E		convert column/row to matrix value and store it
L007E    cmpb  #$06		max counter
         blo   L0077		loop if more bits to test
L0082    inc   <G.KeyFlg	counter; used here for column
         orcc  #Carry		bit marker; disable strobe
         rol   $02,x		shift to next column
         bcs   L006E		not finished with columns so loop
         lbsr  L0166		simultaneous check; recover key matrix value
         bmi   L00F5		invalid so go
         cmpa  <G.LKeyCd	last keyboard code	
         bne   L0095     
         inc   <G.KySame	same key flag ?counter?
L0095    sta   <G.LKeyCd	setup for last key pressed
         beq   L00B5		if @ key, use lookup table
         suba  #$1A		the key value (matrix) of Z
         bhi   L00B5		not a letter so go
         adda  #$1A		restore regA
         ldb   <G.CntlDn	CTRL flag
         bne   L00E0		CTRL is down so go
         adda  #$40		convert to ASCII value; all caps
         ldb   <G.ShftDn	shift key flag
         ldy   <G.CurDev	get current device static memory pointer
         eorb  <V.ULCase,y	caps lock and keyboard mouse flags
         andb  #CapsLck		test caps flag
         bne   L00E0		not shifted so go
         adda  #$20		convert to ASCII lower case
         bra   L00E0     
* not a letter key, use the special keycode lookup table at L01DC.
* Entry: regA = table index (matrix scancode-26)
L00B5    ldb   #$03		three entries per key (normal,shift,ctrl)
         mul			convert index to table offset
         lda   <G.ShftDn	shift key flag
         beq   L00BF		not shifted so go
         incb			adjust offset for SHIFTed entry
         bra   L00C5     
L00BF    lda   <G.CntlDn	CTRL flag
         beq   L00C5		adjust offset for CONTROL entry
         addb  #$02      
L00C5    ldx   <G.CurDev	point X to device's static memory
         lda   <V.KySnsFlg,x	key sense flag
         beq   L00D0		not set so go
         cmpb  #$11		spacebar
         ble   L00F3		must be an arrow so go
L00D0    cmpb  #$4B		ALT key? (was cmpb #$4C)
         blt   L00D8		not ALT, CTRL, F1, F2, or SHIFT so go
         inc   <G.AltDwn	flag special keys (ALT,CTRL)
         subb  #$06		and adjust offset to skip them
L00D8    leax  >L01DC,pcr	decode table
         lda   b,x       
         bmi   L00F6		if regA = $81 - $84, special key
* several entries to this routine from any key press; regA is already ASCII
L00E0    ldb   <G.AltDwn	was ALT flagged?
         beq   L00F0		no so go
         cmpa  #$3F		?	
         bls   L00EE		# or code
         cmpa  #$5B		[
         bhs   L00EE		capital letter so go
         ora   #$20		convert to lower case
L00EE    ora   #$80		set for ALT characters
L00F0    andcc  #^Negative	not negative
         rts             
L00F3    orcc  #Negative	set negative
L00F5    rts             
* Flag that a special key was hit
L00F6    inc   <G.CapLok	caps lock/SysRq
         inc   <G.Clear		one shot caps lock/SysRq
         bra   L00F0     
* Calculate arrow keys for key sense byte
L00FC    pshs  b,a		convert column into power of 2
         clrb            
         orcc  #Carry    
         inca            
L0102    rolb            
         deca            
         bne   L0102     
*         bra   L0108      WHY IS THIS HERE??
L0108    orb   <G.KySns		previous value of column
         stb   <G.KySns  
         puls  pc,b,a    
* Check special keys (Shift, Cntrl, Alt)
L010E    pshs  b,a       
         cmpb  #$03		is it row 3?
         bne   L011C     
         lda   <G.KeyFlg	get column #
         cmpa  #$03		is it column 3?; ie up arrow
         blt   L011C		if lt must be a letter
         bsr   L00FC		its a non letter so bsr
L011C    lslb			B*8  8 keys per row
         lslb            
         lslb            
         addb  <G.KeyFlg	add in the column #
         cmpb  #$33		ALT
         bne   L012B     
         inc   <G.AltDwn	ALT down flag
         ldb   #$04      
         bra   L0108     
L012B    cmpb  #$34		CTRL
         bne   L0135     
         inc   <G.CntlDn	CTRL down flag
         ldb   #$02      
         bra   L0108     
L0135    cmpb  #$37		SHIFT key
         bne   L013F     
         com   <G.ShftDn	SHIFT down flag
         ldb   #$01      
         bra   L0108     
* check how many key (1-3) are currently being pressed
L013F    pshs  x         
         leax  <$2D,u		1st key table
         bsr   L014A     
         puls  x         
         puls  pc,b,a    
L014A    pshs  a         
         lda   ,x        
         bpl   L0156     
         stb   ,x        
         ldb   #$01      
         puls  pc,a      
L0156    lda   $01,x     
         bpl   L0160     
         stb   $01,x     
         ldb   #$02      
         puls  pc,a      
L0160    stb   $02,x     
         ldb   #$03      
         puls  pc,a      
* simultaneous key test
L0166    pshs  y,x,b     
         ldb   <G.KTblLC	key table entry #
         beq   L019D     
         leax  <$2A,u		point to 2nd key table
         pshs  b         
L0171    leay  <$2D,u		1st key table
         ldb   #$03      
         lda   ,x		get key #1
         bmi   L018F		go if invalid? (no key)
L017A    cmpa  ,y		is it a match?
         bne   L0184		go if not a matched key
         clr   ,y        
         com   ,y		set value to $FF
         bra   L018F     
L0184    leay  $01,y     
         decb            
         bne   L017A     
         lda   #$FF      
         sta   ,x        
         dec   <G.KTblLC	key table entry#
L018F    leax  $01,x     
         dec   ,s		column counter
         bne   L0171     
         leas  $01,s     
         ldb   <G.KTblLC	key table entry (can test for 3 simul keys)
         beq   L019D     
         bsr   L01C4     
L019D    leax  <$2D,u		1st key table
         lda   #$03      
L01A2    ldb   ,x+       
         bpl   L01B5     
         deca            
         bne   L01A2     
         ldb   <G.KTblLC	key table entry (can test for 3 simul keys)
         beq   L01C0     
         decb            
         leax  <$2A,u		2nd key table
         lda   b,x       
         bra   L01BE     
L01B5    tfr   b,a       
         leax  <$2A,u		2nd key table
         bsr   L014A     
         stb   <G.KTblLC 
L01BE    puls  pc,y,x,b  
L01C0    orcc  #Negative	flag negative
         puls  pc,y,x,b  
* Sort 3 byte packet @ G.2Key1 according to sign of each byte
* so that positive #'s are at beginning & negative #'s at end
L01C4    leax  <$2A,u		2nd key table
         bsr   L01CF		sort bytes 1 & 2
         leax  $01,x     
         bsr   L01CF		sort bytes 2 & 3
         leax  -$01,x		sort 1 & 2 again (fall thru for third pass)
L01CF    ldb   ,x		get current byte
         bpl   L01DB		positive - no swap
         lda   $01,x		get next byte
         bmi   L01DB		negative - no swap
         std   ,x		swap the bytes
L01DB    rts             

* Special Key Codes Table : 3 entries per key - Normal, Shift, Control
* They are in COCO keyboard scan matrix order; the alphabetic and meta
* control keys are handled elsewhere.  See INSIDE OS9 LEVEL II p.4-1-7
L01DC    fcb   $40,$60,$00   '@,'`,null				
	 fcb   $0c,$1c,$13   UP ARROW:    FF, FS,DC3
	 fcb   $0a,$1a,$12   DOWN ARROW:  LF,SUB,DC2
	 fcb   $08,$18,$10   LEFT ARROW:  BS,CAN,DLE
	 fcb   $09,$19,$11   RIGHT ARROW: HT, EM,DC1
	 fcb   $20,$20,$20   SPACEBAR
	 fcb   $30,$30,$81   '0,'0,$81 (caps lock toggle)
	 fcb   $31,$21,$7c   '1,'!,'|
	 fcb   $32,$22,$00   '2,'",null
	 fcb   $33,$23,$7e   '3,'#,'~
	 fcb   $34,$24,$1d   '4,'$,GS (was null)
	 fcb   $35,$25,$1e   '5,'%,RS (was null)
	 fcb   $36,$26,$1f   '6,'&,US (was null)
	 fcb   $37,$27,$5e   '7,'','^
	 fcb   $38,$28,$5b   '8,'(,'[
	 fcb   $39,$29,$5d   '9,'),']
	 fcb   $3a,$2a,$00   ':,'*,null
	 fcb   $3b,$2b,$7f   ';,'+,DEL
	 fcb   $2c,$3c,$7b   ',,'<,'{
	 fcb   $2d,$3d,$5f   '-,'=,'_
	 fcb   $2e,$3e,$7d   '.,'>,'}
	 fcb   $2f,$3f,$5c   '/,'?,'\
	 fcb   $0d,$0d,$0d   ENTER key					
	 fcb   $82,$83,$84   CLEAR key (NextWin, PrevWin, KbdMouse toggle)
	 fcb   $05,$03,$1b   BREAK key (ENQ,ETX,ESC)
	 fcb   $31,$33,$35   F1 key (converts to $B1,$B3,$B5)
	 fcb   $32,$34,$36   F2 key (converts to $B2,$B4,$B6)

*L01DC    fdb   $4060,$000c,$1c13,$0a1a,$1208,$1810,$0919,$1120
*         fdb   $2020,$3030,$8131,$217c,$3222,$0033,$237e,$3424
*         fdb   $0035,$2500,$3626,$0037,$275e,$3828,$5b39,$295d
*         fdb   $3a2a,$003b,$2b7f,$2c3c,$7b2d,$3d5f,$2e3e,$7d2f
*         fdb   $3f5c,$0d0d,$0d82,$8384,$0503,$1b31,$3335,$3234
*         fcb   $36       

* Init and Term do nothing for this CoCo keyboard subroutine module
Init                     
Term     clrb            
         rts             

* This entry point tests for the F1/F2 function keys on a CoCo 3
* keyboard.
* Exit: A = Function keys pressed (Bit 0 = F1, Bit 2 = F2)
FuncKeys ldu   <D.CCMem		get VTIO global mem pointer into U
         ldx   #PIA0Base	get address of PIA #0
         clra			clear A
         ldb   #%11011111	strobe column #6 of PIA #0
         stb   $02,x     
         IFNE  H6309
         tim   #%01000000,0,x	F1 down?
         ELSE
         ldb   ,x		read PIA #0
         bitb  #%01000000	test for F1 function key
         ENDC
         bne   CheckF2		branch if set (key not down)
         inca			flag F1 as down
CheckF2  ldb   #%10111111	strobe column #7 PIA #0
         stb   $02,x     
         IFNE  H6309
         tim   #%01000000,0,x	F2 down?
         ELSE
         ldb   ,x		read PIA #0
         bitb  #%01000000	test for F2 function key
         ENDC
         bne   L024C     
         ora   #$04		flag F2 as down
L024C    rts             

         emod
eom      equ   *
         end