CHECK THE KEYS $d4, dec 212 YOU WANT TO HAVE PRESSED TO CONTINUE WITH THE PROCESS!
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TOOL: 		Information {Commodore C128}
Language: 	None 
Extra:		none
Author: 	Misel Zivanovic
Note:		(C) 16th DEC 2025 - www.lived.ch, mzretro.ch
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lived.ch, 14:34 20.03.2024
update: 16.12.2025
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Commodore C128 address register >>> $d4, dec 212, Matrix Coordinate of Current Key Pressed
Commodore C64  address register >>> $cb, dec 203, Matrix Coordinate of Current Key Pressed

Decimal    Hex$		Decimal	   Hex$		Decimal    Hex$		Decimal	     	     Hex$

A = 10	   #$0a		O = 38 	   #$26		1 = 56     #$38		Up Arrow    = 83     #$53	
B = 28	   #$1c		P = 41	   #$29		2 = 59     #$3b		Down Arrow  = 84     #$54
C = 20	   #$14		Q = 62	   #$3e		3 = 08     #$08		Left Arrow  = 85     #$55
D = 18	   #$12		R = 17	   #$11		4 = 11     #$0b		Right Arrow = 86     #$56
E = 14	   #$0e		S = 13	   #$0d		5 = 16     #$10		
F = 21	   #$15		T = 22	   #$16		6 = 19     #$13		{Numeric Block}
G = 26	   #$1a		U = 30	   #$1e		7 = 24     #$18		Decimal    Hex$	     Decimal    Hex$
H = 29	   #$1d		V = 31	   #$1f		8 = 27     #$1b		1 = 71     $47	     6 = 77     #$4d
I = 33	   #$21		W = 09	   #$09		9 = 32     #$20		2 = 68     $44       7 = 70     #$46
J = 34	   #$22		X = 23	   #$17		0 = 35     #$23		3 = 79     $4f       8 = 65     #$41
K = 37	   #$25		Y = 25     #$19	    SPACE = 60     #$3c		4 = 69     $45       9 = 78     #$4e
L = 42	   #$2a		Z = 12     #$0c     ENTER = 01     #$01		5 = 66     $42       0 = 81     #$51
M = 36     #$24				    ESC	  = 72	   #$48	    ENTER = 76     $4c 	     - = 74	#$4a
N = 39     #$27										     + = 73	#$49

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{16.12.2025 - No idea why this are the results! Maybe because i use no real hardware?}

FUNKTION KEY:		F1		F3		F5		F7	
{direct, F1-F3-F5-F7}	04, #$04	05, #$05	06, #$06	3, #$03

FUNKTION KEY:		F2		F4		F6		F8 
{With SHIFT pressed}
Code for SHIFT		04		05		06		03					


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$d3, dec 211, Shift, Ctrl etc.	{ The values are cumulative; if both SHIFT and CONTROL are 	   }
Shift key status flag		{ pressed simultaneously, the value here will be 5 {4 + 1}    	   }
				{ Based on the value here, the SCNKEY routine chooses a keyboard   }
				{ table pointer value to be stored in 204-20S/$CC-$CD 		   }
				{ Note: Bit 7 of this location is also used as a flag to indicate  }
				{ when the extra characters read using the VIC chip lines are      }
				{ being scanned.						   } 

				Key 		Bit 	Bit value
				SHIFT 		0 	 1/$01
				Commodore 	1 	 2/$02
				CONTROL 	2 	 4/$04
				ALT 		3 	 8/$08
				CAPS LOCK 	4 	16/$10
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EXAMPLE 1: {endless loop until you press any key}

a 01300  a5 d4    lda $d4	Load the active code {default value is #$58, dec 88, if nothing is pressed}
a 01302  c9 58    cmp #$58	If it is #$58, dec 88
a 01304  f0 fa    beq $1300	Then we go back to check again until any key is pressed
a 01306  60       rts		When a key is pressed, return to subroutine or BASIC {If called from BASIC}


EXAMPLE 2: {ENDLESS LOOP until you press Q to exit and delete keyboard buffer}

. 01300  a5 d4    lda $d4
. 01302  c9 3e    cmp #$3e
. 01304  f0 02    beq $1308
. 01306  d0 f8    bne $1300
. 01308  a9 00    lda #$00
. 0130a  85 d0    sta $d0
. 0130c  60       rts

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ALTERNATIVE WAYS!

EXAMPLE 1: {Kernal GETIN routine $ffe4 to check if ENTER was pressed}

NOTE	 : This has nothing to do with KEYBOARD-MATRIX and $d4, dec 212!!!

. 01300  20 e4 ff jsr $ffe4
. 01303  c9 0d    cmp #$0d		{ASCII Code CHR$(13) or hex #$0d}. You work with the Character Codes!
. 01305  f0 03    beq $130a
. 01307  4c 00 13 jmp $1300
. 0130a  60       rts