CURSOR - POSITION in ASSEMBLER
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TOOL: 		Built-In ML-Monitor {Commodore C128}
Language: 	Assembler 
Extra:		Files are on floppy disk
Author: 	Misel Zivanovic
Note:		(C) 18th DEC 2025 - www.lived.ch, mzretro.ch
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Setting a cursor to a specific position isn't so difficult in BASIC.
And also not in assembler!

BASIC POSSIBILITIES!
	
	CHAR 1,10,0
	
	CHAR 1,10,0,"here i am"
		
	PRINTTAB(0-255)
	{This is going over few rows if the numbers are higher than 40}
	{e.g. a value of 200 is then 5th row}
	{e.g. a value of 220 is approximately middle of the screen, 5th row}	

	Poke 235,(rows, 0 - 24): Poke 236,(columns, 0 - 39)

	SYS 65520,rows {0 - 24},columns {0 - 39},0

	And finally, you could also use special CHR$ codes to place the cursor where you want!
	{check one of the Commodore C128 books for more info in regard to that}

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ASSEMBLER PART {ML-CODE}:

{as usually, copy/paste}


>00b00 a9 0a 85 eb a9 03 85 ec:I..KI..L
>00b08 a9 20 38 20 f0 ff a2 00:I 8 P.B.
>00b10 bd 29 0b 69 40 09 40 c9:.).I@.@I
>00b18 5a b0 09 20 d2 ff e8 e0:zP. R.H.
>00b20 1d d0 ed 60 a9 20 4c 1b:.PM.I l.
>00b28 0b 20 14 05 12 0d 09 0e:. ......
>00b30 01 14 0f 12 20 09 13 20:.... ..
>00b38 03 0f 0d 09 0e 07 20 06:...... .
>00b40 0f 12 20 19 0f 15 20 20:.. ...

NOTE: The message is here, so copy and paste this, not the code below!

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ALL EXPLAINED:

So, what do we have here:

. 00b00  a9 0a    lda #$0a	row #10
. 00b02  85 eb    sta $eb	write to register
. 00b04  a9 03    lda #$03	column
. 00b06  85 ec    sta $ec	write to register
. 00b08  a9 20    lda #$20	SPACE {empty}
. 00b0a  38       sec		set carry {needed to differ between SET {SEC} and READ {CLC} the cursor position}
. 00b0b  20 f0 ff jsr $fff0	Call the KERNAL routine
. 00b0e  a2 00    ldx #$00	counter to zero for our message
. 00b10  bd 29 0b lda $0b29,x	read the message
. 00b13  69 40    adc #$40	add 64 to counter {to get the right characters}
. 00b15  09 40    ora #$40	and invert {because carry is set! without this you would get reverse characters!}
. 00b17  c9 5a    cmp #$5a	get read of everything accept the characters {alphabet}
. 00b19  b0 09    bcs $0b24	replace it there with SPACE #$20, dec 32
. 00b1b  20 d2 ff jsr $ffd2	Bring it on the screen
. 00b1e  e8       inx		counter up
. 00b1f  e0 1d    cpx #$1d	message end?
. 00b21  d0 ed    bne $0b10     No? Repeat!
. 00b23  60       rts		Back to BASIC	
. 00b24  a9 20    lda #$20	Replacement for all but characters {alphabet}, SPACE inserted instead e.g. # = " "
. 00b26  4c 1b 0b jmp $0b1b

Message is not part of the code here!

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