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47 lines
868 B
ArmAsm
47 lines
868 B
ArmAsm
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; ***
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; CC65 Lynx Library
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;
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; Originally by Bastian Schick, BLL kit mikey.mac
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; http://www.geocities.com/SiliconValley/Byte/4242/lynx/
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;
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; Ported to cc65 (http://www.cc65.org) by
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; Shawn Jefferson, June 2004
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;
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; Ullrich von Bassewitz, 2004-10-09, small changes.
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;
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; void __fastcall__ lynx_change_framerate (unsigned char rate);
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; /* Change the framerate, in Hz. Recognized values are 50, 60 and 75. */
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;
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.include "lynx.inc"
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.export _lynx_change_framerate
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.code
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_lynx_change_framerate:
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cmp #75
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beq set_75
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cmp #60
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beq set_60
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cmp #50
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bne exit
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set_50: lda #$bd
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ldx #$31
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bra doit
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set_60: lda #$9e
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ldx #$29
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bra doit
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set_75: lda #$7e
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ldx #$20
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doit: sta HTIMBKUP
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stx PBKUP
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exit: rts
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