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AmigActive 10
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AACD 10.iso
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machine
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tp84.c
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C/C++ Source or Header
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2000-04-04
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992b
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44 lines
/***************************************************************************
machine.c
Functions to emulate general aspects of the machine (RAM, ROM, interrupts,
I/O ports)
***************************************************************************/
#include "driver.h"
#include "cpu/m6809/m6809.h"
extern unsigned char *tp84_sharedram; /* JB 970829 */
/* JB 970829 - just give it what it wants
F104: LDX $6400
F107: LDU $6402
F10A: LDA $640B
F10D: BEQ $F13B
F13B: LDX $6404
F13E: LDU $6406
F141: LDA $640C
F144: BEQ $F171
F171: LDA $2000 ; read beam
F174: ADDA #$20
F176: BCC $F104
*/
READ_HANDLER( tp84_beam_r )
{
// return cpu_getscanline();
return 255; /* always return beam position 255 */ /* JB 970829 */
}
/* JB 970829 - catch a busy loop for CPU 1
E0ED: LDA #$01
E0EF: STA $4000
E0F2: BRA $E0ED
*/
WRITE_HANDLER( tp84_catchloop_w )
{
if( cpu_get_pc()==0xe0f2 ) cpu_spinuntil_int();
}