Mercurial > repos > blastem

comparison blastem.c @ 753:cee1275f5d08

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Lame placeholder support for floating bus bits of IO hardware. Needs to be replaced with prefetch based values
author Michael Pavone <pavone@retrodev.com>
date Thu, 25 Jun 2015 09:02:42 -0700
parents 296ddfcf0d43
children bb60259e8edf
comparison
equal deleted inserted replaced
752:296ddfcf0d43 753:cee1275f5d08
641 value = 0xFF; 641 value = 0xFF;
642 } 642 }
643 } else { 643 } else {
644 if (location == 0x1100) { 644 if (location == 0x1100) {
645 value = z80_enabled ? !z80_get_busack(gen->z80, context->current_cycle) : !gen->z80->busack; 645 value = z80_enabled ? !z80_get_busack(gen->z80, context->current_cycle) : !gen->z80->busack;
646 //TODO: actual pre-fetch emulation
647 value |= 0x4E;
646 dprintf("Byte read of BUSREQ returned %d @ %d (reset: %d)\n", value, context->current_cycle, gen->z80->reset); 648 dprintf("Byte read of BUSREQ returned %d @ %d (reset: %d)\n", value, context->current_cycle, gen->z80->reset);
647 } else if (location == 0x1200) { 649 } else if (location == 0x1200) {
648 value = !gen->z80->reset; 650 value = !gen->z80->reset;
649 } else { 651 } else {
650 value = 0xFF; 652 value = 0xFF;
660 uint16_t value = io_read(location, context); 662 uint16_t value = io_read(location, context);
661 if (location < 0x10000 || (location & 0x1FFF) < 0x100) { 663 if (location < 0x10000 || (location & 0x1FFF) < 0x100) {
662 value = value | (value << 8); 664 value = value | (value << 8);
663 } else { 665 } else {
664 value <<= 8; 666 value <<= 8;
667 //TODO: actual pre-fetch emulation
668 value |= 0x73;
665 } 669 }
666 return value; 670 return value;
667 } 671 }
668 672
669 void * z80_write_ym(uint32_t location, void * vcontext, uint8_t value) 673 void * z80_write_ym(uint32_t location, void * vcontext, uint8_t value)