diff genesis.c @ 1869:dc94354eab66

Fix accuracy bugs used by Novedicus to detect BlastEm/Exodus
author Michael Pavone <pavone@retrodev.com>
date Mon, 24 Jun 2019 23:47:16 -0700
parents 6b5147f08846
children 96971b673f51
line wrap: on
line diff
--- a/genesis.c	Mon Jun 24 09:11:38 2019 -0700
+++ b/genesis.c	Mon Jun 24 23:47:16 2019 -0700
@@ -648,7 +648,7 @@
 	} else if (vdp_port < 0x18){
 		fatal_error("Illegal read from PSG  port %X\n", vdp_port);
 	} else {
-		value = vdp_test_port_read(v_context);
+		value = get_open_bus_value(&gen->header);
 	}
 	if (v_context->cycles != before_cycle) {
 		//printf("68K paused for %d (%d) cycles at cycle %d (%d) for read\n", v_context->cycles - context->current_cycle, v_context->cycles - before_cycle, context->current_cycle, before_cycle);
@@ -1012,6 +1012,10 @@
 	uint32_t address = gen->z80_bank_reg << 15 | location;
 	if (address >= 0xC00000 && address < 0xE00000) {
 		return z80_vdp_port_read(location & 0xFF, context);
+	} else if (address >= 0xA10000 && address <= 0xA10001) {
+		//Apparently version reg can be read through Z80 banked area
+		//TODO: Check rest of IO region addresses
+		return gen->version_reg;
 	} else {
 		fprintf(stderr, "Unhandled read by Z80 from address %X through banked memory area (%X)\n", address, gen->z80_bank_reg << 15);
 	}