1 files changed, 33 insertions, 7 deletions

diff --git a/emu/memory.c b/emu/memory.c
index c9d953b..408e621 100644
--- a/emu/memory.c
+++ b/emu/memory.c
@@ -2,25 +2,51 @@
 
 #include <stdio.h>
 
-void memory_init( memory_t *memory )
+void memory_init( memory_t *memory, seg7_t *seg )
 {
 	memory->read = memory_read;
 	memory->write = memory_write;
+	memory->seg = seg;
 }
 
 uint8_t memory_read( memory_t *memory, uint16_t addr )
 {
-	return memory->cell[addr];
+	if( addr <= 0x3FFF ) {
+		// RAM access
+		return memory->cell[addr];
+	} else if( addr <= 0x8000 ) {
+		return seg7_read( memory->seg, addr );
+	} else {
+		// ROM access
+		return memory->cell[addr];
+	}
 }
 
 void memory_write( memory_t *memory, uint16_t addr, uint8_t data )
-{	
-	memory->cell[addr] = data;
+{
+	if( addr <= 0x3FFF ) {
+		// RAM access
+		memory->cell[addr] = data;
+	} else if( addr <= 0x8000 ) {
+		seg7_write( memory->seg, addr, data );
+	} else {
+		// ignore writes to ROM
+	}
 }
 
 void memory_load( memory_t *memory, uint16_t addr, uint16_t size, const char *filename )
 {
-	FILE *f = fopen( filename, "rb" );
-	fread( &memory->cell[addr], size, 1, f );
-	fclose( f );
+	if( addr >= 0x8000 ) {
+		FILE *f = fopen( filename, "rb" );
+		if( f == NULL ) {
+			fprintf( stderr, "ERROR: Unable to open ROM file '%s'\n", filename );
+			exit( EXIT_FAILURE );
+		}
+		fread( &memory->cell[addr], size, 1, f );
+		fclose( f );
+		fprintf( stderr, "INFO: Loaded firware from '%s' of size %d starting on address %04X\n",
+			filename, size, addr );
+	} else {
+		fprintf( stderr, "ERROR: Cannot load firmware into RAM at address %04X\n", addr );
+	}
 }