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Begin adding support for memory soft switches

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This commit is contained in:
Peter Evans 2018-01-16 16:34:38 -06:00
parent 2c39120098
commit 603ad7a036
2 changed files with 150 additions and 0 deletions
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9
src/apple2.dbuf.c
View File

@ -82,3 +82,12 @@ apple2_dbuf_map(vm_segment *segment)
vm_segment_write_map(segment, addr, apple2_dbuf_write);
}
}
/*
* Handle all read switches for display buffer code. Some switches
* respond to either reads _or_ writes, so you may see some cases
* duplicated in the write map.
*/
SEGMENT_READER(apple2_dbuf_switch_read)
{
}

141
src/apple2.mem.c
View File

@ -9,6 +9,28 @@
#include "apple2.mem.h"
#include "objstore.h"
static size_t switch_reads[] = {
0xC013,
0xC014,
0xC018,
0xC01C,
0xC01D,
};
static size_t switch_writes[] = {
0xC000,
0xC001,
0xC002,
0xC003,
0xC004,
0xC005,
0xC054,
0xC055,
0xC056,
0xC057,
0xC059,
};
/*
* Set the memory map functions for main memory in an apple2 machine
*/
@ -16,6 +38,7 @@ void
apple2_mem_map(apple2 *mach, vm_segment *segment)
{
size_t addr;
int i, rlen, wlen;
vm_segment_set_map_machine(mach);
@ -36,6 +59,17 @@ apple2_mem_map(apple2 *mach, vm_segment *segment)
vm_segment_read_map(segment, addr, apple2_mem_zp_read);
vm_segment_write_map(segment, addr, apple2_mem_zp_write);
}
rlen = sizeof(switch_reads) / sizeof(size_t);
wlen = sizeof(switch_writes) / sizeof(size_t);
for (i = 0; i < rlen; i++) {
vm_segment_read_map(segment, switch_reads[i], apple2_mem_switch_read);
}
for (i = 0; i < wlen; i++) {
vm_segment_write_map(segment, switch_writes[i], apple2_mem_switch_write);
}
}
/*
@ -109,3 +143,110 @@ SEGMENT_WRITER(apple2_mem_zp_write)
segment->memory[addr] = value;
}
/*
* Handle all soft switches that ask for the status of certain memory
* conditions.
*/
SEGMENT_READER(apple2_mem_switch_read)
{
apple2 *mach = (apple2 *)_mach;
switch (addr) {
case 0xC013:
return mach->memory_mode & MEMORY_READ_AUX
? 0x80
: 0x00;
case 0xC014:
return mach->memory_mode & MEMORY_WRITE_AUX
? 0x80
: 0x00;
case 0xC018:
return mach->memory_mode & MEMORY_80STORE
? 0x80
: 0x00;
case 0xC01C:
return mach->memory_mode & MEMORY_PAGE2
? 0x80
: 0x00;
case 0xC01D:
return mach->memory_mode & MEMORY_HIRES
? 0x80
: 0x00;
}
// ???
return 0;
}
/*
* Change memory settings based on the soft switches defined in the tech
* reference
*/
SEGMENT_WRITER(apple2_mem_switch_write)
{
apple2 *mach = (apple2 *)_mach;
switch (addr) {
case 0xC003:
apple2_set_memory_mode(mach,
mach->memory_mode | MEMORY_READ_AUX);
break;
case 0xC002:
apple2_set_memory_mode(mach,
mach->memory_mode & ~MEMORY_READ_AUX);
break;
case 0xC005:
apple2_set_memory_mode(mach,
mach->memory_mode & MEMORY_WRITE_AUX);
break;
case 0xC004:
apple2_set_memory_mode(mach,
mach->memory_mode & ~MEMORY_WRITE_AUX);
break;
case 0xC001:
apple2_set_memory_mode(mach,
mach->memory_mode & MEMORY_80STORE);
break;
case 0xC000:
apple2_set_memory_mode(mach,
mach->memory_mode & ~MEMORY_80STORE);
break;
case 0xC055:
apple2_set_memory_mode(mach,
mach->memory_mode & MEMORY_PAGE2);
break;
case 0xC054:
apple2_set_memory_mode(mach,
mach->memory_mode & ~MEMORY_PAGE2);
break;
// NOTE: in one place, the technical reference says $C057 is the
// soft switch to enable HIRES. In one other place, it says
// $C059. I'm assuming it's either one... It's otherwise
// consistent when mentioning soft switches in more than one
// table.
case 0xC059:
case 0xC057:
apple2_set_memory_mode(mach,
mach->memory_mode & MEMORY_HIRES);
break;
case 0xC056:
apple2_set_memory_mode(mach,
mach->memory_mode & ~MEMORY_HIRES);
break;
}
}