6502/erc-c
1
0
Fork 0
mirror of https://github.com/pevans/erc-c.git synced 2024-11-16 09:07:05 +00:00
Code Issues Projects Releases Wiki Activity

Finish refactor to separate bank_switch and memory_mode

Browse Source 
There is one failing test, which I expect to fail at this point; that's
because we need to write a read/write map function for the stack and
zero page so that they use aux memory when BANK_ALTZP is on, and main
memory when not.
This commit is contained in:
Peter Evans 2018-01-12 21:04:21 -06:00
parent ceccacfbc8
commit c953616a71
5 changed files with 88 additions and 84 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
include/apple2.h
View File

@ -153,13 +153,10 @@ enum bank_switch {
BANK_WRITE = 0x2,
/*
* When on, the $Dnnn hexapage will use the first RAM bank for
* reads and/or writes. All other RAM access in bank-switched memory
* will still go to bank 1 RAM, with respect to BANK_RAM when it
* comes to reads. (The default behavior is actually to use bank 2
* RAM for the $D range.)
* When this is on, we will use bank 2 RAM when accessing the $Dnnn
* range; otherwise, we use bank 1 (as you might guess).
*/
BANK_RAM1 = 0x4,
BANK_RAM2 = 0x4,
/*
* This is a weird little bit. When BANK_ALTZP is on, the zero page
@ -264,8 +261,9 @@ extern void apple2_press_key(apple2 *, vm_8bit);
extern void apple2_release_key(apple2 *);
extern void apple2_reset(apple2 *);
extern void apple2_run_loop(apple2 *);
extern void apple2_set_color(apple2 *, int);
extern void apple2_set_bank_switch(apple2 *, vm_8bit);
extern void apple2_set_color(apple2 *, int);
extern void apple2_set_memory_mode(apple2 *, vm_8bit);
extern void apple2_set_video(apple2 *, int);
#endif

52
src/apple2.c
View File

@ -154,27 +154,42 @@ apple2_create(int width, int height)
void
apple2_set_bank_switch(apple2 *mach, vm_8bit flags)
{
int have_aux = mach->bank_switch & MEMORY_AUX;
int flags_aux = flags & MEMORY_AUX;
if (flags_aux && !have_aux) {
// Switch to auxiliary memory.
mos6502_set_memory(mach->cpu, mach->aux, mach->aux);
// We need to copy page 0 and 1 from main over to aux.
// If we already have BANK_ALTZP, and the flags we're setting do
// _not_ have BANK_ALTZP, then we need to copy aux's zero page and
// stack into main. But if we don't have BANK_ALTZP, and flags
// _does_, then we have to do the inverse: copy main's zero page and
// stack into aux.
if (mach->bank_switch & BANK_ALTZP) {
if (~flags & BANK_ALTZP) {
vm_segment_copy(mach->main, mach->aux, 0, 0, 0x200);
}
} else if (flags & BANK_ALTZP) {
vm_segment_copy(mach->aux, mach->main, 0, 0, 0x200);
} else if (!flags_aux && have_aux) {
// Switching back to main memory
mos6502_set_memory(mach->cpu, mach->main, mach->main);
// And, like above, we need to copy page 0 and 1 from aux back
// to main.
vm_segment_copy(mach->main, mach->aux, 0, 0, 0x200);
}
mach->bank_switch = flags;
}
/*
* Set the memory mode of the apple machine. This may cause us to change
* some behavior (i.e. start using or stop using auxiliary memory).
*/
void
apple2_set_memory_mode(apple2 *mach, vm_8bit flags)
{
vm_segment *rmem = NULL,
*wmem = NULL;
mach->memory_mode = flags;
// We may need to change which segments the CPU can read from or
// write to, based upon the below flags.
rmem = (flags & MEMORY_READ_AUX) ? mach->aux : mach->main;
wmem = (flags & MEMORY_WRITE_AUX) ? mach->aux : mach->main;
mos6502_set_memory(mach->cpu, rmem, wmem);
}
/*
* Return true if we are in a state that the apple2 would consider
* double resolution. (In practice, this refers to horizontal screen
@ -248,12 +263,9 @@ apple2_reset(apple2 *mach)
// Switch video mode back to 40 column text
apple2_set_video(mach, VIDEO_40COL_TEXT);
// Default to:
// - read from ROM
// - write to RAM
// - use bank 2 for $Dxxx hexapage
// Switch us back to defaults
apple2_set_bank_switch(mach, BANK_DEFAULT);
apple2_set_memory_mode(mach, MEMORY_NOMINAL);
apple2_set_memory_mode(mach, MEMORY_DEFAULT);
}
/*

44
src/apple2.mem.c
View File

@ -16,7 +16,7 @@ SEGMENT_READER(apple2_mem_read_bank)
mach = (apple2 *)_mach;
if (mach->bank_switch & MEMORY_ROM) {
if (~mach->bank_switch & BANK_RAM) {
// We need to account for the difference in address location
// before we can successfully get any data from ROM.
return vm_segment_get(mach->rom, addr - APPLE2_BANK_OFFSET);
@ -26,7 +26,7 @@ SEGMENT_READER(apple2_mem_read_bank)
// that you can access through bank-switching in the $D000 - $DFFF
// range, which is actually held at the _end_ of memory beyond the
// 64k mark.
if (addr < 0xE000 && mach->bank_switch & MEMORY_RAM2) {
if (addr < 0xE000 && mach->bank_switch & BANK_RAM2) {
// The same caution holds for getting data from the
// second RAM bank.
return segment->memory[addr + 0x3000];
@ -48,7 +48,7 @@ SEGMENT_WRITER(apple2_mem_write_bank)
mach = (apple2 *)_mach;
// No writes are allowed... sorry!
if (~mach->bank_switch & MEMORY_WRITE) {
if (~mach->bank_switch & BANK_WRITE) {
return;
}
@ -62,7 +62,7 @@ SEGMENT_WRITER(apple2_mem_write_bank)
// In this case, we need to assign the value at the 64-68k range at
// the end of memory; this is just a simple offset from the given
// address.
if (addr < 0xE000 && mach->bank_switch & MEMORY_RAM2) {
if (addr < 0xE000 && mach->bank_switch & BANK_RAM2) {
segment->memory[addr + 0x3000] = value;
return;
}
@ -195,64 +195,62 @@ SEGMENT_READER(apple2_mem_read_bank_switch)
// these soft switches is not actually to read anything useful,
// but simply to change the bank switch mode.
case 0xC080:
apple2_set_bank_switch(mach, MEMORY_RAM2);
apple2_set_bank_switch(mach, BANK_RAM | BANK_RAM2);
return 0;
case 0xC081:
if (last_addr == addr) {
apple2_set_bank_switch(mach,
MEMORY_ROM | MEMORY_WRITE | MEMORY_RAM2);
apple2_set_bank_switch(mach, BANK_WRITE | BANK_RAM2);
}
return 0;
case 0xC082:
apple2_set_bank_switch(mach, MEMORY_ROM | MEMORY_RAM2);
apple2_set_bank_switch(mach, BANK_RAM2);
return 0;
case 0xC083:
if (last_addr == addr) {
apple2_set_bank_switch(mach, MEMORY_WRITE | MEMORY_RAM2);
apple2_set_bank_switch(mach, BANK_RAM | BANK_WRITE | BANK_RAM2);
}
return 0;
// Conversely, the $C088 - $C08B range control memory access
// while using bank 1 RAM.
case 0xC088:
// The 0 means there are no special privileges; reads are to
// RAM, writes are disabled, and we are using bank 1 memory.
apple2_set_bank_switch(mach, 0);
apple2_set_bank_switch(mach, BANK_RAM);
return 0;
case 0xC089:
if (last_addr == addr) {
apple2_set_bank_switch(mach, MEMORY_ROM | MEMORY_WRITE);
apple2_set_bank_switch(mach, BANK_WRITE);
}
return 0;
case 0xC08A:
apple2_set_bank_switch(mach, MEMORY_ROM);
apple2_set_bank_switch(mach, BANK_DEFAULT);
return 0;
case 0xC08B:
if (last_addr == addr) {
apple2_set_bank_switch(mach, MEMORY_WRITE);
apple2_set_bank_switch(mach, BANK_RAM | BANK_WRITE);
}
return 0;
// Return high on the 7th bit if we're using bank 2 memory
case 0xC011:
return mach->bank_switch & MEMORY_RAM2
return mach->bank_switch & BANK_RAM2
? 0x80
: 0x00;
// Return high on 7th bit if we're reading RAM
case 0xC012:
return ~mach->bank_switch & MEMORY_ROM
return mach->bank_switch & BANK_RAM
? 0x80
: 0x00;
// Return high on the 7th bit if we're using aux memory
// Return high on the 7th bit if we are using the zero page and
// stack from aux memory.
case 0xC016:
return mach->bank_switch & MEMORY_AUX
return mach->bank_switch & BANK_ALTZP
? 0x80
: 0x00;
}
@ -270,16 +268,16 @@ SEGMENT_WRITER(apple2_mem_write_bank_switch)
apple2 *mach = (apple2 *)_mach;
switch (addr) {
// Turn on auxiliary memory
// Turn on auxiliary memory for zero page + stack
case 0xC008:
apple2_set_bank_switch(mach,
mach->bank_switch | MEMORY_AUX);
mach->bank_switch | BANK_ALTZP);
return;
// Disable auxiliary memory
// Disable auxiliary memory for zero page + stack
case 0xC009:
apple2_set_bank_switch(mach,
mach->bank_switch & ~MEMORY_AUX);
mach->bank_switch & ~BANK_ALTZP);
return;
}

11
tests/apple2.c
View File

@ -121,29 +121,26 @@ Test(apple2, set_bank_switch)
{
apple2_set_bank_switch(mach, 0);
cr_assert_eq(mach->bank_switch, 0);
apple2_set_bank_switch(mach, MEMORY_ROM | MEMORY_WRITE | MEMORY_RAM2);
cr_assert_eq(mach->bank_switch, MEMORY_ROM | MEMORY_WRITE | MEMORY_RAM2);
apple2_set_bank_switch(mach, BANK_WRITE | BANK_RAM2);
cr_assert_eq(mach->bank_switch, BANK_WRITE | BANK_RAM2);
mos6502_set(mach->cpu, 0x1, 111);
mos6502_set(mach->cpu, 0x101, 222);
apple2_set_bank_switch(mach, MEMORY_AUX);
cr_assert_eq(mach->cpu->rmem, mach->aux);
apple2_set_bank_switch(mach, BANK_ALTZP);
cr_assert_eq(mos6502_get(mach->cpu, 0x1), 111);
cr_assert_eq(mos6502_get(mach->cpu, 0x101), 222);
mos6502_set(mach->cpu, 0x1, 222);
mos6502_set(mach->cpu, 0x101, 101);
apple2_set_bank_switch(mach, 0);
cr_assert_eq(mach->cpu->rmem, mach->main);
apple2_set_bank_switch(mach, BANK_DEFAULT);
cr_assert_eq(mos6502_get(mach->cpu, 0x1), 222);
cr_assert_eq(mos6502_get(mach->cpu, 0x101), 101);
}
Test(apple2, reset)
{
apple2_set_bank_switch(mach, MEMORY_ROM);
vm_segment_set(mach->rom, 0x2FFC, 0x34);
vm_segment_set(mach->rom, 0x2FFD, 0x12);
apple2_reset(mach);

53
tests/apple2.mem.c
View File

@ -64,7 +64,7 @@ Test(apple2_mem, read_bank)
// Test that setting a value in the rom segment is returned to us
// when addressing from main memory
apple2_set_bank_switch(mach, MEMORY_ROM | MEMORY_WRITE);
apple2_set_bank_switch(mach, BANK_WRITE);
val = 123;
vm_segment_set(mach->rom, 0x77, val);
val = vm_segment_get(mach->rom, 0x77);
@ -74,7 +74,7 @@ Test(apple2_mem, read_bank)
// value in memory... but, as a twist, also check that the value is
// not set in ROM nor in RAM2.
val = 222;
apple2_set_bank_switch(mach, MEMORY_WRITE);
apple2_set_bank_switch(mach, BANK_RAM | BANK_WRITE);
vm_segment_set(mach->main, 0xD077, val);
cr_assert_eq(vm_segment_get(mach->main, 0xD077), val);
cr_assert_neq(vm_segment_get(mach->rom, 0x77), val);
@ -85,7 +85,7 @@ Test(apple2_mem, read_bank)
// if it's there when addressing from main memory in the $Dnnn
// range.
val = 111;
apple2_set_bank_switch(mach, mach->bank_switch | MEMORY_RAM2);
apple2_set_bank_switch(mach, mach->bank_switch | BANK_RAM2);
vm_segment_set(mach->main, 0x10077, val);
cr_assert_eq(vm_segment_get(mach->main, 0xD077), val);
}
@ -100,12 +100,11 @@ Test(apple2_mem, write_bank)
{
vm_8bit right, wrong;
// In BANK_ROM mode, we expect that updates to ROM will never be
// In BANK_DEFAULT mode, we expect that updates to ROM will never be
// successful (after all, it wouldn't be read-only memory if they
// were).
right = 123;
wrong = 222;
apple2_set_bank_switch(mach, MEMORY_ROM);
vm_segment_set(mach->rom, 0x77, right);
vm_segment_set(mach->main, 0xD077, wrong);
cr_assert_eq(vm_segment_get(mach->rom, 0x77), right);
@ -114,7 +113,7 @@ Test(apple2_mem, write_bank)
// RAM1 is the main bank; it's all 64k RAM in one chunk.
right = 111;
wrong = 232;
apple2_set_bank_switch(mach, MEMORY_WRITE);
apple2_set_bank_switch(mach, BANK_RAM | BANK_WRITE);
vm_segment_set(mach->main, 0xD078, right);
vm_segment_set(mach->main, 0x10078, wrong);
cr_assert_eq(vm_segment_get(mach->main, 0xD078), right);
@ -124,7 +123,7 @@ Test(apple2_mem, write_bank)
// ($D000..$DFFF) is in ram2.
right = 210;
wrong = 132;
apple2_set_bank_switch(mach, mach->bank_switch | MEMORY_RAM2);
apple2_set_bank_switch(mach, mach->bank_switch | BANK_RAM2);
vm_segment_set(mach->main, 0x10073, wrong);
vm_segment_set(mach->main, 0xD073, right);
cr_assert_eq(vm_segment_get(mach->main, 0x10073), right);
@ -133,65 +132,65 @@ Test(apple2_mem, write_bank)
Test(apple2_mem, read_bank_switch)
{
vm_segment_get(mach->main, 0xC080);
cr_assert_eq(mach->bank_switch, MEMORY_RAM2);
cr_assert_eq(mach->bank_switch, BANK_RAM | BANK_RAM2);
// This (and a few others) are trickier to test, as they require
// consecutive reads to trigger.
vm_segment_get(mach->main, 0xC081);
cr_assert_neq(mach->bank_switch, MEMORY_ROM | MEMORY_WRITE | MEMORY_RAM2);
cr_assert_neq(mach->bank_switch, BANK_WRITE | BANK_RAM2);
mach->cpu->last_addr = 0xC081;
vm_segment_get(mach->main, 0xC081);
cr_assert_eq(mach->bank_switch, MEMORY_ROM | MEMORY_WRITE | MEMORY_RAM2);
cr_assert_eq(mach->bank_switch, BANK_WRITE | BANK_RAM2);
vm_segment_get(mach->main, 0xC082);
cr_assert_eq(mach->bank_switch, MEMORY_ROM | MEMORY_RAM2);
cr_assert_eq(mach->bank_switch, BANK_RAM2);
// Another that needs consecutives
vm_segment_get(mach->main, 0xC083);
cr_assert_neq(mach->bank_switch, MEMORY_WRITE | MEMORY_RAM2);
cr_assert_neq(mach->bank_switch, BANK_RAM | BANK_WRITE | BANK_RAM2);
mach->cpu->last_addr = 0xC083;
vm_segment_get(mach->main, 0xC083);
cr_assert_eq(mach->bank_switch, MEMORY_WRITE | MEMORY_RAM2);
cr_assert_eq(mach->bank_switch, BANK_RAM | BANK_WRITE | BANK_RAM2);
vm_segment_get(mach->main, 0xC088);
cr_assert_eq(mach->bank_switch, 0);
cr_assert_eq(mach->bank_switch, BANK_RAM);
// You get the idea
vm_segment_get(mach->main, 0xC089);
cr_assert_neq(mach->bank_switch, MEMORY_ROM | MEMORY_WRITE);
cr_assert_neq(mach->bank_switch, BANK_WRITE);
mach->cpu->last_addr = 0xC089;
vm_segment_get(mach->main, 0xC089);
cr_assert_eq(mach->bank_switch, MEMORY_ROM | MEMORY_WRITE);
cr_assert_eq(mach->bank_switch, BANK_WRITE);
vm_segment_get(mach->main, 0xC08A);
cr_assert_eq(mach->bank_switch, MEMORY_ROM);
cr_assert_eq(mach->bank_switch, BANK_DEFAULT);
vm_segment_get(mach->main, 0xC08B);
cr_assert_neq(mach->bank_switch, MEMORY_WRITE);
cr_assert_neq(mach->bank_switch, BANK_RAM | BANK_WRITE);
mach->cpu->last_addr = 0xC08B;
vm_segment_get(mach->main, 0xC08B);
cr_assert_eq(mach->bank_switch, MEMORY_WRITE);
cr_assert_eq(mach->bank_switch, BANK_RAM | BANK_WRITE);
mach->bank_switch = MEMORY_RAM2;
mach->bank_switch = BANK_RAM | BANK_RAM2;
cr_assert_eq(vm_segment_get(mach->main, 0xC011), 0x80);
mach->bank_switch = 0;
mach->bank_switch = BANK_DEFAULT;
cr_assert_eq(vm_segment_get(mach->main, 0xC011), 0x00);
mach->bank_switch = 0;
mach->bank_switch = BANK_RAM;
cr_assert_eq(vm_segment_get(mach->main, 0xC012), 0x80);
mach->bank_switch = MEMORY_ROM;
mach->bank_switch = BANK_DEFAULT;
cr_assert_eq(vm_segment_get(mach->main, 0xC012), 0x00);
mach->bank_switch = MEMORY_AUX;
mach->bank_switch = BANK_ALTZP;
cr_assert_eq(vm_segment_get(mach->main, 0xC016), 0x80);
mach->bank_switch = 0;
mach->bank_switch = BANK_DEFAULT;
cr_assert_eq(vm_segment_get(mach->main, 0xC016), 0x00);
}
Test(apple2_mem, write_bank_switch)
{
vm_segment_set(mach->main, 0xC008, 1);
cr_assert_eq(mach->bank_switch & MEMORY_AUX, MEMORY_AUX);
cr_assert_eq(mach->bank_switch & BANK_ALTZP, BANK_ALTZP);
vm_segment_set(mach->main, 0xC009, 1);
cr_assert_eq(mach->bank_switch & MEMORY_AUX, 0);
cr_assert_eq(mach->bank_switch & BANK_ALTZP, 0);
}
Test(apple2_mem, init_peripheral_rom)