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Add aux memory field

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This commit is contained in:
Peter Evans 2018-01-10 20:36:44 -06:00
parent 8898c3e59d
commit 04854d903c
3 changed files with 19 additions and 2 deletions
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9
include/apple2.h
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@ -124,6 +124,15 @@ typedef struct {
*/
vm_segment *ram2;
/*
* The Apple II may have an auxiliary RAM bank; this was possible by
* installing a card there. If you had the 80-column text card (and
* you likely did), then you got an extra kilobyte of RAM to work
* with; it was either used for the extra columns or you could take
* advantage of it for extra storage otherwise.
*/
vm_segment *aux;
/*
* The screen wherein we shall render all of our graphics.
*/

7
include/apple2.mem.h
View File

@ -39,6 +39,13 @@
*/
#define APPLE2_RAM2_SIZE 0x1000
/*
* At the highest point (with the IIe extended 80 column text card), you
* could have a whole other 64k of data in auxiliary memory. (Of which
* only 1k was needed for 80 columns!)
*/
#define APPLE2_AUX_SIZE 0x10000
/*
* This is the base address (or offset) for all bank-switched memory
*/

5
src/apple2.c
View File

@ -67,8 +67,9 @@ apple2_create(int width, int height)
// Initliaze our system ROM and separate bank-switched block of RAM
mach->rom = vm_segment_create(APPLE2_ROM_SIZE);
mach->ram2 = vm_segment_create(APPLE2_RAM2_SIZE);
if (mach->rom == NULL || mach->ram2 == NULL) {
log_critical("Could not initialize ROM / RAM2!");
mach->aux = vm_segment_create(APPLE2_AUX_SIZE);
if (mach->rom == NULL || mach->ram2 == NULL || mach->aux == NULL) {
log_critical("Could not initialize ROM / RAM2 / AUX!");
apple2_free(mach);
return NULL;
}