I just snagged DF's code for remapping the PIC. It looks like this:
#define PIC1 0x20 #define PIC2 0xA0 #define PIC1_COMMAND PIC1 #define PIC1_DATA (PIC1+1) #define PIC2_COMMAND PIC2 #define PIC2_DATA (PIC2+1) #define PIC_EOI 0x20
#define ICW1_ICW4 0x01 /* ICW4 (not) needed */ #define ICW1_SINGLE 0x02 /* Single (cascade) mode */ #define ICW1_INTERVAL4 0x04 /* Call address interval 4 (8) */ #define ICW1_LEVEL 0x08 /* Level triggered (edge) mode */ #define ICW1_INIT 0x10 /* Initialization - required! */
#define ICW4_8086 0x01 /* 8086/88 (MCS-80/85) mode */ #define ICW4_AUTO 0x02 /* Auto (normal) EOI */ #define ICW4_BUF_SLAVE 0x08 /* Buffered mode/slave */ #define ICW4_BUF_MASTER 0x0C /* Buffered mode/master */ #define ICW4_SFNM 0x10 /* Special fully nested (not) */
void remap_pics(int pic1, int pic2) { UCHAR a1, a2;
a1=inportb(PIC1_DATA); a2=inportb(PIC2_DATA);
outportb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4); io_wait(); outportb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4); io_wait(); outportb(PIC1_DATA, pic1); io_wait(); outportb(PIC2_DATA, pic2); io_wait(); outportb(PIC1_DATA, 4); io_wait(); outportb(PIC2_DATA, 2); io_wait();
outportb(PIC1_DATA, ICW4_8086); io_wait(); outportb(PIC2_DATA, ICW4_8086); io_wait();
outportb(PIC1_DATA, a1); outportb(PIC2_DATA, a2); };
I don't know what is supposed to go in io_wait so I just have an empty function for it.
I then call the above function like this: remap_pics(PIC1, PIC2)
Is this correct, and what goes in io_wait?
Thanks, K.J.
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