1 files changed, 41 insertions, 0 deletions
diff --git a/int10vga.h b/int10vga.h
new file mode 100644
index 0000000..f3e0a07
--- /dev/null
+++ b/int10vga.h
@@ -0,0 +1,41 @@
+#ifndef INT10_H
+#define INT10_H
+
+#include <stdint.h>
+
+#define BIOS_DATA_AREA_SEGMENT 0x40
+
+static uint8_t int10_get_video_mode(uint8_t *screenwidth, uint8_t *videopage);
+#pragma aux int10_get_video_mode = \
+	"mov al, 0" \
+	"mov ah, 0x0F" \
+	"int 0x10" \
+	"mov ss:[si], ah" \
+	"mov ss:[di], bh" \
+	__parm [si] [di] \
+	__value [al] \
+	__modify [ax bh]
+
+static inline uint16_t bda_get_word(unsigned int offset) {
+	uint16_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, offset);
+	return *p;
+}
+
+static inline uint8_t bda_get_byte(unsigned int offset) {
+	uint8_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, offset);
+	return *p;
+}
+
+#define bda_get_video_mode()      bda_get_byte(0x49)
+#define bda_get_num_columns()     bda_get_word(0x4a)
+#define bda_get_video_page_size() bda_get_word(0x4c)
+//#define bda_get_tick_count()      bda_get_dword(0x6c)
+#define bda_get_tick_count_lo()   bda_get_word(0x6c)
+
+static inline uint16_t __far * get_video_char(uint8_t page, unsigned int x, unsigned int y)
+{
+	return MK_FP(0xB800, (page * bda_get_video_page_size())
+	                     + ((y * bda_get_num_columns()) + x) * 2);
+}
+
+#endif