ref: 8f5ab25e8696f51f2be8a6743edc2de68c9451d6
dir: /sys/src/games/blit/dat.h/
extern u32int curpc, irq;
extern int trace, debug;
extern ushort ram[128*1024];
extern int daddr;
extern ushort dstat;
extern uchar invert;
extern int mousex, mousey, mousebut;
extern int vblctr, uartrxctr;
extern int baud;
enum {
INTKEY = 1,
INTMOUSE = 2,
INTUART = 4,
INTVBL = 8,
};
enum {
SX = 800,
SY = 1024,
FREQ = 8000*1000,
VBLDIV = FREQ / 60,
};