HERCULES_WIDTH
(char *) HERCULES_VIDEO_ADDR + HERCULES_WIDTH * 2,
HERCULES_WIDTH * (HERCULES_HEIGHT - 1) * 2);
for (i = HERCULES_WIDTH * (HERCULES_HEIGHT - 1) / 2;
i < HERCULES_WIDTH * HERCULES_HEIGHT / 2;
for (i = 0; i < HERCULES_WIDTH * HERCULES_HEIGHT / 2; i++)
unsigned offset = herc_y * HERCULES_WIDTH + herc_x;
video[herc_y * HERCULES_WIDTH + herc_x]
if (herc_x >= HERCULES_WIDTH)