4. VDP1 Basic Processing Reference

typedef struct SprSpStatus {
     Uint16 frameChgMode; / * Frame change mode * 1 * /
     Uint16 frameEraseMode; / * Frame erase mode * 2 * /
     Uint16 vbInterval; / * Number of V-BLANK intervals * /
     Uint16 eraseData; / * Frame buffer erase data * /
     Uint16 eraseLeftX; / * Frame buffer erase position left end * /
     Uint16 eraseTopY; / * Frame buffer erase position Upper end * /
     Uint16 eraseRightX; / * Frame buffer erase position right end * /
     Uint16 eraseBotY; / * Frame buffer erase position Lower end * /
} SprSpStatus;

* 1 Frame change mode 

#define AUTO_FRAME_CHG 0 / * Auto change * /
#define MANUAL_FRAME_CHG 1 / * Fixed interval manual change * /
#define NO_INTER_FRAME_CHG 2 / * Undefined interval manual change * /
#define NO_INTER_VBE_FRAME_CHG 3 / * Undefined due to V blank erase * /
                                    / * Interval manual change * / 

* 2 Frame erase mode 

#define OFF 0 / * Frame erase off * /
#define ON 1 / * Frame erase on * /