CR63
uni_wr(sc, VIACR, CR63, 0x00);
{VIACR, CR63, 0xFF, 0x00}, /* Secondary Display Starting Address */
{VIACR,CR63,0xFF,0x00}, /* Secondary Display Starting Address*/
{VIACR, CR63, 0xFF, 0x00}, /* Secondary Display Starting Address */
{VIACR, CR63, 0xFF, 0x00}, /* Secondary Display Starting Address */