PTR =TEMP ;word
LEN =TEMP+2 ;word
NEXTSPR =TEMP+4
SCRX =TEMP+5
SCRY =TEMP+6
SRC =TEMP+7 ;word
DST =TEMP+9 ;word
RLE_LOW =TEMP
RLE_HIGH =TEMP+1
RLE_TAG =TEMP+2
RLE_BYTE =TEMP+3