Print_Str_hwyx ($F373)

This routine prints a single string (up to an 0x80). The parameter block describing the string is pointed to by the U register. The format for the parameter block is as follows:

height, width, rel y, rel x, string, 0x80



DP = $D0

U-reg points to the string list



U-reg points to the byte after the terminating 0x80

D-reg, X-reg trashed