1504 INT 15 - SYSTEM - BUILD ABIOS SYSTEM PARAMETER TABLE (PS)
1504 INT 15 - Amstrad PC1512 - WRITE VDU COLOR PLANE READ REGISTER
1504 INT 15 - VMiX - "sys_vprintf" - FORMATTED OUTPUT TO STREAM
1504 INT 15 - MultiDOS Plus - SEND MESSAGE TO ANOTHER TASK