Format of CD-ROM control block: Offset Size Description ) 00h BYTE data being requested (see #01448) ---function 00h--- 01h DWORD device driver header address (see also AH=52h,#01646) ---function 01h--- 01h BYTE (call) addressing mode 00h HSG 01h Red Book 02h DWORD current location of drive's head logical sector number in HSG mode frame/second/minute/unused in Red Book mode (HSG sector = minute * 4500 + second * 75 + frame - 150) ---function 03h--- 01h N BYTEs undefined as of 5 Aug 88 specification ---function 04h--- 01h BYTE input channel (0-3) for output channel 0 02h BYTE volume for output channel 0 03h BYTE input channel (0-3) for output channel 1 04h BYTE volume for output channel 1 05h BYTE input channel (0-3) for output channel 2 06h BYTE volume for output channel 2 07h BYTE input channel (0-3) for output channel 3 08h BYTE volume for output channel 3 Notes: output channels 0 and 1 are left and right, 2 and 3 are left prime and right prime; a volume of 00h is off the default setting is for each input channel to be assigned to the same-numbered output channel at full (FFh) volume ---function 05h--- 01h BYTE number of bytes read 02h 128 BYTEs buffer for drive bytes ---function 06h--- 01h DWORD device parameters (see #01450) ---function 07h--- 01h BYTE (call) read mode 00h cooked 01h raw 02h WORD (return) sector size in bytes ---function 08h--- 01h DWORD volume size in sectors BUGS: Aztech device driver v1.10 and v1.27 (at least) return the last sector number, i.e. total number of sectors - 1 Windows95 returns the total number of sectors + 150 (see the Red Book to HSG conversion formula at function 01h to understand why this happens) ---function 09h--- 01h BYTE media change status 00h don't know 01h media unchanged FFh media has been changed ---function 0Ah--- 01h BYTE lowest audio track number 02h BYTE highest audio track number 03h DWORD start address of lead-out track (Red Book format) --function 0Bh--- 01h BYTE (call) track number 02h DWORD starting point of track (Red Book format) 06h BYTE track control info bits 15,14,12: track type (notice: bits not contiguous!) 000 two audio channels, no pre-emphasis 001 two audio channels with pre-emphasis 010 data track 100 four audio channels, no pre-emphasis 101 four audio channels with pre-emphasis other reserved bit 13: digital copy permitted ---function 0Ch--- 01h BYTE CONTROL and ADR byte (as received from drive) 02h BYTE track number 03h BYTE point or index 04h BYTE minute \ 05h BYTE second > running time within track 06h BYTE frame / 07h BYTE zero 08h BYTE "AMIN" or "PMIN" \ 09h BYTE "ASEC" or "PSEC" > running time on disk 0Ah BYTE "AFRAME" or "PFRAME" / ---function 0Dh--- 01h DWORD starting frame address (Red Book format) 05h DWORD transfer address 09h DWORD number of sectors to read Note: copies 96 bytes of sub-channel info per sector into buffer ---function 0Eh--- 01h BYTE CONTROL and ADR byte 02h 7 BYTEs UPC/EAN code (13 BCD digits,low-order nybble of last byte is 0) 09h BYTE zero 0Ah BYTE "AFRAME" ---function 0Fh--- ??? documentation not yet available 01h WORD pause status (0000h not paused, 0001h paused) 03h DWORD audio play start address 07h DWORD ??? audio play length or end address