YACQ!

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Not an expresssion of disgust because I added a photo to my profile I hope. :D rather Yet Another CDrom Question.

I have managed to get a CDrom player to play audio CDs (Not MP3) thanks to all the examples pointed to by people on this forum, including Ken Wilson's (Pic), YAMMP3 and others. I'm having a bit of bother with the Fast forward and Fast rewind command which does not work. I seem to remember that it is an optional feature so not all player may support it, but I have tried it on 3 different players and the command always comes back with a sense key of 05 and an ASC of 20 which means that it is an illegal command. YAMMP3 seems to do it by simply skipping 10 seconds of play every 100ms and issuing continuous play command in order to achieve the above. I'm a doing something wrong with the command? Is there something I'm overlooking? I'm attaching the relevant piece of code in the hope that someone can H.E.L.P! By the way he MSF value is only a few ms old when it gets sent to the command and the AtaPacket is cleared after sending the packet out .

ATA_scan_backward:
ldi r16,0x10 ;Bit 4 of byte 1 set indicates
sts AtaPacket+1,r16 ;backward scanning
;Byte 1=0 for forward
ATA_scan_forward:
ldi r16,0xba ;ATA Command
sts AtaPacket,r16
lds r16,TrackCurrentMSF_M ;Start scanning from current location
sts AtaPacket+3,r16 ;Set minutes in r16
lds r16,TrackCurrentMSF_S
sts AtaPacket+4,r16 ;Set seconds in r16
lds r16,TrackCurrentMSF_F
sts AtaPacket+5,r16 ;Set frame in r16
ldi r16,0x40 ;(0100 0000) AMIN, ASEC and AFRAME
sts AtaPacket+9,r16 ;format
rcall Ata_Write_Packet
rcall ATA_request_sense
ret

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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I guess no one in the know has read the above! :( or I'm sure I would have got an answer by now. I have implemented the scan command in software by skipping a few seconds of play every 200ms or so. I would still like to hear from some wise person on the matter. It seem that the scan command is well documented but not implemented by anyone. I have now tried a new cdrom (manufacture Dec 2003) and it doesn't support the command :( :(

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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Total votes: 0

Try using a message title that has some bearing on the help you require. Not the sort of subject that could appear as a spam subject line.

Suggest you read the top posting, it contains advice on how to compose a post.
Mike

Keep it simple it will not bite as hard