dino@ddsw1.UUCP (10/01/87)
Does anyone here know anything about a way to add an 'autoreversing' mechanism to a cassette tape player that doesnt' have this feature already? Any advice or pointers to information would be appreciated. -- Dino ....ihnp4!ddsw1!dino (Laura Watson)
philm@astroatc.UUCP (10/02/87)
In article <212@ddsw1.UUCP> dino@ddsw1.UUCP (Laura Watson) writes: >Does anyone here know anything about a way to add an 'autoreversing' >mechanism to a cassette tape player that doesnt' have this feature already? >Any advice or pointers to information would be appreciated. Unfortunately, most, if not all, forward-only playing cassette machines physically, mechanically and spiritually can never be retrofitted for autoreverse without major restructuring of the tape transport and electronics. Here's why: (1) In order to play the other side of a cassette after reaching the end of one side, you have to have sensors to detect the tape has reached the end of a side - most forward-only decks don't have these sensors (unless, perhaps the deck is 'auto-stop'). (2) Once the tape has played forwards, the transport must reverse and run at play speed until the end of the other side - something forward-only decks are generally incapable of doing. There's not much one can do about this one unless the deck in question has a forward/reverse transport and the manufacturer is only letting you run is one direction. (3) The deck's electronics would need an overhaul to accomodate a forward/ reverse playback (NOTE: and record and erase, if the machine records) head. Cassettes have two tracks (mono) or four tracks (stereo), one half of which are used for one side and the other track(s) for the opposite side. One side's tracks run along half of the tape - when you flip the tape over, you bring the other side's tracks to bear on the set of heads to playback, record and erase (see note above). Only one half of the tape is dealt with at a time by the standard uni-directional recorder or player. An autoreverse deck has a special set of heads that handle all of the tracks for both sides at once. When the tape reverses, the deck automatically switches the signals from the one side's portion of the heads to the other side's portion of the heads. A Picture (that may or may not help) : ----------------------------------------------------------------------------- =========================== Side 2's track(s), read with the tape going <---- =========================== Side 1's track(s), read with the tape going ----> ----------------------------------------------------------------------------- A slice of a cassette tape, normal forward tape direction ----> A standard forward-only cassette playback (or record or erase) head : --------- | | | ==== | Note that the active area of the head can only read one side of --------- the tape at a time - you have to flip the tape over to read the other side. An autoreverse cassette playback (or record or erase) head : --------- | ==== | | ==== | Note that the active area of the head can read both sides of --------- the tape at a time - however, in order to read side 2 going the right direction, the tape has to be going in reverse from the normal side 1 direction. I hope this explanation helped those who needed it and didn't bore to death those who could care less or already knew how their cassette machines work. -- Kirk : Bones ? | Phil Mason, Astronautics Technology Center Bones : He's dead Jim. | Madison, Wisconsin - "Eat Cheese or Die!" ...seismo-uwvax-astroatc!philm | I would really like to believe that my ...ihnp4-nicmad/ | employer shares all my opinions, but . . .
boris@athena.mit.edu (Boris N Goldowsky) (10/05/87)
About hacking your tape player to be bidirectional: Would it be easier, perhaps, to physically flip the tape over rather than try to retrofit the heads, motors, etc. to play it backwards? I've seen tape players that do this (though of course they were built that way in the first place). Boris Goldowsky boris@athena.mit.edu or @adam.pika.mit.edu
dino@ddsw1.UUCP (Laura Watson) (10/06/87)
In article <1555@bloom-beacon.MIT.EDU> boris@athena.mit.edu (Boris N Goldowsky) writes: >Would it be easier, perhaps, to physically flip the tape over rather than try to >retrofit the heads, motors, etc. to play it backwards? I've seen tape players >that do this (though of course they were built that way in the first place). Well, that would depend on what you were using it for. If you were trying to listen to something over and over again in your sleep, it'd be a realy pain to keep waking up to turn it over.... or if you were very busy and didn't want to have to be bothered with turning it over or would forget.... or if you were using your hands for something else and it would seriously decrease your efficiency to stop to turn it over..... Of course, as several people have suggested, the best solution is probably to buy another one. Thanks. -- ------- Laura Watson ...[ihnp4, rutgers!moss, clyde, ulysses, cbosgd]!burt!lkw ...ihnp4!ddsw1!dino May you always have the strength to enjoy your weaknesses.