Recovering Cassette Tape Records

Grant Stockly grant at stockly.com
Tue Jan 2 16:26:47 CST 2007


>If it's any use to you, I can send some tools to work with this type of
>data (change record size, load address, convert to binary, set fill
>values etc.). I can also give you assembler/disassemblers which will
>work with MHX directly.

That would be great!  Just send it to my list address.  I have no size limit.

>PS: I'd like to get a copy of the data once you get it extracted.

I have a memory dump of basic loaded and unitialized from 0000-1FFF, but I 
want the original data extracted off the tape.

I hooked a 232 transciever and inverter up to the demodulated output from 
the KCACR (right at the 1013 ACIA IC) and it wasn't 300bps.  I had a 2.5ms 
bit clock and it should have been around 3.3ms.

I am going crazy to the point of completely ignoring the following fact.  I 
have 7-8 WAV files on my computer.  I started recording the second I pushed 
play, which was right at the beginning of the tape.  I stopped recording 
when it lost the carrier.

I have 3 recordings that are 13:30 minutes long and 3-4 that are 10:17 
long.  The KCACR will load basic with either length, although at 13:30 
minutes it is very sensitive to tape quality it seems.

I have a very nice tape deck with dc servo controlled motors.  This is very 
disapointing to me.  It makes me cry to think about it...  : (  I want a 
perfect quality recording of the tape and it kills me to think I have to 
hook one of my "junk" players up to the computer to get it...

I think the reason that the demodulated output is not 300bps is the KCACR 
is locking onto the tape speed?  The KCACR is supposed to handle a +-20% 
speed variance.  The bitclock must be provided to the 1013 ACIA.  I don't 
have the manual for the KCACR yet, so I have no idea...

My idea to get a PERFECT MITS basic sound file is to recover the S records 
and generate a new sound file using the KCS.EXE program found on the web. 
Comments?

Grant 




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