From: Vladimir Pantelic <pan_at_nt.tu-darmstadt.de>
Date: Tue, 22 Feb 2005 18:23:11 +0100

BlueChip wrote:

> Possibly the biggest clue is this snippet from the m3po version history
> [numbered by me for clarity]:
>
> 2.10 >> V2.11
> [Bugfixes]
> 1. party lock - eject cds while lock complete
> 2. pitch and speed of playback was wrong
> 3. minor shuffle bug fixed
> 4. more files on one CD supported
>
> When I read that I get:
> 3. this list includes all changes to firmware
> 4. a buffer/malloc/bss got bigger somewhere
> 2. the pitch/speed code was tweaked
> 1. & 3. two other bits of code also changed

OK, so you don't know how it is done, you just guess from the release notes :-)

> Ever play "spot the difference" on a pub quiz machine? ...One of the
> differences directly effects the pitch/speed change ;)

Look at the MAS datasheet, there is an internal register that is used to tell
the MAS what frequency value the external crystal has, if you set that one
wrong you get a higher/lower pitch and speed. My guess is that this value
was slightly off and was corrected. Unfortunately the value range of this register
does not allow for the large range of the speed change that the M3PO features.

> My next hit is a mind-numbingly simple moment of genuis called FTEXT, an
> ancient DOS util which isolates ascii strings in unencrypted binary
> files - you would not be surprised at how far you can get by simply
> tracing things from the point they print "speed" on the screen.

it is called "strings" if you use Linux/Unix, maybe ancient but still included
in every distro.

> Grab yourself a good hex editor [and please tell me what it is - LOL - I
> have NEVER found a _good_ hex editor (or calculator) for windows] and
> "hit the bits" as they say.

Editor: WinHex, for the calculator I prefer real HW.

Regards,

Vladimir
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Received on 2005-02-22