TAPClean: multi-title support added for “Power Load”

Some time ago, Paul submitted an example of a tape with two “Power Load” titles in it, part of the “Mini Office” software package.

Today I decided to extend the “Power Load” scanner in TAPClean, giving it the ability to correctly process more than one such titles within the same tape image. The process is rather robust but I will have to do some regression testing in order to figure out the ideal value for what I refer to as the “backtrack” value. This is essentially the amount of TAP bytes between the start of the CBM Data file that holds the turbo loader and the start of the relevant turbo file itself.
In fact, it’s pretty common that at least two whole CBM files precede a single “Power Load” file, the second of which contains the turbo loader and start, end, and execution addresses for the single turbo file that follows. That being the case, TAPClean can acknowledge a turbo file by matching pilot + sync and then “backtrack” a bit to extract such addresses off the relevant CBM file, assuming the latter is healthy.

I had first come up with this strategy a while back when I extended the support for the “Biturbo” format, so this new development reuses the same approach. Eventually I will isolate this functionality and reuse it for all similar scenarios where a turbo file encoding parameters (endianness, short/long/threshold pulse) are not file-specific, i.e. don’t need to be dynamically figured out at scan time, but file-specific details (start/end address, data size, execution address, filename, etc.) are not stored along with the data itself as part of the turbo file’s header.

Once I get a list of the known “Power Load” titles and finish testing with Paul’s help, I might even publish a new release of TAPClean.

Stay tuned!

About luigidifraia

I am a Senior DevOps Engineer so I get to work with the latest technologies and open-source software. However, in my private time I enjoy retro-computing.
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