As I was thinking of DC2N5-LC I came up with this idea that I could use the filename extractor not just while dumping tapes, but also when it comes to playback TAP files. Why would I want to do that?
Simply put: no IDX file would be required for TAP files with multiple games/software on them as DC2N5-LC would be in a position to scan a file from beginning to end in order to detect the start of a CBM ROM or Turbotape 250 Header.
How cool would that be? 🙂
In fact, IMHO an IDX file is indeed useful in all cases, including multi game collections, but it is really paramount for “zero counter”+”rewind tape to 000” scenarios where the rewind point does not coincide with a CBM ROM or Turbotape 250 Header: I cannot think of a way to automate the discovery of such rewind points.
On the contrary, for tape collections the discovery is rather simple so the use of an IDX file might be advantageous (e.g. when a single title spans multiple CBM files loaded in a sequence and the single bits should not be loaded separately), but not essential.
As an extreme example, the tape version of “Turrican II” for the Commodore 64 used to be tricky to play further once you lost all lives/continues in an upper level. If memory serves me correctly, in the latter scenario you had to zero the counter where you got a “GAME OVER” and rewind the tape drive to a value in the 9 hundreds, e.g. 958. It was a true gamble to assume that people were using the standard C2N for this purpose, and even so, that they were using a particular batch with a counter that was spinning at roughly the same speed as the one used for working out these hard-coded counter values.
Makes you wonder how the hell we survived the ’80s and ’90s 😛