One turn of the counter should always equate to the same length of tape..
but are you sure?.. the counter is connected to the right capstan with a fixed transmission ratio, once the right reel has a lot of tape on it, because we're at the end of the tape, one turn of it will be wound on a circumference that is far more than the one you have when the reel is empty. Moreover, if the counter takes far more time to switch from one number to the next (and this happens at the end of the tape), given the tape speed is fixed to 5,5 cm/s, I think that in front of the reading head you will see more length of tape passing.. am I incorrect? And this effect depends on how big is the circumference of the tape wound on the reel that in turn depends on the number on the counter and the tape thickness
All tapes are indeed not created equal, I have 2 C90 tapes that come in at 615 and 630 respectively.
Yes, this because the lenght is always approximate, each side of a C90 is usually more than 45mins but by how much depends on the vendor
The thickness of the tapes should generally be the same for the same length tapes Wikipedia: "The C46 and C60 lengths typically are 15–16 um thick, but C90s are 10–11 µm and C120s are just 9 µm thick", so this is not really an issue.
Time ago I was running after *exactly* the same thing you're doing. From the tests you will carry out you will see yourself this is not correct.
Trying to write a graph of the law "speed of counter"/"time" to determine coefficients you will notice that different brands of the same cassette type have different ratios. This is due to the production costs. A thicker tape is of better quality, resists very well to the traction but costs more, low quality tapes tends to have the same very thin tape also on low duration cassettes to save money. A very slight difference in the coefficient will lead to misalignment of the virtual vs real counter of two three turns even after just 30-40 turns.
So, the initial request was for multi-load Turrican where the player is asked to "Rewind to position 30" or such. For this we'd need to have something that mapped fairly accurately to the physical behaviour of the counter.
Is it possible to point me to this version of .TAP? The vast majority of tape games I came across were saying to zero the counter and then rewind to zero or to rewind to the beginning of the tape. I never found a game that was asking to rewind to a specific counter position without giving you any visual clue on where the point it was, also because all the C2N are different, you won't find two different models with the same counter ratio, Commodore ones are different from compantibles, and 1530 is different from 1531, also 1530 has two different kind of counters (the one with white numbers on black drums and the one with white numbers on black drums) then there are magnum ones, unbranded ones, etc.. If they did this with Turrican I think it was very stupid.
On the other hand there is another thing that is missing. In some games user is asked to stop the tape at the end of the loading. In your case this is not possible since if this game is part of a long TAP file SENSE will be kept shorted to ground at all times even if motor goes off at the end of program loading. My suggestion is to add N/C button in series with SENSE line to be sued just in these cases.
I checked also the memory usage of the program and it looks fairly high (at least according to Tapuino IDE) I recompiled the whole thing on Atmel studio and I could save some 6Kb that could be reinvested. The issue is mainly with fatFs version used. If you're not using all the functions you might decide to switch to a lighter version of FF.
By the way, I built one Tapuino and it works good
life has been killer busy for me too! Glad to have you back!
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