Thomas Harte
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180c3df2d4
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Calling it 'number theory' probably isn't accurate but extracted the CRC stuff and started using it for [M]FM encoding.
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2016-09-18 18:33:26 -04:00 |
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Thomas Harte
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55a7418cbf
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Parameterised to perform FM and MFM encodings, at least subject to CRCs still being missing.
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2016-09-18 17:16:20 -04:00 |
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Thomas Harte
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22eed60d2b
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Started sketching out basic MFM track encoding. Which possibly even means that the shifters don't need to be public?
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2016-09-18 16:53:21 -04:00 |
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Thomas Harte
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0089c830c6
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This possibly correctly encapsultes the lowest level of FM and MFM rules.
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2016-09-18 14:17:06 -04:00 |
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Thomas Harte
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bcf91de7e9
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Declared support for the Acorn disk files, started hammering out an encoder.
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2016-09-18 13:35:54 -04:00 |
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Thomas Harte
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79ef38b123
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Attempted to use the new get_cycles_until_next_event method to take some repetition outside of the PLL and drive event loops.
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2016-09-17 22:02:38 -04:00 |
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Thomas Harte
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9d6dcb80a7
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Started work on a GCR parser and the helper functions that lie behind that.
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2016-09-13 21:53:36 -04:00 |
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Thomas Harte
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82c8459055
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Minor tidying of namespace usage declarations.
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2016-08-27 17:18:12 -04:00 |
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Thomas Harte
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56c0d70c1f
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Gave disks their own namespace.
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2016-08-27 17:15:09 -04:00 |
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Thomas Harte
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9d76cd9b60
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Removed dead instance storage.
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2016-08-04 21:41:12 -04:00 |
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Thomas Harte
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3e90b85ff8
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Made an attempt to insert proper conversions to/from rotational speed. The Time class is now really turning into a full-on quotient. Might need refactoring.
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2016-08-04 21:36:39 -04:00 |
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Thomas Harte
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e57ab1025d
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Fixed location calculation, up to a point.
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2016-08-03 22:33:00 -04:00 |
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Thomas Harte
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9af9b28baf
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Made very first attempt at closing the loop on this. But it's time for work.
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2016-08-03 08:16:23 -04:00 |
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Thomas Harte
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e15241dc3c
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Added ability to query how long since the new interval was set to the timed event loop. Discovered that LCM will returning the net effect of the common factors only. Otherwise continued iterating towards time preservation.
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2016-08-03 07:49:00 -04:00 |
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Thomas Harte
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a3a3486f54
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Okay, it's becoming more apparent where the (very mild) complexity will be here. But started moving towards retaining rotation between tracks.
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2016-08-03 07:33:26 -04:00 |
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Thomas Harte
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21f1fa37a4
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Fixed Time addition, added accumulation of distance into track into the disk drive, added a short circuit for LCM.
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2016-08-03 07:26:05 -04:00 |
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Thomas Harte
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30f8b6baa4
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Made an attempt to add the necessary extension to Track, with a concrete implementation in PCMTrack, to support time-based seeking, the intended mechanism for not magically spinning the disk back to the index hole upon every head step.
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2016-08-03 06:59:45 -04:00 |
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Thomas Harte
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d832e5e10d
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Reduced 1540 PLL to running at 4Mhz. Which is possibly correct (?) Made minor change to avoid divide if possible.
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2016-08-02 21:28:50 -04:00 |
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Thomas Harte
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bc10b3ee9a
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It appears the problem is as simple as sectors being counted from zero.
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2016-08-01 10:08:38 -04:00 |
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Thomas Harte
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f5e4ea3351
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Some minor tidying, lots more of the caveman stuff as I try to determine what I'm doing wrong.
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2016-08-01 09:43:08 -04:00 |
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Thomas Harte
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a00f9adba3
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Made a first attempt at D64 support. Made an error somewhere but this should be 90% of it.
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2016-08-01 08:41:16 -04:00 |
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Thomas Harte
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58297f1baf
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Performed the basic metadata and routing for opening D64 files. Realised that I wasn't actually necessarily catching exceptions properly for all file opens, and fixed.
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2016-08-01 07:09:15 -04:00 |
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Thomas Harte
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2799a87218
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Reduced possibility of overflow on LCM, improved commenting widely, removed one stale piece of G64 bootstrapping caveman stuff.
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2016-08-01 06:04:55 -04:00 |
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Thomas Harte
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198fbbedc7
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Reeled back all appropriate pieces of caveman debugging.
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2016-07-31 13:42:34 -04:00 |
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Thomas Harte
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2332f72875
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Formalised clock-rate multiplication within disk drives, discovered that the stepper didn't have ideal behaviour for my timed event loop and hence nailed down the semantics a ilttle more.
(obiter: the 1540 now appears to discern the correct sequence of bits. Framing is off in my test printfs but that's neither here nor there).
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2016-07-31 13:32:30 -04:00 |
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Thomas Harte
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6ee784a893
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Increased logging; discovered I was packing events together too closely. Now getting some zeros.
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2016-07-30 04:30:55 -04:00 |
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Thomas Harte
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fead524eb5
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Attempted to give the PLL a litte extra leeway, and fixed PCMTrack length test.
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2016-07-29 18:52:50 -04:00 |
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Thomas Harte
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8f62211f5e
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Wired up the 1540 as a PLL delegate. Which prima facie means it should start receiving a bit stream. Except that I clearly have something in the timing way off — either my flux transitions are far too short or I need to significantly increase the clock rate on the PLL.
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2016-07-29 12:08:18 -04:00 |
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Thomas Harte
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89a1881fef
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Started turning the 1540 into an actual disk drive.
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2016-07-29 11:03:09 -04:00 |
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Thomas Harte
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6532b3a8c8
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Filled in a calculation of clocks per bit that'll do.
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2016-07-29 07:51:07 -04:00 |
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Thomas Harte
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f984de42a3
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Took some small steps towards having a disk drive that at least can select a track and pump relevant events into a PLL.
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2016-07-29 07:31:02 -04:00 |
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Thomas Harte
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e55db0cfe8
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Made an attempt to eliminate creeping tape processing accuracy misses, which implied factoring out the GCM and LCD functions, which I then felt didn't really amount to signal processing.
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2016-07-29 05:19:01 -04:00 |
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Thomas Harte
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5c1614ce7b
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Attempted to simplify, very slightly.
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2016-07-28 14:35:39 -04:00 |
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Thomas Harte
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015cea494d
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Switched to a much-more straightforward PLL. I think I'm just fiddling now rather than moving forwards. Probably time to move on?
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2016-07-28 11:32:14 -04:00 |
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Thomas Harte
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e061e849d4
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Had a second bash at the PLL. Probably I should read some of the literature.
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2016-07-27 16:24:24 -04:00 |
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Thomas Harte
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63f39608a6
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Added just enough to get back to a working build.
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2016-07-15 20:35:19 -04:00 |
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Thomas Harte
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165dbd9651
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Started fleshing this out a bit. Hopefully.
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2016-07-15 08:28:34 -04:00 |
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Thomas Harte
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0aa90b943b
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Switched to specifying bit length as a quotient for the purposes of a PCMSegment and verified that I had the logic for picking a Commodore time zone backwards: bigger numbers are faster, not slower.
Started sketching out a DiskDrive class.
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2016-07-15 06:51:11 -04:00 |
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Thomas Harte
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6afd619791
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Eliminated floating point arithmetic.
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2016-07-14 19:47:00 -04:00 |
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Thomas Harte
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6b4fec37ff
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Moved down to a single divide.
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2016-07-14 19:45:08 -04:00 |
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Thomas Harte
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481475a0f4
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Switched to a full-on linear regression. Which causes the current tests to pass.
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2016-07-14 19:42:01 -04:00 |
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Thomas Harte
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6d6b26b99f
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Actually made things worse.
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2016-07-14 07:32:27 -04:00 |
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Thomas Harte
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d8d3464c56
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Made a quick-hack attempt at PLL synchronisation. Which doesn't work.
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2016-07-14 07:31:23 -04:00 |
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Thomas Harte
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d1fe07f14d
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Added test of perfect DPLL input timing.
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2016-07-12 21:42:23 -04:00 |
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Thomas Harte
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94db45456e
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Started sketching out the basic form here, albeit that it doesn't yet do _the only thing it advertises itself as useful for_.
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2016-07-12 20:23:56 -04:00 |
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Thomas Harte
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75d95c0bc0
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Sketched out an interface for a digial PLL. Not persuaded yet. Baby steps.
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2016-07-11 22:12:58 -04:00 |
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Thomas Harte
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1e9eedc314
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Factored out the PCM track since it's going to be a useful construct for almost every file format. Documented it a little better.
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2016-07-10 18:36:52 -04:00 |
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Thomas Harte
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66895d3ac7
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Actually, I think this is the correct conversion from received speed to clock rate. It'll become obvious if it's not when I get back to working on the 1541 itself.
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2016-07-10 18:24:12 -04:00 |
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Thomas Harte
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19ee430d4a
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Made an effort to support zoned tracks, at least.
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2016-07-10 18:07:53 -04:00 |
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Thomas Harte
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6593caca93
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Switched to a probably more helpful way around of expecting bits in bytes.
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2016-07-10 16:21:52 -04:00 |
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Thomas Harte
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845a00ccef
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Attempted via linear search to implement PCMTrack::get_next_event.
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2016-07-10 16:17:25 -04:00 |
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Thomas Harte
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f9510c1b67
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Put sufficiently much of PCMTrack into place to get to a stored list of segments, having determined a common clock rate between them and therefore a complete track length.
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2016-07-10 16:10:05 -04:00 |
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Thomas Harte
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4ae9f5ad5d
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Added preliminaries of reading the speed zone information.
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2016-07-10 13:42:45 -04:00 |
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Thomas Harte
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8ae78ba4e0
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Fixed signature check and fseek parameter order.
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2016-07-10 13:32:59 -04:00 |
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Thomas Harte
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ff49857f5c
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Started sketching out support for the G64 file format.
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2016-07-10 10:17:53 -04:00 |
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Thomas Harte
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9e3d6b762b
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Sketched out the generic interface for a disk, documenting it and the tape interface while I'm here.
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2016-07-10 08:54:39 -04:00 |
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