dos33fsprogs/chiptune_debug/NOTES

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note: pausing writes out zeros, doesn't restore previous values
which is noticable
doubling length of writes: still issue
removing rasterbars: still issue
removing volume bars: still issue
remove time update: still issue
remove dead code: still issue
remove title screen: still issue
remove all graphics calls: still issue
remove memory shuffling in back:still issue
remove keyboard: still issue
remove all non-irq code: still issue
remove all text print code still issue
remove multi file (down to 973) still issue
2018-06-13 15:17:01 +00:00
remove dos33 code still issue
remove lz4 code still issue
remove interrupt driven still issue!?
play at 25Hz still issue
50Hz,inline, no play 11,12,13 still issue
also turn off A/B freq still issue
also turn off noise/Aamp/Bamp still issue
2018-06-13 15:17:01 +00:00
move to single output routine still issue
always volume 12 still issue
2018-06-13 16:17:10 +00:00
fix clear accidentally wr r14 still issue
generate single tone FINE!!!
only play first 16 notes still issue
only change C-fine value still issue
only write val, not address still issue
use handshake-free porta/6522 still issue
Look at interrupt registers on 6522
Emulator: IFR=$C0 IER=$80, Actual: IFR=$C0,IER=$C0
For 6552-2 it is $00/$80 on both
Tried soldering so pin 18 (PB1) always high
still issue
Tried reading back value from AY-3-8910, always match.
Channel A and B now have glitches offset by 320ms?
Interrupt happens at 50Hz=20ms? 16 samples??!??
NOTE: Applewin Bugs
+ Doesn't support reading back AY-3-8910 (Always returns
last written value?)
+ IER doesn't show Timer1 enabled? (returns 80 rather than C0)
Now glitch happens exactly every 640ms (32 50Hz interrupts) when playing
pattern of 8 notes repeatedly
Remove other cards from machine to see if power issue
still issue
When down to writing 4 values,
$51,$3c,$32,$50, issue seems to often hit on
the 51->3C transition
Down to two values, still only hit on the 51->3c transition.
Sometimes everytime, sometimes every Xth time.
$51 by itself = fine
$3c by itself = fine
50/3c and 50/32 also have issues, but not quite the same
(Some, audio fading instead of glitch?)
2018-06-13 16:17:10 +00:00