mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-12-26 11:30:12 +00:00
95 lines
2.7 KiB
Plaintext
95 lines
2.7 KiB
Plaintext
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
|
|
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
|
|
move to single output routine still issue
|
|
always volume 12 still issue
|
|
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?)
|
|
|
|
|
|
Got new AY-3-8913 chips
|
|
Tried looking at the timings.
|
|
8913 timings are actually worse in some cases (especially writes)
|
|
than 8910, though still in the low us range so we shouldn't be
|
|
hitting it?
|
|
|
|
The programming manual and timing diagrams hint that you can flip
|
|
the address_latch / address ordering when writing. This does
|
|
work on real hardware but not in any of the emulators.
|
|
|
|
Have a new test, chiptune_smallest:
|
|
+ No IRQ, plain busy wait at 20ms
|
|
+ No lookups, hardcode the $51 to $3c transition
|
|
|
|
Still shows the glitch, actually very quickly.
|
|
Changes made to test this:
|
|
+ Try increasing the WAIT delay from 85 to 120
|
|
(still an issue)
|
|
|