gwEm - Flash Of The Rom (AtariST YM2149 register dump analyzser)
Channel: Gunstick
Date: 17/02/2021

Register dump of 'Flash of the ROM' by gwEm. Winner of the STNICCC 2015 music competition.
Used code: https://github.com/Gunstick/sc68-visual (still written in awk)
For info, here is a little bit of what you see on screen:

Details of the columns. 
Left side: 
before the # is the minimal register change produced by "sc68 --ym-clean-dump"
VBL: main player routine call counter. In this case around 50Hz
YMtime: clock cycle of the soundchip at 2Mhz
FreqA - FreqC: frequencies of the 2 channels
N: frequency of the noise generator
Mx: mixer register of the YM
VA - VC: volume of the 3 channels
FreqE: frequency of the envelope
Sh: shape of the envelope

Right side (after the # mark)
delta: indicates the delay between changes. (40064 is 50Hz).
Channel A - Channel C
Then are shown the 3 channels as FFF(n#o)NNtv
FFF is the frequency in hex
n#o is the note and octave
NN is the noise frequency (or -- if not active)
t is the type of output 
t= (blank) no output
t=. only tone output
t='  only noise output
t=! tone and noise output.
v is the volume, from 0-F. If the envelope is used then this is replaced by the actual shape, frequency and note of the envelope.
The volume level is also as a line style VU meter

At the right border is again shown the general Noise, envelope frequency and shape
Last is the number of registers which have been updated per VBL

If there is a ~ before the envelope shape, this indicates that the shape register R13 is written, and restarts the envelope.



The Hz figure is dynamically calculated, and for usual chiptunes does not change. It indicated how many times the main tracker routine is called.


The bottom of the screen contains the same data, but only if timer effects are used. Timer effects are fast updates of the YM, so for every VBL there can be a couple or up to over 40 lines, the dots at the bottom indicate how many lines are not shown.
The program makes a guess which timer effects are currently used.
Detected effects: 
SID pwm (using tone + volume toggling)
SID shortwave (using tone + multiple volume levels)
pwm (pure pwm like known from the C64, a.k.a. ZID)
digit/short wave (only using volume to create sound)
syncbuzz (fast triggering of the envelope shape)