ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
<Sarayan>
Foone or whitequark, may I do a floppy-related request?
<Sarayan>
It's all about the write-protect line. What is its level when there's no floppy in the drive, and what's the waveform when you put a write-protected or non-write-protected disk in the drive then remove it?
<Sarayan>
it's not documented anywhere that I can find
<Foone>
the FDC37c78 datasheet says it's active-low.
<Sarayan>
that doesn't say a thing about what it does outside of the normal "I have a floppy settled in the drive" situation
<Sarayan>
that's what I'm missing
<Foone>
are you trying to see what happens when you put the disk in? like, toes it temporarily go up and down?
<Sarayan>
yes
<Sarayan>
and also what the state is when there's no floppy in
<Sarayan>
a number of systems, including the atari st, try to use that to detect disk change
<Foone>
that might not be defined. I think some of them only turn on the LED for the sensor once the disk has been put in. not to mention the weird laptop ones which don't use optical sensors at all
<Foone>
so I think it might vary from drive to drive
<Sarayan>
it could, but I don't even have the information for one drive :-)
<Sarayan>
otoh, if there's someone that can actually compare drives, that's you :-)
<Foone>
yeh. I'll not in the position to do it right now but I can try to check it out tomorrow
<Sarayan>
very cool
<Sarayan>
there's no hurry, but have the correct behaviour(s) in mame would be rather useful
<Sarayan>
and since it seems that w.r.t floppies I'm in mame what you are in the real world... :-)
<whitequark>
Sarayan: from what i recall, Foone is correct
<Sarayan>
as in the led is only on when a floppy is detected?
<Sarayan>
tbh, I'm not 100% convinced of the active low either, because I'm pretty sure the floppy drive associated to the apple diskii is active-high
<Foone>
well the apple II disk drive is a whole different thing. it's way off in its own strange field
<Sarayan>
yes, yes it is
<Sarayan>
you can force the wp line to 1 by putting 1 on the phase1 line
<Sarayan>
they use that to detect the presence of the floppy drive
<ZrX_NoMs>
disk change signal on 3.5" drives also requires a step to update the signal
<Sarayan>
st for instance does not have a connected dskchg signal
<Sarayan>
they rely on the wp behaviour (and no, it's not reliable, surprise surprise)
<Sarayan>
if you have a running st and you look closely at the disk selected led you'll notice it's blinking, that when the vblank handler tests the wp pin from time to time
<ZrX_NoMs>
got a drive in the amiga which is very very odd about diskchange and someone suspected it's from atari.
Sarayan has quit [Quit: bbl, hard drive fun]
<andlabs>
hard drives are fun
Sarayan has joined ##yamahasynths
<ZrX_NoMs>
Until they break down.
<cr1901_modern>
I remember my first click of death