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I've always thought that too - when I had just a 6100 and I took it all apart, I discovered that the speaker was right under the floppy drive. And the best place to get really strong magnets is from INSIDE of hard drives. Go figure. Floppy drives have fairly powerful magnets in their motors...

Underware was my FAVORITE screen saver program and it supported AD modules too. I'm not sure why they named it that other than just to be silly. There was even a module that had Bill Gates stuck inside your screen that bounced around and periodically slammed into the glass.

If you start up from the floppy, enable RAM disk, and restart again from the floppy to mount the RAM disk, you are then free to eject the startup floppy even with the RAM disk still empty and swap as many additional non-startup floppies as necessary to get everything you need into the RAM disk...

"Super ResEdit" has a built-in 68k disassembler almost identical to Resorcerer's. It only disassembles though. This is freeware as far as I'm aware and can be found easily with Google. I'm not sure how good of a disassembler it is though. To use the disassembler on a dump of hex data, create...

The 7.5 NAD's system file and the normal 7.5 system file are different animals entirely in the resource fork. I didn't even look at the data fork. If you can trim a normal system down enough, that could be the best solution, but it seems like a long shot to start swapping resources around from...

I compared the System 7.5 Disk Tools to the System 7.5 Network Access. The network access system file is the same as the disk tools system file, with several extra resources: 'AINI' (all) 'atlk' (all) 'drvr' (all) 'DRVR' 9, 10, 40, 126, 127 'ecf2' (all) 'ecfg' (all) 'enet' (all) 'ICN#'...

Here are the 3 wave types graphed in Excel - this is where I experimented to find the right values. All three are given the same first nibble, then the rest of the nibbles are all 0. So this is basically a unit step response for all 3 wave types. Maybe the blue wave (type 1) starts 1 sample...

Do you mean Power Mac / Performa 5xxx? 5500 is considerably better than some of the lower numbered 5xxx Macs.

There are some guys here that probably know a lot about old hardware. I have an appreciation for it but I wasn't around for deep electronic stuff back then - I'm in my mid twenties. I posted the code in color-coded form here, along with a little blurb/summary about the whole thing...

I thought I'd throw together a little montage of the progression of this decompressor, from when we started until now. https://sites.google.com/site/benboldt/files/startup_evolution.aif

Well, if I was a good engineer, I would know when to stop. :p But hey, this isn't work, it's for fun, so too bad. ;) https://sites.google.com/site/benboldt/files/Q700DataOut7.aif I can no longer hear any problems in the sound with my ears. Some of the differences are probably because...

Actually it improved it more than I thought! I keep track of the "delta" variable better when switching between packet types now. I still don't know what the HECK is going on in the 5th packet though.

I've cleaned up the code and it actually ended up making an extremely slight improvement to the sound. But the code is simpler now. In the image the I posted that shows each packet with magenta lines - it looks pretty much like those magenta lines are supposed to move two spaces to the left...

Most of the remaining issues come from where one packet hands off to the next, even if the packet type remains the same from one to the next. I think that you have to partially calculate the next state in the current state.

I have it to the point where it sounds good now, but it is not perfect by any means when you start comparing the waveform to an actual recording. It's in the very nature of this integration-type decompression to propagate the slightest error into something huge. I believe that it could be...

I have plotted out the beginning of the normal startup chime. The dark line is the one that went through my program, the lighter line is an audio recording of the Quadra 700 playing it, magenta stripes are the first nibble in a packet, green stripes are the other nibbles, and the number printed...

I just realized that this compressed sound is much higher quality than the non-compressed version. decompressing this sound results in 16-bit audio whereas the non-compressed one is only 8-bit. Even where this converter is at right now, the 16-bit one sounds better than the 8-bit, except for...

It's ALMOST perfect now! :D https://sites.google.com/site/benboldt/files/Q700DataOut5.aif #include #include #include using namespace std; int main(int argc, char *argv[]) { FILE *f = fopen("Q700RawSoundData2", "rb"); FILE *w = fopen("Q700DataOut", "wb"); int16_t cosine_wave[21] =...

I'm trying to think in terms of piecewise functions - it seems like a chip like this would do simple calculations based on a very short history of the sound, and won't keep track of the sound very far outside of the current position of the sound wave and the current nibble. So for example...

The type 2 curve closely resembles a primitive dissonance curve: y = x * Exp(-x) If you plot, use x range 0 - 1 y range 0 - 0.4