Post ABAidO2OhJuu2hKQqm by scruss@mastodon.social
(DIR) More posts by scruss@mastodon.social
(DIR) Post #ABAAvJsMf0PqTw6ejg by natalie@nya.social
2021-09-08T20:45:23.652Z
15 likes, 13 repeats
Preliminary dump of the voice data from a McDonnell-Douglas H05A0035-10 Central Aural Warning System. I believe first flown on the DC-9.Voice data was stored on three 256Kx8 EPROMs. I traced out a schematic of the voice board and dumped them in-circuit, so there was no need to try and desolder the chips from the heavily conformal coated multilayer board.
(DIR) Post #ABAB44lkCElGEeBXIu by natalie@nya.social
2021-09-08T20:46:58.256Z
3 likes, 5 repeats
Some more detailed shots of this thing. As always with avionics, beautiful construction, both electrically and mechanically.
(DIR) Post #ABABAGeavFCypfnFTM by natalie@nya.social
2021-09-08T20:48:05.659Z
4 likes, 3 repeats
Further closeups on the boards.
(DIR) Post #ABABdnHsfbzIRSFSm8 by natalie@nya.social
2021-09-08T20:53:25.583Z
2 likes, 2 repeats
I'm calling the voice data a preliminary dump because I don't entirely understand the encoding here yet. It's not straight PCM, and it's also not any common compressed audio formats (tried various A/DPCM algorithms, CVSD, u-law, etc)... I've gotten the best results so far by treating everything like signed 4-bit PCM and doing a little massaging of the values. But the waveform shows some inversions on peaks (and it's generally very crunchy and noisy) which leads me to think there's more to the story here. This dates to the late 1970s so it can't be anything too fancy.It would be possible to look at the code to see what it's doing, but only one of the program ROMs is socketed so that's the only one I've dumped so far. And the CPU is a CDP1802 COSMAC which is an architecture I've never worked with before...Dumped ROMs attached if anyone wants to take a look 👀
(DIR) Post #ABACJduXvCE3WYHyBE by ieure@mastodon.social
2021-09-08T21:00:49Z
1 likes, 0 repeats
@natalie This is so fucking cool. Thanks for sharing.
(DIR) Post #ABACmM9J2Tg2pmstJQ by natalie@nya.social
2021-09-08T21:06:10.672Z
0 likes, 0 repeats
Also here is a dump of a GPWS I tore down a year or two ago. This one was easy, 8khz ulaw with a header.Still have another GPWS I need to liberate the ROMs from as well... Once again, a ton of layers and very thick conformal coating, but also no easy way to get at the bus, so the chips will have to come out.
(DIR) Post #ABACmxoizRnDexXzVY by techfury@snack.social
2021-09-08T21:05:59.131540Z
1 likes, 0 repeats
@natalie I'm pretty sure this is a DC-9/MD-80 part because the samples include "left" and "right", as in "fire left engine", whereas the DC-10/MD-11 would have had "one", "two", and "three" because 3 engines.
(DIR) Post #ABACqrZAAn8ZQm7yqm by natalie@nya.social
2021-09-08T21:06:59.863Z
1 likes, 0 repeats
@techfury@snack.social Makes sense, I compared to an MD-11 recording on YouTube and it's definitely the same voice but a few different phrases.
(DIR) Post #ABAD2rc3pDWj3DCney by natalie@nya.social
2021-09-08T21:09:09.631Z
4 likes, 2 repeats
Also here is a dump of a GPWS I tore down a year or two ago. This one was easy, 8khz ulaw with a header. Interesting CPU-less architecture in this one, it's run by three FPGAs which I am guessing replaced a bunch of discrete logic in prior models.Still have another GPWS I need to liberate the ROMs from as well... Once again, a ton of layers and very thick conformal coating, but also no easy way to get at the bus, so the chips will have to come out.
(DIR) Post #ABADSS4FQORnLuahmq by ieure@mastodon.social
2021-09-08T21:04:06Z
1 likes, 0 repeats
@natalie 1802 is neat. I keep thinking I should build a COSMAC ELF.
(DIR) Post #ABAEEVTQ43eToeHN6u by techfury@snack.social
2021-09-08T21:18:25.619272Z
1 likes, 0 repeats
@natalie have you located which chip is the DAC? that might shed some light on the sample format...
(DIR) Post #ABAEEW1o0D9pXIMphw by natalie@nya.social
2021-09-08T21:22:28.095Z
0 likes, 0 repeats
@techfury@snack.social It might be an AD7524 but I could be wrong, that may be used for something else. Maybe there's a latch and R-2R resistor ladder buried in one of these boards...
(DIR) Post #ABAFiJ8IbwqQBSAsRE by techfury@snack.social
2021-09-08T21:30:17.197819Z
0 likes, 0 repeats
@natalie aha! I didn't catch the AD7524, but I think there's some Interesting Stuff on the board that says A1 at the top and C in the bottom right corner. a few things I noticed with that one: CD4515 4 bit latching decoder right by the cryptic "304504" chip, and two CD4067 analog muxes. my inkling is that the CD4067s have *something* to do with the audio path, because why else would you specifically use an analog switching part? maybe the 304504 is the DAC...
(DIR) Post #ABAFiJb0tBoTcVboC8 by natalie@nya.social
2021-09-08T21:39:03.448Z
0 likes, 0 repeats
@techfury@snack.social hm, I was thinking that was more likely for input from the plane and all the diodes are clamping voltage spikes, but maybe. Wish it was easier to trace this thing out, my usual technique of bright-ass light shining through the board is useless here, I think the only option really is a few hours with a continuity tester
(DIR) Post #ABAFurAfsp1DE7Gl9c by Lofenyy@mastodon.technology
2021-09-08T21:37:28Z
0 likes, 0 repeats
@natalie Spooky, I love it!
(DIR) Post #ABAG1u8fFS4ISQgpBw by ignaloidas@not.acu.lt
2021-09-08T21:32:38.260Z
0 likes, 0 repeats
@natalie@nya.social Haven't looked at the data at all, could it be PDM? Would explain a bit why it somewhat works as a 4-bit PCM, and PDM is (at least now) quite common in embedded.
(DIR) Post #ABAG1ucnRQAfxsmt9s by natalie@nya.social
2021-09-08T21:42:34.612Z
0 likes, 0 repeats
@ignaloidas@not.acu.lt idk but it's worth a look. it seems like silent periods are usually repeating 0x99 which is kind of weird
(DIR) Post #ABAfjfqn5EFdAACprU by nick@social.kaitaia.life
2021-09-09T02:30:30.266411Z
0 likes, 0 repeats
@natalie that looks like fun! You've got some MAD skillz to do this. Very interesting 👍😊
(DIR) Post #ABAidO2OhJuu2hKQqm by scruss@mastodon.social
2021-09-09T02:55:36Z
0 likes, 0 repeats
@natalie yeah, I remember this one: terrain ... Terrain ... pull up ... PULL UP!
(DIR) Post #ABBB73I6EveHyhxBDM by natalie@nya.social
2021-09-09T08:22:13.007Z
3 likes, 5 repeats
Since I was in the right frame of mind to do it, I finished removing and dumping the ROMs from another piece of avionics I had laying around - an AlliedSignal Mk VII Warning Computer 965-0876-040.These were used with a NEC uPD7759 speech chip in master mode, so it took some work to get usable audio out of them... ended up writing a custom ADPCM decoder based on the MAME sources.Raw dumps and decoded audio are also attached. There is 3mbit worth of data but the speech chip can only address 1mbit at a time, so the host CPU is bank switching what the chip can see. As a result the audio is split into three different banks.
(DIR) Post #ABBBDTJcOVLeQfj0q0 by natalie@nya.social
2021-09-09T08:23:22.807Z
0 likes, 0 repeats
(Mastodon doesn't show the zip file, view the post from my instance if you want it)
(DIR) Post #ABBBPnMtfDvU658Q1A by katnjiapus@toot.site
2021-09-09T08:24:39Z
0 likes, 0 repeats
@natalie Does on my end. Could be a glitch thing ofc
(DIR) Post #ABBBPny7QphTxWY92G by natalie@nya.social
2021-09-09T08:25:35.367Z
0 likes, 0 repeats
@katnjiapus@toot.site but it doesn't embed the video! curious. on the instance i looked from, it showed the video but the zip was nowhere to be found
(DIR) Post #ABBBTqnqprcvuMfzNY by bhtooefr@snack.social
2021-09-09T08:25:28.774992Z
1 likes, 0 repeats
@natalie did they actually get some other voice actor just to scream the “pull up, PULL UP!” warning into the mic
(DIR) Post #ABBBTrKorHzxYc6JlY by natalie@nya.social
2021-09-09T08:26:20.117Z
1 likes, 0 repeats
@bhtooefr@snack.social lol. on first listen the second version actually scared the hell out of me, it was a lot more aggressive than i was expecting
(DIR) Post #ABBCzoZmka5CDqu1J2 by Skirmisher@cybre.space
2021-09-09T08:28:01Z
1 likes, 0 repeats
@natalie jeez they took a different angle with "PULL UP" on this one
(DIR) Post #ABBCzp3uwYBZjJ05Gy by jk@mastodon.social
2021-09-09T08:31:05Z
0 likes, 0 repeats
@Skirmisher @natalie extremely good UX design imo
(DIR) Post #ABBCzpcIshgvRx5Xs0 by natalie@nya.social
2021-09-09T08:43:17.977Z
0 likes, 0 repeats
@jk@mastodon.social @Skirmisher@cybre.space have to wonder if it was actually used. i've heard pull up alerts with increasing aggression before but the second one is a bit over the top
(DIR) Post #ABBFQESTLNZxvpCrgG by natalie@nya.social
2021-09-09T09:10:30.368Z
1 likes, 1 repeats
btw it took some ridiculousness to get this data. As I mentioned upthread it's a multilayer board, with big thicc power planes, and a ton of conformal coating. I don't have a proper vacuum desoldering gun, and even if I did, I wouldn't want to clog it with conformal coating (since it dissolves with acetone but you'll never manage to get it all).So the first chip was removed by cutting it off the board with wire cutters. This was an awful idea and resulted in the complete loss of probably 10+ pins. What I ended up doing was securing it on top of some random IC sockets and then running thin wires to what remained of the pins... which in many cases was just a bit of metal flush with the side of the package.For the second one I decided to dremel it out. This worked a lot better, since while all the pins were chopped short, it was very easy to solder some pinheaders to the stubs and drop it right in the EPROM programmer. On that one there was a bit of a scare when pin 30 was showing as open circuit despite having a very solid connection, but that was because I was trying to dump as a 27C020 rather than 27C010 - on the '020 that's A17, but on the '010 it's NC! WoopsThis whole process was definitely a bit brutal but I made the judgement call that it's worth potentially rendering the unit inoperable for the benefit of preserving the most important data from it. I'm not the only one who has run into this issue either, another person on youtube has a few undumped GPWSes and other stuff because it's such a pain to get the chips out
(DIR) Post #ABBcC7eu7pTdjdGKjw by mrsaturday@shitposter.club
2021-09-09T13:25:41.406313Z
3 likes, 2 repeats
@natalie I worked for an electronics recycler with Northrop Grumman as a client. The stuff they sent in was pretty cool, I wish I would have taken pictures. We'd occasionally get tapes that would say "missile data" and stuff like that on there.They sent us one of these, too. Not sure why this stood out. It had to weigh 80 pounds.
(DIR) Post #ABBccJ2mPzvwZfuome by Moon@shitposter.club
2021-09-09T13:30:24.764535Z
0 likes, 0 repeats
@mrsaturday @natalie did you get to keep stuff
(DIR) Post #ABBcg4TQX2h2XnAtAO by mrsaturday@shitposter.club
2021-09-09T13:31:06.141291Z
0 likes, 0 repeats
@Moon @natalie "No"In fact, my wife's laptop did not come from there
(DIR) Post #ABBsYhIXtk33uEah9c by oct2pus@jade.moe
2021-09-09T10:23:01Z
0 likes, 0 repeats
@natalie i do appreciate have a second version of pull up thats significantly more forceful and panicked. even the computer is freaking out.
(DIR) Post #ABBsda5E9MQqyfgpxg by abortretryfail@mastodon.social
2021-09-09T10:33:00Z
0 likes, 0 repeats
@natalie Ever used those hollow stainless steel desoldering needles? They're perfect for this kind of stuff.
(DIR) Post #ABBsdab8Ejx8ZccJgu by natalie@nya.social
2021-09-09T16:29:54.405Z
0 likes, 0 repeats
@abortretryfail@mastodon.social I didn't even know these were a thing. this looks super useful
(DIR) Post #ABBt9ERk8AEF8fJWS0 by thor@pl.thj.no
2021-09-09T16:35:36.951628Z
1 likes, 0 repeats
@mrsaturday @natalie spectrum analysers cost a fortune
(DIR) Post #ABBvRYdY0AjmsYhXvc by ieure@mastodon.social
2021-09-09T16:44:21Z
1 likes, 0 repeats
@mrsaturday @natalie I live near the Tektronix HQ and (pre-pandemic) would go dig through their recycle/salvage store. I got so much great stuff from there.Lots of Tek scopes, probably the best was a TD2014. One channel didn't work, because the BNC connector was broken. Several early digital CRT scopes, too, some analogs. 3-4 Data I/O UniSite programmers, TPGs, all kinds of cool stuff.One of the better finds was a Tek 760A, they cost hundreds on eBay.
(DIR) Post #ABBvd4VlpilMvCYPw0 by mrsaturday@shitposter.club
2021-09-09T17:03:27.334495Z
0 likes, 0 repeats
@ieure @natalie We didn't know what it was, but it looked old, so we recycled it. Later on I found out that spectrum analyzers like that are four digits. Whoops.
(DIR) Post #ABCISsFCswqyvRuf2G by bhtooefr@snack.social
2021-09-09T21:18:59.042267Z
1 likes, 2 repeats
@natalie also also: “Don’t.”
(DIR) Post #ADLlb2f1jsWEULpOTY by natalie@nya.social
2021-11-13T06:42:20.170Z
1 likes, 0 repeats
Two new sets of avionics voice data posted. These weren't dumped by me, they're actually from software updates on the manufacturer's site. I don't know anything about the overall format but I found and extracted the audio.https://www.youtube.com/watch?v=qDwX6RhsBikhttps://www.youtube.com/watch?v=lt_sQLpiL70
(DIR) Post #ADW1UnEAgkoMHlnaRU by natalie@nya.social
2021-11-18T05:27:35.947Z
0 likes, 1 repeats
Updating this thread, I mentioned the CAWS audio I posted before could only be considered preliminary, because I hadn't fully figured out the encoding it uses, so the quality was not as good as it should be.I ended up tracing out some of the power supply circuit so I could power up the unit and get good quality recordings directly from the output. These are "assembled" the way they should be (instead of individual words in random order) and of course are decoded properly.