[X] My Assistant

This is an idea I've been mulling over making a thread for for a while now.

I don't want to call it a "Q&A thread" because that sort of implies the "answer the question posted above you." That'd die fast from a ridiculous question.

Anyway, if you're trying to do something and can't figure out how to do it, whether it be computer/digital, electrical, physical, or whatever else, try explaining the situation and see if any of us want to take a try at tackling it. There's a chance no one will, of course, but there's no harm in trying.

I'd like to try to answer as many as I can for a few days at least.

Example good questions:
"How do I extract a flash SWF from this old EXE file?"
"How do I extract images from a flash SWF?"
"How do people translate visual novels that use [engine]?"
"What engine does my visual novel use?"
"Does my car need a new transmission?"
"How does emulation actually work?"
"How do plasma screens actually work?"
"Why is my volume dial scratchy on my game boy?"
"Can anyone explain what this circuit does?"
"How do I compile this program?"
"Why did my GPU stop working?"

Example bad questions:
"Can someone teach me how to hack?"
"Can someone help me find a keygen for [program]?"

This post has been edited by dragontamer8740: Jul 6 2022, 03:27

I like the idea but I feel like it'd kill at least 60% of the posting in the tech thoughts threads.

that said, im still working on my shoddy ethernet iot board, which will have an enc28j60 as ethernet interface. and I'm wondering how much I can slack on EMI filtering. I'm considering the following:
- ignore the circuitry of the centertaps on incoming side, those are going directly to my poe circuitry
- the ferrite bead would be an annoying space consuming component and I dont care for sourcing, leave that out
- transformers are all going to only have a center tap on the incoming side


question here being, is this going to matter? keeping in mind this will be very low speed or traffic.
if it does matter, how much would it matter and for what cases?
my knowledge of filtering ends at slapping some decoupling caps around mcus

This post has been edited by cate_chan: May 5 2022, 19:58

I like the idea but I feel like it'd kill at least 60% of the posting in the tech thoughts threads.

I was weighing against that, too... but I think actively inviting people to ask questions might garner more activity on this board, maybe.

that said, im still working on my shoddy ethernet iot board, which will have an enc28j60 as ethernet interface. and I'm wondering how much I can slack on EMI filtering. I'm considering the following:
- ignore the circuitry of the centertaps on incoming side, those are going directly to my poe circuitry
- the ferrite bead would be an annoying space consuming component and I dont care for sourcing, leave that out
- transformers are all going to only have a center tap on the incoming side


question here being, is this going to matter? keeping in mind this will be very low speed or traffic.
if it does matter, how much would it matter and for what cases?
my knowledge of filtering ends at slapping some decoupling caps around mcus

My guess?
If you don't need especially high speeds, and you are using TCP, it will be fine. I'd do at least the bare minimum (tinfoil shielding, maybe inductor coils)... but I don't think you'd need to worry about stuff like optoisolators necessarily. Ferrite beads are nice, but especially for short cable runs usually unnecessary.

As long as your resistors are low tolerance, termination will prevent reflection which is by far the worst kind of EMI (disclaimer: ...in my personal experience with analogue video). Put the terminators as close to the chip as you can, and make the run on the board from there to the connector as short as possible.

Even if you do none of that, though, i expect 10base-T or maybe even 100base-T connections will work fine. 1000base-T, you will probably have packet loss but things will still get through alright.

It's worth noting that this is 100% my intuition, and I have never done this. But given how LONG ethernet cables can be, my assumption is that they are planning for a worst case scenario. Don't skimp on the terminating resistors, though. Those can matter, especially at high frequencies.

Looking at my spare gigabit NIC cards, it looks like they have big boxes that probably contain multiple ferrite windings on a single ferrite bead inside in a small-ish form factor. Looks like they let the ground plane surround one side of the cores, and they leave a large "air gap" separating the ground plane from the outputs from them to reduce capacitance and to separate that side of the cores. Regardless of what you end up doing, it's interesting to look at other boards to figure out how other people do things.
[i.imgur.com] (IMG:[i.imgur.com] https://i.imgur.com/4nfr18pg.jpg)

If you do end up using the cores, i'd suggest stealing something from an unwanted NIC.

I hope what i said makes sense, someone please correct me if/when i went wrong.

This post has been edited by dragontamer8740: May 6 2022, 18:00

Not a bad idea I suppose, so pinned this thread.

My guess?
If you don't need especially high speeds, and you are using TCP, it will be fine. I'd do at least the bare minimum (tinfoil shielding, maybe inductor coils)... but I don't think you'd need to worry about stuff like optoisolators necessarily. Ferrite beads are nice, but especially for short cable runs usually unnecessary.

if guesses from multiple people allign theres at least somewhat of a higher chance of it being right, and I'm going to make test boards at some point anyway (if all my parts ever arrive with some being only sourcable from ebay now)

Looking at my spare gigabit NIC cards, it looks like they have big boxes that probably contain multiple ferrite windings on a single ferrite bead inside in a small-ish form factor. Looks like they let the ground plane surround one side of the cores, and they leave a large "air gap" separating the ground plane from the outputs from them to reduce capacitance and to separate that side of the cores. Regardless of what you end up doing, it's interesting to look at other boards to figure out how other people do things.

If you do end up using the cores, i'd suggest stealing something from an unwanted NIC.

I do have some old network stuff on the attic somewhere but it might be too old to give much insight, non the less a good idea, and theres always thrift stores. the airgap is an interesting idea. I did at some point want to keep this as easily sourcable parts wise to easily make more in the future, but nothing is sourcable anyway, could maybe do something merging footprints to allow for a multitude of sourcable from old boards cores and coils.

good input regardless of ultimate validity, cheers

This post has been edited by cate_chan: May 7 2022, 11:59

Question: Anyone got any suggestions for removing the stain in the bottom left corner of the front of this monitor? I've tried soap/water, goo gone, nothing's worked so far. The rest of it cleaned up nicely.

I'm one berg connector (and 34-pin header adapter) or one DOS boot disk away from having a working 8086 PC (for connecting a Gotek with FlashFloppy firmware to it). Some kind previous owner already maxed out the RAM for me. Might make it run CP/M-86, actually.

[i.imgur.com] (IMG:[i.imgur.com] https://i.imgur.com/nym6vs4g.jpg)

This post has been edited by dragontamer8740: May 8 2022, 01:04

Question: Anyone got any suggestions for removing the stain in the bottom left corner of the front of this monitor? I've tried soap/water, goo gone, nothing's worked so far. The rest of it cleaned up nicely.

not that I have any personal experience with it since I never really 'restore' my old junk, but it just looks like regular age yellowing, be it a bit extreme.
so retrobright possibly? though I guess that'd risk lightening up one stop more than the rest of the case.
bit less agressive theres also the classic (isopropyl) alcohol, might solve in that if its not a yellowed stain but didnt desolve off with water based stuff.

This post has been edited by cate_chan: May 8 2022, 12:19

not that I have any personal experience with it since I never really 'restore' my old junk, but it just looks like regular age yellowing, be it a bit extreme.
so retrobright possibly? though I guess that'd risk lightening up one stop more than the rest of the case.
bit less agressive theres also the classic (isopropyl) alcohol, might solve in that if its not a yellowed stain but didnt desolve off with water based stuff.

No, i'm talking the stain in the corner. Not the yellowing in general (which I am fine with).[i.imgur.com] (IMG:[i.imgur.com] https://i.imgur.com/jphAlmYg.jpg)
And the 'retrobright' stuff makes brittle plastic even more brittle. I've done it before. Hard pass.
I've been able to make a little of the stain stuff come off onto a paper towel, but not much. I have no idea what that stuff is.

Maybe I should open up the monitor (last part of it that I haven't) and see if it's something leaking from inside.

"Aged, but clean" I am fine with. I really don't like partial discoloration, though. It makes the monitor look actually dirty.

This post has been edited by dragontamer8740: May 8 2022, 23:21

No, i'm talking the stain in the corner. Not the yellowing in general (which I am fine with).

ah, I see. completely missed that glancing at the picture without zooming in.

And the 'retrobright' stuff makes brittle plastic even more brittle. I've done it before. Hard pass.
I've been able to make a little of the stain stuff come off onto a paper towel, but not much. I have no idea what that stuff is.

Maybe I should open up the monitor (last part of it that I haven't) and see if it's something leaking from inside.

"Aged, but clean" I am fine with. I really don't like partial discoloration, though. It makes the monitor look actually dirty.

if it also didnt go with alcohol maybe getting it off the physical route is the only option.
any suggestion I can think of would highly likely do more bad than good though, using something lightly abrasive, heating it up slightly, all sure to ruin the texture and make it more apparent than leaving it.
good luck regardless though, maybe it eventually gives up

speaking of how to get things off, and to keep the questions going. I've accidentally let the little utility blade thing on my desk soak in.. something(?) and it stripped off part of the chrome coating. I'd like to just take all of it off but I cant seem to replicate it with just vinegar. any ideas?

PCB etchant? Especially if there's also a nickel coating. Be careful if you try this.

Alternately, maybe something similar to brasso?

Before that, try lemon juice.

I'm trying to think what would oxidize/strip chrome like that.

Finally, you could sandblast it if you have somewhere you can do that.

Not really a question per se, but I managed to greatly reduce interference in my headphones from my powerbook's cardbus 802.11n card using tinfoil. Wish I had a nice way to re-route the antenna to somewhere else, since the tinfoil is also slowing down my connection somewhat.

Actual question: I'm getting a serial driven lcd screen for a Gotek floppy drive emulator. one question before I do something dumb though: Even really early PC's that used the four pin molex connector still had a +5v rail, right? (not just +12)?

I could pull it out and measure it, but I'm lazy. I need to know if I can just use a passive adapter to power a 3.5" drive or drive emulator - the 5.25" drives are using the huge molex 4-pin. This is operating with the assumption that the connectors are the same as they are in a PC XT or 5150.

This post has been edited by dragontamer8740: May 9 2022, 23:03

When a USB Flash drive suddenly becomes "write-protected", does that mean the flash drive has reached its write-limit and can no longer used at all? Not even disk format will fix it?

When a USB Flash drive suddenly becomes "write-protected", does that mean the flash drive has reached its write-limit and can no longer used at all? Not even disk format will fix it?

I've had flash drives do this, but it has been about a decade now since my last one did. I think it meant the microcontroller had decided that it would give up the ghost, yeah.

Although since reads on flash memory are often destructive (and need rewriting after each read) from what I gather, I don't really understand the point.

But from what I can tell you can still remove that write protection, at least on Unix systems. And RMPrepUSB on windows, possibly.
On linux if you're okay with formatting, I'd just try 'cat /dev/zero > /dev/(your flash drive block device)' for starters.

If the microcontroller on the drive is unwilling though that might not work.


The whole situation reminds me of those "corrupted data" flies on PS2 memory cards that the system wouldn't let you delete. BTW, PS2 memory cards used 'destructive read' chips.
Fun fact, core memory was also "destructive read."
Edit: I am wrong, flash memory (NAND/NOR) is not destructively read from what I can tell.

This post has been edited by dragontamer8740: Jun 9 2022, 03:29

Does anyone have a currently working solution for dealing with discord through an IRC client if you aren't an administrator on the discord channel?

I am being forced to use it for something and I would rather have a little bit of usable RAM and CPU time on my computer.

edit: rdircd

This post has been edited by dragontamer8740: Jul 26 2022, 23:46

I just tested this one [mac84.net] https://mac84.net/web/discord-via-irc/

It works both as admin and non admin, but if requires your discord credentials and token, so I highly recommend against using it unless your discord account is throwaway and doesn't use any email/password you don't want to risk compromising. It also picks up pm's by default, without having to connect to it's "channel".

The guide is specifically for a vintage Macintosh, but it should work with any os that can run an irc client (I certainly wasn't running a Macintosh and it works fine)

I just tested this one [mac84.net] https://mac84.net/web/discord-via-irc/

It works both as admin and non admin, but if requires your discord credentials and token, so I highly recommend against using it unless your discord account is throwaway and doesn't use any email/password you don't want to risk compromising. It also picks up pm's by default, without having to connect to it's "channel".

The guide is specifically for a vintage Macintosh, but it should work with any os that can run an irc client (I certainly wasn't running a Macintosh and it works fine)

Thank you kindly.

I just discovered rdircd, but I will look at that as well because rdircd seems a little buggy.

I haven't got any vintage macs, but I do have an Amiga.

And if I have a discord account it is necessarily a throwaway. I hate discord and would never willingly use it.

This post has been edited by dragontamer8740: Jul 26 2022, 23:49

Could use something like [github.com] https://github.com/uowuo/abaddon too, but I can't imagine it's lighter than IRC. Technically against their ToS too I think.

With companies like that everything is against their ToS unless proven otherwise.
No skin off my back.

That's a neat program, too.

If I wanted to use this service, it'd probably be the only way to use it on my powerbook G4, since Blink doesn't build for 32-bit PPC.
Thanks again.

This post has been edited by dragontamer8740: Jul 27 2022, 02:56

Thanks scumbini. Much better.
(click for full size)
[i.imgur.com] (IMG:[i.imgur.com] https://i.imgur.com/lvqJWM0g.png)

Had to do a lot of manual GTK CSS editing to make its "dark theme" actually work, but after I did that it's been pretty OK. Luckily I'd already done a lot of this kind of thing for GIMP 3/2.99, so I was able to just adapt from that.

And my laptop fan isn't screaming while everything I work on grinds to a halt anymore.

Still hate discord, but now I'm not in physical pain.

This post has been edited by dragontamer8740: Jul 27 2022, 05:32

not fully tech related but slightly related to the posts before,
how the hell do you convince people something like mumble isnt "difficult", you just install it and it works yet people act like they have to do 10 backflips just to start it up. the voice quality is so utter garbage on things like discord its unreal. is it too much to ask to just have a decent voip experience, we even had it at some point but then most people forgot about it again.

in case this was too much of a rant I'll slap an actual wondering on if you wish to ignore it:
I'm putting some not too much heat generating dc to dc converters on a pcb I'm still drawing. if I just were to put a big ground plane under it and slap some vias in could it work out? any redflags for this idea? I keep it on a slightly airgapped piece of the board.


This post has been edited by cate_chan: Jul 30 2022, 11:53

not fully tech related but slightly related to the posts before,
how the hell do you convince people something like mumble isnt "difficult", you just install it and it works yet people act like they have to do 10 backflips just to start it up. the voice quality is so utter garbage on things like discord its unreal. is it too much to ask to just have a decent voip experience, we even had it at some point but then most people forgot about it again.

I unironically think that the best course of action with discord zoomers is to belittle them and imply they are retarded, but only if you also have established credibility or weight in the community in question. Do that until they either git gud or make an ass of themselves trying to entrench themselves in their stupidity and unwillingness to move to something superior because it isn't proprietary and corporate enough.

If you don't command that kind of authority, then I suggest calling them zoomers who just don't know better and then proceding to make a 10 second video where you do everything you have to to set up mumble to make them feel dumb, while also answering their questions.

I have successfully used both of these tactics before on leddit to convince people to join an IRC channel.

But basically, make them feel retarded for using Discord. Because they should feel retarded for using it.

Or you could pose it as a challenge... but I bet most would instantly give up if they got a challenge like that. Anything to avoid learning jack shit about how a computer works.

And yeah, I too fondly remember a time before I knew what discord was. I think I first heard about it in late 2015. And I instantly hated it.
Sometime prior to 2015, I used to be on a minecraft server that used Mumble, it was pretty nice. I bet they've gone full retard now, though. Just like everything else minecraft.

Edit: just checked my desktop (was already using it for minecraft around 2013-2014); it still has mumble installed on it. Wow. Surprised it survived the qt4 and python2 culls.

I'm putting some not too much heat generating dc to dc converters on a pcb I'm still drawing. if I just were to put a big ground plane under it and slap some vias in could it work out? any redflags for this idea? I keep it on a slightly airgapped piece of the board.

Depending on exactly how much heat, assuming it doesn't make the board delaminate, this could work. Copper is an excellent thermal conductor.

But I'd make the board edge stick out farther if I were to do it, just so there's more surface area exposed. Or use a tiny fan that moves some non-zero amount of air. Any air flow whatsoever makes a huge difference.

I think some modern PC motherboards do what you are describing, though, for their on-motherboard voltage regulators.

This post has been edited by dragontamer8740: Jul 31 2022, 07:28