Saying Hi/ My build

[ThisWayUp]

Only a small update:

I pulled a SST 39VF512 90ns Flash ROM from an old NVIDIA graphics card and tested it out, works great! Whipped up a 3.3v circuit for it using a TOKO TK11432M regulator. Puts out a steady 3.21V. Haven't hooked it up yet but this should give me a slight edge over my AT28c256 and has more room for future projects. Now, with a 3.3v source I can easily implement any other 3.3v elements into my project if need be.

[ThisWayUp]

Received my HP PS/2 keyboard today and it does work, I'm typing this post with it right now. Its actually very nice to type on, makes my wireless modern keyboard feel spongey and much less responsive. I guess my 6502 will be my go-to for luxurious typing experiences Will post updated pics after I get it hooked up.

[ThisWayUp]

This keyboard definitely works. However, my project is broken somewhere. I am using 2 74HC595's to take in the 11 bits of data from the keyboard but they aren't putting anything out. I'm going to look over the datasheet but everything appears to be connected correctly. I was using some Chinese knockoff 595s and swapped them for 2 TI that I had in a 'logic beginners' kit but same thing. All outputs sit at 5V. If I can't figure it out and whip myself into a homicidal rage I'll resort to pestering everyone here for help but half the fun (if that's what one calls it) is solving the problems yourself.

[BigEd]

It's almost always possible to get to the answer, by careful checking, and the application of doubt to your assumptions, and working from hypotheses to consequences.

I must point out, though, that it would be sufficient to say that you replaced some knockoff components. Saying "chinese" in that context is a mistake, in several different ways, and I find it problematic. There's one person here who has consistently failed to understand this point, but there's no need to follow a bad example. (I apologise in advance for the possible thread derail: I recommend a new thread anyway, for a debugging adventure, with an appropriate title. As you move from one conundrum to the next, consider a new thread for each. It helps with finding information later, and it helps to avoid megathreads, and also to minimise the effect of thread drift.)

[ThisWayUp]

Ok, I wasn't sure how to structure this. I figured keeping the build 'adventure' in one thread would keep from littering the other sections with noobish spam but whatever you suggest. Also, in this context, this is chinese knockoffs, it says so on the package (not sure why the pictures are sideways )

[BigEd]

OK, if someone buys the cheapest stuff, they will probably find themselves buying from China, and if they are not careful about the supplier, sometimes they will get bad stuff. If they think that's a problem with Chinese suppliers, they've made an error, because it was their choice to proceed in that way. China is a major supplier of manufactured goods and Chinese suppliers quite capable of shipping good product. By putting price first and failing to take into account the customer-supplier relationship one makes an error. One has failed to understand the way global commerce works and failed to understand cultural differences.

We have threads elsewhere which aim to address this problem, of how to buy online without coming a cropper. So it's best if we don't rehash this over and over in other threads.

Speaking as you did is essentially perpetuating a lazy stereotype, and you're not the only one to do that, and I'm rather tired of it, which is why I mention it now. Nationality is very rarely a useful way to categorise things on this forum.

[Dr Jefyll]

ThisWayUp, if you do end up asking for assistance, be sure to post your circuit so we can examine it. And in any case, be sure you're aware of the function of the *two* clock inputs on the '595.

-- Jeff
PS:

ThisWayUp wrote:

[...] but same thing.

Looks to me as if the "knockoffs" may yet prove to be satisfactory.

[enso]

Racism aside, it is practically redundant to qualify any electronic gear and components with the word Chinese, as pretty much everything is made there.

[BigDumbDinosaur]

ThisWayUp wrote:

Ok, I wasn't sure how to structure this. I figured keeping the build 'adventure' in one thread would keep from littering the other sections with noobish spam but whatever you suggest. Also, in this context, this is chinese knockoffs, it says so on the package (not sure why the pictures are sideways )

Those look to me to be counterfeits. The SN prefix on the part number is a TI thing. Whomever made/remarked these chips were likely trying to fool the buyer into thinking they were getting TI product.

[ThisWayUp]

I'm fine with it as long as they work! And as far as counterfeits go, these look pretty good and have pretty good quality pins unlike most that break when you look at them. What's even more confusing is that I tried to 'verify' them in my TL866II+ that supposedly can test logic chips, it said the 10 I tested were all bad. But then I tested the two TI 595's I have and it said those were bad too I guess today just isn't my day. That's why I started a thread for the actual issue and if I have the energy after loading an OS on a laptop with a fresh SSD after the HD died I might also hook up an arduino and try to use the registers to blinky some leds.

[BigEd]

Thanks for the new thread. I'm not sure I personally can help, but I'm sure someone can.
PS/2 keyboard logic issue

One of the difficulties when debugging is knowing what to doubt. If a circuit worked before, and you changed one thing, and you know what it was, that's the easiest case. But with something newly constructed which hasn't yet worked, using parts not used before, that takes some methodical investigation.