Question about cheap HDMI converters

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Question about cheap HDMI converters

Hi there,

this is my first message in the forum. I'm Pedro and I just started the journey to build an Apple I. I have already most of the components (my chip set is Bernie's and it's on the way), and I'm trying to document myself as much as possible.

 

I have a question about the video output and the possibility to use a composite-to-HDMI adapter like this one: https://www.aliexpress.com/item/1005001577218315.html

 

Any of you had a good experience with these converters?

 

Txs!

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I got my parents one that

I got my parents one that looked about like that to hook their VCR up to their new TV. It worked as expected. Haven't tried it with a computer.

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I have one that looks like

I have one that looks like this except it is white with black markings.

 

https://www.amazon.com/Converter-Amtake-Composite-Adapter-Supporting/dp/B07MJTR9KS

 

So far it has worked fine with my cheap Emerson 720p TV.

 

FWIW, the results are not that different from the Emerson using the composite inputs on the TV...

 

The convenient thing is this TV has multiple inputs that can easily be switched between with the remote...  So one computer can be hooked up to HDMI1 and another to the composite, and I can flip back and forther.  If I had anotther HDMI converter I could switch between 3 devices because the TV has two HDMI inputs...  I could even hook up yet another one to the broadcastTV input if I wanted to use an RF modulator...  and I'd still have one input I wasn't using...  the SVGA...  I have a VGA scaler on one of my //e, but I don't think it is SVGA compatible.

 

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Thanks for your replies. In

Thanks for your replies.

 

In particular my question is if such converter can work with the video output of an Apple I.

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Hi,anyone tried these HDMI

Hi,

anyone tried these HDMI converters?

 

I'm planning to build the board this week and I'd like to know if I could expect video output using this, as I don't have handy right now a vintage monitor supporting composite.

 

Thanks!

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Please be patient ...

... I have one of those incoming. Actually, yesterday I got one, but instead of the AV->HDMI I had ordered they sent me the HDMI->AV version, which almost looks the same except for the imprint, so back to the vendor it went (Ebay return procedure). 

 

This only proves how idiotic and mindless these Chinese are who designed and built these converters. It would have been possible to have the plastic shells be injection molded with two different colors or at least shades of grey. But noooo, they had to make them look almost the same, so they can easily be mixed up.

 

So when you order them, you really have to look thoroughy at the  description to order the right version. But even if you do so, you are the the mercy of the guy in the warehouse who picks the items off the shelves. In this case, a fail, like "F".

 

This problem now has infested all fields of commerce. Just two weeks ago I got wrong character generators from an otherwise reputable IC broker: they sent me the CGR-005 version instead of the CGR-001 version I had ordered. It's a different character set that is useless for me. Back to the vendor they went. This  is why I can't sell any kits  anymore right now - I'm out of character generators (never had enough of them).

 

It seems that nobody cares anymore to do the job right, regardless in which field in human endavor. I can see faults everywhere. Either you get the wrong parts that were not ordered, or some are missing, but were paid for, or the packing is lousy, and stuff gets damaged, it's just terrible. It's now a rare event to get the right things, as ordered, and properly packed, and on time, as it used to be. No economy can work with such a failure rate. It looks like intentional sabotage, but more likely it's just morons. Whether caused by birth complications or by drugs, I don't care. The outcome is the same. How and why did the capable people disappear ?

 

If I ever get the right AV->HDMI converter, I will tell you about it. Stay tuned !

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Hi pfuentes69 I can confirm

Hi pfuentes69

 

I can confirm the AV2HDMI "Mini" converter you have linked in your first post does not work with the Apple-1 Video Signal. Nor a bunch of other cheap chinese AV converters out there. Either you get a black screen or nothing. I was trying hard to find such a solution to run my Apple-1 clone on a HDMI or VGA display. I failed with following adapters:

 

Retrotink 2x pro

AV2VGA

SCART to HDMI Adapter

AV2HDMI Mini

 

I tried these adapters on several Displays or TV´s with the same result. These adapters dont understand the Apple-1 signal at all. Same story with a lot of older LCD TV´s with Composite Input. I had no success. I guess you should better look for an cheap CRT Multiscan Monitor or even better a Apple-2 Monochrome Monitor. I found some cheap on Ebay.

 

However - I did not waste the money as these adapters work reasonable well with my other retro computers like from Commodore or Sinclair. But that´s Off Topic ;-)

 

If there is somebody in this forum having success with any adapter or upscaler on the Apple-1 please let us know. 

@UncleBernie - Fingers crossed that you have more luck with your order!

 

 

 

 

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Thanks for the updates

Thanks, Denis1973 and UncleBernie

 

Well... that's unfortunate, although not totally unexpected. I don't know if the mods proposed by UncleBernie to sort out the signal can improve the situation... I guess you'll let us know.

 

I know someone that can lend me a CRT... and maybe I can find something small and nice for my setup, although here in Europe is not that easy to find these thigns, and the shipping costs from the US (and the risks that it arrives broken) are too high.

 

 

 

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Finally got the "right" mini AV2HDMI ...

... and can confirm it does not work at all with the unmodified Apple-1 video signal, there is no signal to be had.

 

With my Apple-1 video fix, you will get a picture, but there is a catch: it's not stable but wanders around in the horizontal direction.

 

To investigate how serious the problem is, I replaced the 5.1 kOhm base resistor of the mod with a 20 kOhm trim pot. I could not find any position (corresponding to HSYNC width) where the picture would stop to slowly move sideways and then pop back, move, pop back, and so on (the slanted picture came from holding the camera at an angle, it's not a bug of the converter):

 

 

Ironically, the converter sometimes locks into a sort of split screen configuration:

 

 

where the sideways moving stops for a while. But this is not a stable operating point. The thin grey vertical line is the known artifact from the video fix, and the real HSYNC happens after that. Note that the line is not curved nor wiggly so in this case their crappy horizontal digital PLL has acquired lock, but unfortunately with a massive but stable phase error (otherwise the line would not be straight).

 

My professional judgement is that these converters were designed by idiots who have no idea about the real analog video world and they don't understand how to design a digital PLL neither. Maybe the work of college grads ? Or some design stolen by industrial spies before it was finished and all the bugs ironed out ? With the Chinese, anything is possible. They sell a lot of crappy and counterfeit products, such as the TO-3 transistors they re-stamp as LM323K regulators, or the 555 timers they re-stamp as Signetics 2504V, and poisoned dog food. 

 

But on the other hand, this gadget is so dirt cheap ($6-$7) that it might serve as a stopgap solution until you can find a more suitable monitor. But it will need my video fix  to work and some fiddling with the trim pot to find a position where the horizontal movement is not too bad. Also note that the converter must be powered by a USB cable which is provided (at least the mine came with one) but they don't provide a wall wart or such where you can plug that USB cable in.

 

So far, so good, or so bad. As far as I'm concerned, end of story. Remember: you get what you pay for (or less). But never do you get more !

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Oh wait it gets worse !

I hooked an Atari 600XL which I just have refurbished and extended with a video and audio jack (that works fine with a regular analog TV) to this little crappy video converter, and expected a better outcome than with the Apple-1. Not so ! The video quality is terrible and the idiots who have designed this thingy obviously never have heard of digital smoothing  filters to remove artifacts from upsampling. Oh my, we used these filters even 25 years ago in our last generation of TV ICs meant for CRT based TV chassis. The patents are out there and they are long expired. Some date back to the late 1970s / early 1980s when ITT's Lubo Micic created the first Digivision chip set. But these Chinese geniuses obviously don't know where to look.

 

Here are the photos showing the terrible picture quality:

 

 

 

And here a closeup with the  sampling artifacts being more visible:

 

This converter is a piece of junk. An inherently  flawed design. Like so many Chinese  made products, an utter waste of ressources, materials, and silicon chip area. Maybe this is the reason why they are so cheap ? They cost $6-$7 including shipping. The vendor who sent the wrong one to me just refunded the money and did not even want it to be sent back to him. So, these are disposable items nobody wants, having no intrinsic value.

 

Be warned. You get what you pay for. Pay with peanuts, work with monkeys. So true !

 

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Thanks, UncleBernie!Well...

Thanks, UncleBernie!

Well... this will not be useable, but on the plus side, I could get some kind of picture and at least confim that I'm having video output... until I can get a proper screen. I'm on the quest of a CRT, but so far I wasn't lucky enough to find anything small at a reasonable price (including shipping to Switzerland).

 

I just wonder if a less-crappy converter could do the job when combined with your mods, although nowadays you always get the chances of just paying more for the same circuitry in a nicer box...

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If you are looking for a

If you are looking for a "less-crappy" converter, the Extron DSC 301 HD  definitely fits that description. The cost, however, is completely different as well.

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That $7 coverter really is

That $7 coverter really is crappy.  I've got a couple of $15 converters that produce significantly better results than that.  But, twice the price, so maybe you do get what you pay for to an extent.

 

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