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Osborne 1 Video Adapter.

That is a so-called hybrid module or a potted ceramic PCB. It uses surface mount components and direct carbon composition resistors on a ceramic substrate.
If the potting compund is soft you could try and remove it carefully. If it is solid then do not even try, chances are the substrate will break.

You could try and X-ray it :)
 
With any of these sorts of adapters there are many qualities they need to be ideal. Some VDU's are fussy about the signal, some are not.

One is that the duration of the sync pulses are correct. For the H sync 5uS is fine. The vertical Sync pulse is the one commonly messed up, it should only be a maximum of about 3 H periods or 190uS wide. In a few vintage computers and adapters they fouled this up and made it closer to the vertical blanking interval which is around 1mS. This causes some, but not all VDU's , due to an upset in the sync separator, to get a tear in the picture at the top. They made this mistake in the SOL-20.

Also ideally, the video signal should be both horizontally and vertically blanked (during retrace time). This might be done in the particular computer, but it might not. The H blanking time is about 10 to 10.2uS and the vertical blanking close to 1mS.

And ideally the sync pulses are XOR'd with each other not OR'd.

Then there are the levels and impedances to consider. Ideally the the output impedance is set at 75 Ohms and the un-terminated video voltage is 2V. When terminated at the other end of 75 Ohm coax, with a 75 Ohm resistor, at the VDU, the pp voltage is then 1V. Of the 1V, the lower 1/3 of that is sync pulse ans the upper 2/3 is video voltage. Also, if there is no output coupling capacitor to isolate the DC Component, the sync tips should be sitting close to ground, or at least withing a few hundred millivolts of it. One easy way to get an exact 75 Ohm output and set the un-terminated voltage to 2v pp is to use an RF capable OP amp, with a 75 Ohm resistor in series with its output, such as an AD8056, they are cheap enough.

There is more to making the "ideal video adapter" for a vintage computer than meets the eye, but it is amazing what you can get away with, no blanking, and with a couple of monostabes and some diode mixing OR'ing the syncs.

In computers like the PET, to simplify the VDU, the H pulses are "drive pulses" fot the H output stage and are noting like a sync or blanking pulse. Also the Vertical drive pulse is equivalent to a blanking pulse, not a sync pulse. So to create a proper composite video signal from those signals, requires a number of monostables and gates.
 
So the seller on aliexpress has been sitting on my order for 2 weeks. I confronted him and now he says he doesnt have any 10k pots. I need to get a refund and try another vendor. God these chinese sellers are terrible. If you dont have the product.. do a refund.. Dont just sit on the order!
 
So the seller on aliexpress has been sitting on my order for 2 weeks. I confronted him and now he says he doesnt have any 10k pots. I need to get a refund and try another vendor. God these chinese sellers are terrible. If you dont have the product.. do a refund.. Dont just sit on the order!
They wait in hope.
 
Hugo, a question about video timing - Was there ever an accepted timing standard for computer video output for 15KHz monitors, that were's PAL or NTSC, but either mono or color with separated signals, whether analog or digital?
 
So the seller on aliexpress has been sitting on my order for 2 weeks. I confronted him and now he says he doesnt have any 10k pots. I need to get a refund and try another vendor. God these chinese sellers are terrible. If you dont have the product.. do a refund.. Dont just sit on the order!
{veering off-topic}

Having a terrible time with Creality.

Never buy from them ... "shipped from local Australian warehouse" in Sydney .. excellent, it'll be here in three days then ... two weeks later it arrives with a "Hainan Airlines" sticker on it. Hmmm ... I don't care where it came from, just don't treat me like an idiot and lie to me ... if it's coming from China, then tell me so I'll know it'll take a few weeks and I won't be sitting like a puppy at the door each day expecting it to arrive. Didn't help that the tracking number they provided didn't work - had to track down the courier which said it was "picked up in Sydney" where it apparently sat for two weeks ... I live 4½ hour drive from Sydney ... it doesn't take two weeks to get here. So, it came from China and they faked it ... why? No response ever from their email contact when I was querying for a correct tracking number, etc.

(Reason for my impatience was that I wanted to print the Gotek mounting bracket for my Osborne 1 ... so slightly on-topic)

Unpack it (an Ender-3 V3) ... nicely made ... aaaaand, it doesn't work.

I posted my issue also on their "official" Facebook group and had a few replies but it seems to be mainly other users. Never got a reply on their "official" forum.

Did get a response from their customer support email ... "we'll send you another motherboard or you can return the printer" ... "I'll return the printer" (they have a 14-day return & refund policy) ... "okay, if you insist, we'll send you return details" ... silence.

So if you must buy a Creality 3D printer ... don't buy it from them, even if they apparently have a local presence! Buy it from Amazon so you can just return it when it arrives non-functional.

I've been told to look at Bambu ...
 
I've been told to look at Bambu ...

+1 for the Bambu. They are amazingly fast and something about having a "Ludicrous Speed" setting is tantalising... Though if you set it, you need a filament to keep up with the print speed.

I have a Flashforge Dreamer, An Up300 (Tiertime) and a Bambu Carbon X1.

Biggest issue with the Bambu is it doesn't handle overhangs anywhere close to the Up300's capability, but it's no worse than the Flashforge.

Next biggest issue is getting the right filaments is a little tricky, but they have a nice range of engineering plastics which handle outdoor heat very well.

Lately I've been trying it with Nylon6/CF mix, and the PETG/CF is my go-to choice for general use.

It also prints color pretty well. And it likes it's own filaments, which, while well available, are about 80% more than other filaments, though if you want to find a good setting yourself, you can use any filaments. It's also easy to change out the print head when it jams the nozzle.

Third biggest issue: It's an Ecosystem! A semi-walled-garden. It's the first time you can buy a printer without knowing how to make anything - and it's *really* good at that. You can share models with other people and the quality of the sharing is excellent. Way beyond anything else on the market. However keeping it off the cloud is a PITA. You can do it, and set it up for local print only, but it's not as straightforward as the OOBE. It's OK once you get used to it though. And you can still set the camera to timelapse any prints or show you what it's printing. But it's not as good an experience as the cloud model.

Pluses - Has good autolevelling, if a bit slow, tells you when maintenance is required, shows you how to do it, good community support. and some of the community models are so good that there's no need to remake them ( there's a lot of community competition for quality ). Great for printing toys... And yeah, the site is full of guns to print, but they are all toys - no crazy stuff likely to cause them to be banned. There are lots of automatic spool change systems too.

On the downside for all 3D printer manufacturers, Darth Stratasys is trying to destroy everyone and build an empire. I really hope they fail since they are patenting prior art and obvious stuff like crazy.
 
Hugo, a question about video timing - Was there ever an accepted timing standard for computer video output for 15KHz monitors, that were's PAL or NTSC, but either mono or color with separated signals, whether analog or digital?
I mainly worked with analog video, PAL, NTSC and the timing standards for these are well known. I'm more familiar with these than computer signals. The Chroma sub-carrier is easily switched off if access to the circuit that generates the composite signal is there. You can also switch of just the burst and the set's color killer will deploy the TV to monochrome, but there will be patterning from the high frequency luma signal with the chroma, so it is not as good. Also the sync generators for items like PAL & NTSC color cameras, video test and other generators, and off air TV signals have proper interlacing with equalization pulses too. You can also combine RGB signals to a good quality luma signal, or just use the green if desperate.

However, when it comes to computer generated signals, especially from vintage computers, it appeared to be "anything goes" looking at the circuit designs. If the picture can come into lock, even with slightly non-standard signals for the VDU, and has reasonable resolution it was "good enough"

Initially many signals were not interlaced and the fields merely scanned on top of each other. In the Dazzler for example, it was a fairly poor attempt to generate NTSC standard signals, it doesn't even use a suppressed carrier modulation system for the chroma, but, most color VDU's were very forgiving. It seems to have taken a while before early computers were designed with more specification compatible signals for NTSC and PAL VDU's.

But then, generally it was as though the manufacturers wanted to set their own standards for computer video. RGB style systems rather than composite video of TV systems, higher scan rates and better bandwidth in the video amplifiers and finer dot pitch color CRT's than what any common garden TV PAL or NTSC VDU could produce, in the interests of detailed graphics of course. Looking at the color rendition on a composite signal from a IBM CGA card that gives a different result on a color NTSC VDU than a CGA VDU, like the 5153. It is as though they didn't really care about a color composite signal, but cared a lot about the CGA signals.

I think when early computers came out, the costs were a barrier (except perhaps for those buying IBM computers that came with recommended VDU's like the 5151, 5153 and 5154), so the makers provided composite video outputs so the buyer could deploy an existing TV set or VDU, like those used in CCTV systems, even though it would not have been as good as a VDU specifically designed for the task with an RGB system of one kind or another or a high reso dedicated monochrome VDU. But the IBM 5151 was a good choice, though they cut back on the circuitry in it, making its H output stage vulnerable to damage from incorrect signals.The 5153 and 5154 color VDU's don't have that issue.

Interestingly the same sort of thing happened when aftermarket CDI's for cars. When they came out in the mid 1960's the manufacturers claimed that you did not need to change the existing Kettering style ignition coil. (the extra cost would have been a barrier). However, this was not entirely true because a custom transformer style coil with a Ferrite core, more suited to the task of CDI, would have yielded at leas 4 times the spark energy with the same drive unit, talk about telling a Porky. But it would have made the whole box of tricks a lot more expensive and put off a buyer.

One monochrome VDU which I think is an interesting case in point, is the one in the IBM-5155 computer. It was not a re-purposed TV signal standard VDU, as some small VDU's used in early computers were. I was designed by Zenith with a wide-band computer composite signal in mind. It has a CRT with a very small focused spot size. Geometry correcting magnets on its yoke for a perfectly rectangular raster scan, a video output stage with near twice the bandwidth of that seen or required for a TV VDU. And it can produce highly detailed graphics as a result. The only error IBM made with its deployment was to feed it with the composite color signal from the CGA card (hijacked from a connector that was intended initially to feed an RF modulator). The color carrier beats aggressively with the higher luminance frequencies and due to the excellent response in the video amplifier in the VDU, this results in objectionable patterning on graphics. The fix is to disconnect the resistor that mixes in the chroma to the video output transistor on the CGA card. These particular VDU's "turned my head" and I became unable to resist their power over me:

www.worldphaco.com/uploads/THE_AMBER_COMPUTER_VDU_PROJECT.pdf

One other interesting feature of these VDU's, not common ( Though I have seen it done in mil spec Radar VDU's, using a UJT) Zenith created the vertical scan oscillator from two transistors wired as a PUT (programmable unijunction transistor) the method avoids the need or requirement for a vertical hold control. Makes me think that the designer probably did stuff for some of Zenith's mil spec systems.
 
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That makes sense. I had issues with setting up my timing, and I wanted to simplify the circuitry as much as possible so that the raster generator could fit on two small chips, common during the 80s.

I tried for RS-170 timing, but that's 60hz. I never found a comparable timing schema for 50Hz. So I ended up mixing PAL and RS-170 which is a bit of a mongrel-breed signal.

It looks something like this;

LOKI Architecture - Frame 54.jpg


It's not really any standard now... But it is particularly easy to encode with minimal logic. Two PALs is all that is needed to generate the addresses, bus arbitration and sync.
 
So I received some of these boards from @cj7hawk Thank you again sir!

I boneheadedly forgot to order a couple of the components so I am waiting on that to test them out. Once I successfully build one, Ill make a few more so if anyone with an Osborne 1 wants a composite video out adapter here in the States send me a PM.
I haven't been able to figure out the PM system here yet (maybe my account is too new?) but I'm interested in one of these if they are available, thanks!
 
So the seller on aliexpress has been sitting on my order for 2 weeks. I confronted him and now he says he doesnt have any 10k pots. I need to get a refund and try another vendor. God these chinese sellers are terrible. If you dont have the product.. do a refund.. Dont just sit on the order!

... or the ones on ebay that say they're in "Sydney" or "Melbourne" but not really specific, so you order from them assuming it'll arrive in a few days rather than two months from China ... but they then order from Aliexpress in China and it ends up taking two months ... "from Sydney"
 
... or the ones on ebay that say they're in "Sydney" or "Melbourne" but not really specific, so you order from them assuming it'll arrive in a few days rather than two months from China ... but they then order from Aliexpress in China and it ends up taking two months ... "from Sydney"

They aren't being dishonest - They are just shipping from Melbourne, China or Sydney, China. I heard of those two suburbs before. China pretty much has a counterpart for every city in the world now.
 
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