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TI-99/4A with PAL


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#26 apersson850 OFFLINE  

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Posted Tue Apr 30, 2019 8:01 AM

A monitor which supports both PAL and NTSC is, by defninition, independent of the mains frequency. Otherwise it wouldn't be able to support both versions of input, at least not without moving it from the US to Europe, for example. I've never seen any such monitor that couldn't accept both inputs regardless of the mains frequency.

One could imagine that PAL would only work with 50 Hz supply, and NTSC only with 60 Hz supply, but no, I've never seen that.

 

And it's Hz, not hz. Units named after people start with a capital. So it's A for Ampere and Hz for Hertz, but m for meter and s for second.



#27 mizapf OFFLINE  

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Posted Tue Apr 30, 2019 10:58 AM

Units named after people start with a capital.

Wow, I did not see that coming. Interesting! I never thought about that.

 

Somewhat like "two-letter top-level domains indicate countries". I guess not everyone knows that either (and it is misused anyway).



#28 adamantyr OFFLINE  

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Posted Mon May 6, 2019 8:32 PM

 

So I don't need to purchase a transformer at all? That's good news! Those suckers are pricier than I thought.

 

As for the TV, I just picked up a monitor on eBay that says it supports both PAL and NTSC. But from what you're telling me, THAT may require a transformer, yes?

 

This is what I got, the 17" model: https://www.accu-tec...t_en-201001.pdf

 

So this monitor arrived today... it came with an EU plug, but a standard 110v cable also worked on it. I presume for PAL I would need to get a converter? It has an auto PAL/NTSC mode system, so I imagine if it gets the right voltage it will switch.

 

The quality of the picture is astounding on NTSC. There is virtually NO corruption at all. The colors are difficult to get strong on my CRPG; the black background seems to steal a lot of the color, but that may just require me to play with the tint and color levels.

 

The picture is so good, in fact, I'm kind of regretting buying a PAL TI. I suspect the picture won't get much better than that.



#29 JB OFFLINE  

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Posted Mon May 6, 2019 10:45 PM

 
So this monitor arrived today... it came with an EU plug, but a standard 110v cable also worked on it. I presume for PAL I would need to get a converter? It has an auto PAL/NTSC mode system, so I imagine if it gets the right voltage it will switch.
 

It probably changes modes based on the signal input, so just feeding it a PAL signal will be enough to engage PAL mode.

#30 adamantyr OFFLINE  

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Posted Wed May 15, 2019 7:36 PM

Okay, I got the PAL TI today. As stated here, a regular US Power supply works fine with it.

 

However, I can't figure out how you hook up the RF modulator to a monitor? It just has one white cable with what LOOKS like a composite male pin, but it's a little too small. Plus, no audio at all. Do I need to get a PAL monitor cable from somewhere?

 

EDIT: Based on the discussion on this thread here, I see that no composite video cable for the TI was ever made for PAL version. That rather sucks.

 

http://atariage.com/...6-pin-av-cable/

 

So now I'm left with, how the hell do I use this? NONE of my composite monitors have a compatible connector. Incidentally, I have the older PAL modulator, the silver and black box variety.



#31 adamantyr OFFLINE  

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Posted Wed May 15, 2019 9:11 PM

I'm doing some research, but I need help here before I spend any more money on this.

 

I see that PAL male to F-type adapters exist, but that would in this case only allow me to hook it up to a TV's antenna port, if I understand it correctly.

https://www.amazon.c...,aps,204&sr=8-3

 

To hook it up to a composite monitor with A/V cables, I'd have to still have a coaxial adapter and THEN also use a second RF modulator to split it to the requisite cables.

https://www.amazon.c...=A3LYGL3VCPC7H8

 

Anyone here of a cable-making hardware mind-set that is up to the challenge of making a 6-pin DIN composite monitor cable? I'd gladly pay for one...

EDIT: Nevermind, I see this isn't possible because the 6-pin DIN would require an extremely customized cable with an RGB 6-pin style connector AND an audio cable. Plus, at least according to the TI Tech Pages: "The Y, R-Y and B-Y video signals from the TMS9928A and TMS9929A require an external encoding circuitry to drive a RGB monitor." It sounds like I should just live with trying to convert a coax cable to coaxial then composite.

 

Further EDIT: It appears that there is no such thing as a coaxial to composite adapter. They ALL go the other way. Apparently the ONLY way I can actually view it is to use an old VCR, which fortunately I have, which can take an antenna signal in and then convert it to the composite ports.

 

I'd love to get one of the custom component video cables, but it appears they are out of stock and no longer being made.



#32 blackbox OFFLINE  

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Posted Thu May 16, 2019 5:38 AM

Hi.
 
EUROPEAN PAL CONSOLE TO MONITOR (Analog Composite Video):
 
The PAL console does not have RGB, it uses a colour difference output from the console- apparently to make it easier to work with the French SECAM tv system.
 
To enable the PAL console to work with a PAL tv set you needed a PAL MODULATOR- the first part of which took the colour difference signal from the console and created a composite video signal, which was then fed into the small metal box inside which was the actual  RF modulator.
 
It follows that if you open up your TI RF Modulator, you can have access to the composite signal that is fed into the actual modulator box!
 
Details of this can be found on the lovely web site at ti99iuc.  The photographs and a little web translation should get you past the Italian.    
 
The following link takes you to a selection of related articles:
http://www.ti99iuc.i...amp;cerca=Cerca
 
The output after conversion is ANALOG COMPOSITE, usually fed to tv sets etc via phono (RCA) cable.   
A modern monitor may be unhappy with such a low definition signal.


regards
Stephen

Edited by blackbox, Thu May 16, 2019 5:47 AM.


#33 mizapf OFFLINE  

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Posted Thu May 16, 2019 5:46 AM

Typically, the PAL modulator is fed into the HF (antenna) input; this is what I did with the flatscreen TV/monitor for the photos that I posted here. (See the pictures in the first post.)



#34 blackbox OFFLINE  

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Posted Thu May 16, 2019 5:52 AM

Hi Mike,

Yes, Adamantyr lacked a TV with a tuner so was using an old VCR to feed the TI rf output into and then on to a modern set (this is actually what I do here!).

The TI99IUC conversion allows you to cable from a TI modulator directly to a monitor or tv that accepts analog PAL composite video (sound is always a separate cable), and as adamantyr has a metal modulator, it will be a lot easier than the tricky stuff using the plastic cased tv modulator.

regards

S

Edited by blackbox, Thu May 16, 2019 6:50 AM.


#35 adamantyr OFFLINE  

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Posted Thu May 16, 2019 8:55 AM

Good to finally find posts on the modulator modifications, many of the links from the prior thread 404'ed on the subject.

 

I'm not a hardware guy, though, so I'd have to find someone who could do the modification for me.



#36 Asmusr OFFLINE  

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Posted Thu May 16, 2019 9:02 AM

Good to finally find posts on the modulator modifications, many of the links from the prior thread 404'ed on the subject.

 

I'm not a hardware guy, though, so I'd have to find someone who could do the modification for me.

 

I tried this mod and the result was a very bad rolling picture. I think I ended up damaging the modulator. But apparently it's working for some people.



#37 adamantyr OFFLINE  

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Posted Thu May 16, 2019 9:08 AM

 

I tried this mod and the result was a very bad rolling picture. I think I ended up damaging the modulator. But apparently it's working for some people.

 

Yeah, that would be a legit fear of mine as well. If the modulator breaks, this TI is for me just a nice door stop.



#38 blackbox OFFLINE  

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Posted Thu May 16, 2019 11:41 AM

I have found the following historic note, which refers to connecting a TI99/4a European console directly to a monochrome monitor. I had a mono monitor connected to my TI for a while.

The need for a high impedance at the monitor end may still apply - worth considering anyway. Modern equipment does seem to have lower impedance matching than older historic equipment.

quote
The input impedance of the monochrome monitor should be fairly high (above 560 ohms) and not 75 ohms (which is a standard value), as the video output circuit of the console can be damaged feeding a 75 ohm load. Viv Comley
unquote

s

Edited by blackbox, Thu May 16, 2019 11:41 AM.


#39 ti99iuc ONLINE  

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Posted Thu May 16, 2019 1:23 PM

[...] 
Details of this can be found on the lovely web site at ti99iuc.  The photographs and a little web translation should get you past the Italian.    
 
The following link takes you to a selection of related articles:
http://www.ti99iuc.i...amp;cerca=Cerca
 
The output after conversion is ANALOG COMPOSITE, usually fed to tv sets etc via phono (RCA) cable.   
Then you may find that your modern monitor is really unhappy with such a low definition signal.
[...]

 

many thanks for your kind words and support blackbox,  I am always happy when the job done on TI99iuc website is appreciated and useful for other enthusiasts 99ers.
unfortunately anyway the link you posted is not working, i do not know what was happened in copy and past,
the right one is this:
http://www.ti99iuc.i...=Mod_and_Tuneed
 

 

I tried this mod and the result was a very bad rolling picture. I think I ended up damaging the modulator. But apparently it's working for some people.

 

Well, i must say that i modified 50+ modulator (Metal Version) at the moment and no one had problems. Most of the problems i had was from incompatible monitor/TV.
For example on all LCD i had an ugly screen compared on CRT TVs. 
the same problem i had using the original TI interface PHA2037 with SCART RGB, only CRT gave a nice clear screen.

Plastic version of the PHA2036 instead have a mod a bit more complicated, but only one at the moment had really problems.

 

 

the other solution with a component YUV2 cable instead:

http://atariage.com/...-2#entry3971397

Have a compatibility problem with signal on some of the LCD i tried it, for this reason them are no longer made from the ebayer seller, he had a lot of problems with users that purchased cables.

I have tried it on various brands of TV, mainly: Relisys, Sony, Samsung, United
all Samusng TV/monitor i tried it was not working (out of range, Signal not recognized or showed with glitches)
on some of the sony i tried it worked and the same on most of the chinese not famous branded TV.

Which is the model of the TV you used and it works Rasmus? I would like to add to my compatibility list please :P


Edited by ti99iuc, Thu May 16, 2019 1:24 PM.


#40 adamantyr OFFLINE  

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Posted Thu May 16, 2019 8:02 PM

Okay, an update...

 

I had to order a PAL Male to RF adapter part so I could hook up the PAL Modulator to a US TV or VCR.

 

Unfortunately, on the VCR, I get nothing. I happen to have an old VCR/TV combo that has an antenna in, so I hooked up to that directly.

 

That works, but the ONLY channel that comes through is channel 34, and it shows a rolling black and white picture of the TI screen. So even if the VCR COULD go to channel 34, it would probably show the same.

 

On the plus side, the console is confirmed working. On the down side, I still don't have a clear and useful picture. :( And based on what I know of the standard, it may be my TV doesn't have a PAL compatible mode or something.

 

EDIT: I'm following a lead to perhaps acquire a 14" TV that's PAL. It will require a transformer to use, but at least I could hook up to it directly.

 

I'm okay with a TV because by the look of things TV's are what 99'ers have been using pretty much forever outside of the states. Because there are no other options.



#41 apersson850 OFFLINE  

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Posted Fri May 17, 2019 9:43 AM

The RF modulator for European consoles is supposed to emit an antenna signal, tuned to UHF channel 36. That antenna signal should include both the image and the sound.

 

You can look at a picture of such a modulator. The channel number is printed on the label. This particular one has been modified to output composite video and sound on two separate coax ports (one BNC and one RCA connector).



#42 adamantyr OFFLINE  

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Posted Fri May 17, 2019 9:57 AM

The RF modulator for European consoles is supposed to emit an antenna signal, tuned to UHF channel 36. That antenna signal should include both the image and the sound.

 

You can look at a picture of such a modulator. The channel number is printed on the label. This particular one has been modified to output composite video and sound on two separate coax ports (one BNC and one RCA connector).

 

It's an unmodified PAL modulator, so it says it's tuned to channel 36 UHF on the label. As I switched the TV closer to 36 the sound changed as it got closer to the band. Channel 34 was the only one that rendered any image, the rolling black and white.

 

My VCR/TV is from the 90's so it may be one of those TV's that just doesn't work with the older standards. Unless someone has a better theory?



#43 apersson850 OFFLINE  

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Posted Fri May 17, 2019 11:27 AM

That shouldn't make any difference, provided the VCR works.

Inside such a modulator, it's usually possible to fine tune the channel it uses. That's intended for television sets with fixed channel steps, where tolerances may imply that the two devices can't perfectly match their channels. If the TV looks at channel 36.3 and the modulator outputs 35.8, some fine tuning is necessary.

I've never needed to do that, so I can't say for sure if, and then how, you do that with the TI modulator.



#44 mizapf OFFLINE  

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Posted Fri May 17, 2019 11:30 AM

You don't happen to have a newer flatscreen TV with analog tuner? The test that I made at the start of this thread was with a Samsung monitor/TV (LE19B450). Chances are that those devices are multi-norm.



#45 adamantyr OFFLINE  

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Posted Fri May 17, 2019 12:14 PM

That shouldn't make any difference, provided the VCR works.

Inside such a modulator, it's usually possible to fine tune the channel it uses. That's intended for television sets with fixed channel steps, where tolerances may imply that the two devices can't perfectly match their channels. If the TV looks at channel 36.3 and the modulator outputs 35.8, some fine tuning is necessary.

I've never needed to do that, so I can't say for sure if, and then how, you do that with the TI modulator.

 

There is no VCR here. Nothing worked with that, so I had to go to a TV I had that is ALSO a VCR but has an antenna in, so I could just directly hook up to it. There's no composite cable involved right now whatsoever.



#46 adamantyr OFFLINE  

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Posted Fri May 17, 2019 12:15 PM

You don't happen to have a newer flatscreen TV with analog tuner? The test that I made at the start of this thread was with a Samsung monitor/TV (LE19B450). Chances are that those devices are multi-norm.

I do, but reaching the antenna port would be a major hassle, and the TV is huge so it's not really going to show me how it looks in comparison to my regular TI monitor.



#47 adamantyr OFFLINE  

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Posted Fri May 17, 2019 1:02 PM

Some pics of it in action:

 

Attached File  20190517_115030.jpg   955.03KB   0 downloadsAttached File  20190517_115044.jpg   1.05MB   0 downloads



#48 mizapf OFFLINE  

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Posted Fri May 17, 2019 1:10 PM

Back in the 80es, my dad had adjusted one of his TV sets to be able to receive AFN television in Germany. On all other TVs, the picture was rolling because of the 60Hz, and it was black and white, and sound was missing, if I remember correctly, but on this one we could watch and listen, but in b/w only.



#49 adamantyr OFFLINE  

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Posted Fri May 17, 2019 1:56 PM

Back in the 80es, my dad had adjusted one of his TV sets to be able to receive AFN television in Germany. On all other TVs, the picture was rolling because of the 60Hz, and it was black and white, and sound was missing, if I remember correctly, but on this one we could watch and listen, but in b/w only.

 

Yeah, I'm guessing with older TV's, you NEED to have an actual PAL 50hz TV. Maybe a modern one would work, I'll test it sometime this weekend.

 

EDIT: Tested it, the modern TV doesn't have a sync issue, but there's no sound, it's black and white, and there's TONS of nasty artifacts going on, little blips and splotches all over. This picture looks better than it is.

 

Attached File  20190517_131425.jpg   706.79KB   0 downloads



#50 blackbox OFFLINE  

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Posted Fri May 17, 2019 3:10 PM

Using the TI PAL modulator...

About the time the TI came out TV sets sold in the UK began to work well with a either a 50Hz or a 60Hz signal, as the tv sets were able to lock onto the frequencies well. My present CRT tv set is perfectly happy with an input of 50 or 60Hz.

There was a long standing issue in the UK with television sets made for the UK market not working too well with the UK TI99/4a. You could tune the TI sound in perfectly OR you could tune the TV picture in well. To get something approaching good meant VERY fine tuning of the tv channel, and if you got the sound perfect with no hum, the picture was probably rolling or there was colour loss etc.

This was designed in by TI. The PAL modulators were made for European PAL. The BBC chose to have their own version of PAL for the UK standard and there was a wider audio bandwidth. Or to put it another way, on the TI modulators of the day the sound channel was too close to the picture channel to play nicely with UK tv sets....

The UK used PAL STANDARD I while Europe used PAL STANDARD B or G - B and G used different bandwidths but the distance between image and sound was the same. The BBC wanted better quality sound so the sound channel in standard I was 0.50 MHz adrift of Standards B and G.,

I suspect this may be your problem with the RF signal. There is no ready answer except to tweak the fine tuning on the tv set- most sets had a manual fine tune opton. And compromise. Most folks preferred a good picture.

Edited by blackbox, Fri May 17, 2019 3:13 PM.





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