US TI-99/4a & Commodore 1702 monitor

[palmheads]

Hey all

 

I've got a Commodore 1702 monitor here at home. Am in New Zealand, but I think if I got a US TI-99/4a the whole PAL/NTSC issue goes out the window huh with the appropriate monitor cable. Is my assumption correct?

 

I may even have a compatible monitor cable already, as my C64 & Sega SC3000H both connect to the 1702.

 

However, looks like cables like this:

http://www.ebay.com/itm/Atari-Commodore-TI-99-4A-Performance-Series-Color-Composite-Video-Audio-Cable-/231489379832?pt=LH_DefaultDomain_0&hash=item35e5d79df8

 

May be all I need.

 

Its quite hard to see UK TI's on ebay, and very few people seem to ship overseas from there. Loads of US TI's though.

 

cheers

Daryn

[+Ksarul]

For PAL model /4A computers, you might also want to look on the German, Dutch, or Austrian TI sites as well. If you're really adventurous, you could also check out the Mercado Libre site in Argentina. As to making things work with the 1702. Note also that the PAL 99/4A has a 6-pin DIN socket, while the NTSC version has a 5-pin. The cables are not interchangeable, but I've seen new-manufactured PAL cables show up on eBay in Great Britain pretty regularly.

 

As to 1702 compatibility--the output isn't Chroma/Luma, so you can't use the rear connectors. The composite ouput is different for PAL and NTSC models, of the TI, so you'd have to have a 1702 with a matching signal input type (PAL or NTSC composite) on the front connectors. I ran into this issue regularly in Germany many years ago. . .

[UKRetrogamer]

I had a Component cable from RetroComputerShack but Ian has since withdrawn this item from from his shop.

 

I've modified my PAL modulator, picking up two points from inside to provide Composite output. I use my modified modulator with a Commodore 1701 monitor.

 

Depending on your modulator (Aluminium or plastic), the modification differs slightly. The plastic modulators require addition of a few electronic components whereas the (older?) Aluminium one requires only soldering a pair of phono cables to a few points inside the case.

Edited February 28, 2015 by UKRetrogamer

[+Schmitzi]

I have about 10 of this cables, PAL and NTSC, from different sellers on eBay,

tested them at different consoles (US & EU) and Monitors, and NONE of them is working.

after half a year I am still sitting in front of this bad picture

[+Ksarul]

I bought the cable my boys are using for their machine from the same seller as the auction in post one goes to--it works nicely. The real problem in getting the cable/composite monitor issue resolved is getting matching components from end-to-end (PAL or NTSC). Usually, the cables are good for the type of monitor/market they were designed for--and the same goes for the rest of the components. If you've been buying stuff from all over the world (like I do), I just make sure I have enough parts from one output/input style to build a complete system (and I mark the exceptions (like SECAM stuff) so that I don't forget). Luckily, Analog RGB doesn't have the multi-system issue--as long as you have the right sync signaling, it works.

[+Schmitzi]

yes, confirmed, I also make sure that I have enough parts :)

 

(but I expected that the PAL-like-Cable would run on 6-pin-TI with EU-TV-Display.

but, also, I don´t see a problem for me at this point as I save this cables

for later, and think that the solution will come up later, for sure the error is on me

 

Maybe, in this case, it is an issue with my display, which tells me "wrong format"

(The latest seller on eBay is very helpfull, still have to give him some more info today)

[+Ksarul]

Try the 6-pin cable to the 2 RCA jacks (one video and one sound) and use the DVD input. . .

[oracle_jedi]

I've got a Commodore 1702 monitor here at home. Am in New Zealand, but I think if I got a US TI-99/4a the whole PAL/NTSC issue goes out the window huh with the appropriate monitor cable. Is my assumption correct?

 

I may even have a compatible monitor cable already, as my C64 & Sega SC3000H both connect to the 1702.

 

 

Is your 1702 a U.S. spec monitor that takes NTSC, or a PAL 1702?

 

If it is a NTSC unit, then yes, a U.S. 99/4A will work great, but will obviously need a voltage converter for New Zealand, or a local 230V TI power supply. You are right that the monitor cable from a Commodore 64 or Sega SC3000H should work fine. I am assuming your cable is the 5-pin version, and not the 8-pin one used on later Commodore 64s.

 

If you have a PAL 1702 and you did get a U.K. spec TI99/4A it still would not work.

 

The PAL 99/4As used the TMS9929A chip which did not produce composite output. The 6-pin plug on the unit outputs an RGB style signal that is converted to RF by the modulator. There used to be a mod that allowed you to take composite video from inside the modulator, but I cannot find it now.

[+Schmitzi]

Hi,

 

OK, I did some more trying, but no result. Yes to Ksarul for connecting and choosing AV,

(DVD gives no reaction as there is a DVD-drive inside the TV

 

Here are some pics for the latest tested cable, with 5 jacks.

YES, I know this should be unnecessary, I think that cannot work as

there are three connectors for one graphic-AVIN, and I just plug in ONE of them to AV-IN

 

But I just post that.

 

The last 2 pics are from an US-Console, connected with a simple OLD-SCHOOL (RGB?)-Cable,

which just has 2 connectors, Sound and video. But this gives me also a not so good screen,

yes, it is sharper, but there is some issue with the contrast on the characters on screen.

Hope you can recognize that in the Pics.

I have tried to name the Pics very good, as AA struggles them a bit after uploading here.

 

If I connect this simple and old-school US-cable (2 jacks) to the original old TI-CRT-Monitor,

all is fine. Maybe I try this again on my LCD, with a bit adjusting the screen-parameters

 

But at least, wanted to get this newer cable running.....

I will let you know.

 

Thanks for patience

Ralf

 

[+Ksarul]

The black-and white screen from your GREEN input is the usual response when you send an NTSC composite signal through a PAL composite monitor. Note that it is nice and crisp. The artifacting in your input from the old school cable isn't coming from the TI or the cable--it is the monitor. Looking at what it did with your red/green/blue tests, I would say that it is having trouble syncing the color output to the TI input signal. You might be able to tweak it to get things better in alignment--if you're lucky. I still use a massive, old-school CRT just because of the fact that there are fewer issues with them. . .at least until my last CRT dies on me.

[palmheads]

 

Is your 1702 a U.S. spec monitor that takes NTSC, or a PAL 1702?

 

If it is a NTSC unit, then yes, a U.S. 99/4A will work great, but will obviously need a voltage converter for New Zealand, or a local 230V TI power supply. You are right that the monitor cable from a Commodore 64 or Sega SC3000H should work fine. I am assuming your cable is the 5-pin version, and not the 8-pin one used on later Commodore 64s.

 

If you have a PAL 1702 and you did get a U.K. spec TI99/4A it still would not work.

 

The PAL 99/4As used the TMS9929A chip which did not produce composite output. The 6-pin plug on the unit outputs an RGB style signal that is converted to RF by the modulator. There used to be a mod that allowed you to take composite video from inside the modulator, but I cannot find it now.

 

 

Ah interesting! Thanks everybody for all the information

 

One of the guys at work has a PAL TI - I think I can borrow it & see what does/doesn't happen.

 

Will also have a close look the 1702 - I'm pretty sure it would be a PAL one.The C64 it came with was a NZ one.

 

cheers

Daryn

[palmheads]

For PAL model /4A computers, you might also want to look on the German, Dutch, or Austrian TI sites as well. If you're really adventurous, you could also check out the Mercado Libre site in Argentina. As to making things work with the 1702. Note also that the PAL 99/4A has a 6-pin DIN socket, while the NTSC version has a 5-pin. The cables are not interchangeable, but I've seen new-manufactured PAL cables show up on eBay in Great Britain pretty regularly.

 

As to 1702 compatibility--the output isn't Chroma/Luma, so you can't use the rear connectors. The composite ouput is different for PAL and NTSC models, of the TI, so you'd have to have a 1702 with a matching signal input type (PAL or NTSC composite) on the front connectors. I ran into this issue regularly in Germany many years ago. . .

 

Cheers Ksarul, will do some digging on my 1702. Am sure it is a PAL one. Sounds like this might not be as easy as first thought

 

cheers

Daryn

[carlsson]

As far as I know, the parameters should boil down to something like this:

 

US TI-99/4A - has composite video output as mentioned, shares most of the pinout with VIC-20, Commodore 64, Atari 8-bit, Spectravideo etc, sometimes referred to as an American standard. Cables meant for the Sega SC-3000, Master System and first gen Mega Drive probably should be avoided, as they have the audio signal on the same pin as the first bunch, but they use pin 1 for video which happens to be a +12V signal from the US 99/4A, and it might not be nice to feed your TV 12V when it expects at most 1V.

 

PAL TI-99/4A - has component video output as possibly mentioned, 6-pin DIN to not confuse with the 5-pin layout. In theory you should be able to connect this to a modern TV that takes component input, not sure if you need additional components to enhance the signal.

 

Commodore 1702 - available in both PAL and NTSC versions, usually not able to display a colour picture in the other format.

 

Commodore 1084 - ditto, plus that those tend to have RGB inputs. Not that it matters a lot with the TI, as it outputs component video and you need a converter circuit to go from component to RGB.

 

Schmitzi: Do you have a multimeter or another tool so you can measure which pin on the 6-pin DIN goes to each RCA plug? If you get the cable(s) measured, they can be verified vs pinouts and it is easier to tell which plugs should be connected where. It is possible too that your ground signal is on the wrong pin, i.e. if the cable has five RCA plugs, it uses one of the six pins on the DIN connector for ground, but it might not be the same pin as TI used for ground. In the case of the PAL 99/4A, the middle pin 6 is the ground.

 

Also, since the TI only outputs mono sound, you should not need to have both plugs into the audio inputs. One of those inputs might be B-Y, R-Y, Y, +12V or GND.

[oracle_jedi]

The following video shows how to get composite video from a PAL TI99/4A.

 

 

If you have a PAL 1702, then you will need a PAL TI99/4A and this mod to get a colour picture.

 

As stated, if you plug a U.S. NTSC 99/4A into a PAL 1702, you will get a monochrome picture.

[Asmusr]

I tried to do this mod, but it wasn't at easy as the video shows. Firstly I couldn't manage to remove the PCB from the case no matter what I did. Secondly when I had finally managed to solder on the wires with the case on, the TV picture was flickering (falling over every second or so). I then tried on a second modulator with just alligator clips, but got the exact same picture problem. Perhaps an issue with my TV, but it works fine with other composite video sources.

[UKRetrogamer]

That's the mod I did. IIRC, it can be done without removing the case from the modulator.

 

On my current HD TV, I get no picture at all but the same modified RF modulator gives a perfect colour composite picture on my Commodore 1701 monitor.

 

I'm convinced modern TVs aren't as receptive to signals from old computers as the TVs released around the same time.

[Tursi]

They aren't. Old TVs just scanned what you sent them. Modern TVs have to digitize the signal, and it seems there are a few common chipsets that don't like half-frame video. It's definitely not TI specific, if the TI fails all my classic systems fail.

[+Schmitzi]

 

Schmitzi: Do you have a multimeter or another tool so you can measure which pin on the 6-pin DIN goes to each RCA plug? If you get the cable(s) measured, they can be verified vs pinouts and it is easier to tell which plugs should be connected where. It is possible too that your ground signal is on the wrong pin, i.e. if the cable has five RCA plugs, it uses one of the six pins on the DIN connector for ground, but it might not be the same pin as TI used for ground. In the case of the PAL 99/4A, the middle pin 6 is the ground.

 

Also, since the TI only outputs mono sound, you should not need to have both plugs into the audio inputs. One of those inputs might be B-Y, R-Y, Y, +12V or GND.

 

yes, thanks, I will do that next days and will let you know here.....

Maybe its time to launch my F18A ?

Edited March 2, 2015 by schmitzi

[ti99iuc]

The following video shows how to get composite video from a PAL TI99/4A.

 

If you have a PAL 1702, then you will need a PAL TI99/4A and this mod to get a colour picture.

 

As stated, if you plug a U.S. NTSC 99/4A into a PAL 1702, you will get a monochrome picture.

 

About the known mod for the PAL Modulators PHA2030/PHA2036 in matal/plastic cases, you can check >>HERE<< also

 

anyway the easy mod for the metalcase could be not 100% compatible with commodore's monitor and it not so good for the LCD.

[+Schmitzi]

oh yes, but this work is nothing for me.... it would endup in a dark desaster

Anybody sells this modded parts maybe ?

[carlsson]

I believe your green plug should go into the Y input, the red plug that gave a black and white image into either Pb or Pr, and then you have the other red plug or the white plug, that both used to be plugged in as audio, of which one should go into the other Pb/Pr input. The blue plug makes me think it contains 12V so you should probably leave it alone.

 

If you've got a game or something else that makes sound on startup, you should quickly be able to identify which plug has mono audio. If you just plug in one channel - can't recall if it is left or right - the TV will default to it being a mono input so you don't have to worry about feeding a stereo sound signal.

Edited March 4, 2015 by carlsson

[palmheads]

Just spent way too much on a PAL Ti-99/4a from Germany on ebay!

 

I know for sure my Commodore 1702 is PAL.

 

So guess will be buying some beers for one of my soldering hobby friends to modify the Modulator for me! haha

 

God I love vintage computers - can't wait until it arrives!

 

cheers

Daryn

[palmheads]

Hi all

 

Came up with this interesting solution (almost by accident!) for connecting my PAL TI to a PAL Commodore 1702 monitor with no mods.

 

I thought I'd forget completely about trying to connect to the 1702, & had an idea to search for a portable DVD player with a PAL TV tuner. Sure enough, I found one. Wasn't sure if it would work, but was cheap enough so went ahead & purchased it.

 

http://www.amazon.com/gp/product/B008HYWFA4?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00

 

Arrived today. Plugged it into the TI, manually tuned it in. It worked!

 

Then I realised in the package of the DVD players, they had cables for AV out with the 3 colour vid/sound etc plugs. Plugged those into the 1702 monitor, and that worked also!!!

 

So now have this interesting set-up with the TI displaying on both a portable DVD player and the 1702 monitor. See attached picces.

 

cheers

Daryn