Atari 1040STF monitor HDMI connection

[+RSA]

I grew up with an Atari 800XL but I was always curious about the ST line. I was saving money to get one but then the PC era started and I went that route instead. Now, decades later, I finally fulfilled that childhood dream and got a 1040 STF!

 

What surprised me is how hard it seems to be to get it connected to a modern monitor. For my 8 bit machines, I use a Retroscaler 2x which accepts composite and s-video connectors. It also accepts RGB (three RCA-like plugs) but I could only find an Scart cable for ST RGB signals, which I got from Cool Novelties. My plan was then to use this Scart scaler to link the ST to my monitor's HDMI port: https://www.amazon.com/TAIPOXUN-Converter-Adapter-Support-Coaxial/dp/B08KFYZ9C1/ref=mp_s_a_1_3_pp

 

Considering that the same cable + scaler combo is being sold as an ST to HDMI solution, I felt it should work: https://www.ebay.com/itm/266818858827. However, my monitor does not get any signal coming from the scaler (the scaler is powered on). I have tinkered with the scaler's buttons but still no signal. I also tried it on an old LCD TV and no signal either. I've read about the ST's 15MHz frequency being an issue but that a scaler shouldn't have trouble with that.

 

I also connected my speakers to the scaler's audio out to see if I could hear anything, but I heard nothing. Does the ST make any sounds when booting up? Does it load GEM immediately? I hear it trying to access the floppy drive for a while after powering it on but I don't have any floppies.

 

My search in AA and the Internet hasn't given me any other clues.

 

What do you folks think could be the issue, and what can I do to troubleshoot this? The ST is supposed to be working. Perhaps find a VGA cable and an old monitor to see if the machine is ok? Or a different Scart scaler? I'm unable to find an Scart to RGB adapter (three plugs) but I do seo Scart to s-video adapters I could try.

Edited July 15 by RSA

[snarkdluG]

The ST makes no sound at boot. It can take up to a minute to get to desktp if you don't have a floppy. But it should make click sound when key is pressed on the keyboard or if you detach the keyboard from the motherboard.

 

A diagnostic cartridge and a null modem cable to another computer with a terminal program on it can tell you if it is working as well. The scaler you use should work, it is pretty common to use that one.

[+RSA]

This cartridge: https://www.ebay.com/itm/204364067459?

Is the cartridge necessary to connect via the null modem?

[tjlazer]

The cartridge is merely the way to load the diagnostic program on the ST.

[+RSA]

Update: I connected my speakers to the audio output on the scaler and I can hear the clicks when pressing keys, which is a good sign. Still no hdmi signal recognized by my monitor or tv.

 

I also tested that the scaler is at least able to output hdmi by connecting my laptop to it (the scaler has an hdmi in port). That works fine.

 

So, the issue is with either the ST's video out or the cable's video wires or the scart connectors (either the cable's plug or the scaler's jack).

 

Has anyone experienced an issue like this with an rgb scart cable or scaler?

Edited July 16 by RSA

[oracle_jedi]

Do you know if your 1040ST has composite output?  

 

Does it have a TV modulator?

 

Quite a lot of 1040STs did not have composite output.  Only RGB/HV.  The SCART standard does NOT support RGB/HV, but rather RGBS.  The S in that acronym is for composite sync, which would be carried on the ST video connector pin 2, and which in SCART would be carried on pin 19 or 20.  The scaler link shown at Ebay expects RGBS - as evidenced by the statement it is for a 520STFM/1040STFM.   

 

Your Retroscaler 2x you stated has 3 RCA jacks for RGB, so that's probably RGsB, with "sync on green".  Although it might even be YCbCr, which is yet another option.

 

If your 1040ST does not have the CSYNC line, there are mods out there to add it.  IIRC, its a simple enough mod to do.

 

HTH

 

 

[Forrest]

FYI for about $15 more than the ST diagnostic cartridge, you can buy a SidecarTridge https://sidecartridge.com/, which will download and run the diagnostic cartridge and do a lot more such as download and run games from an internet database.

[+RSA]

I wasn't aware of these variants of RGB. Interesting new topic for me. Thanks for bringing it up, @oracle_jedi and for all the info.

1 hour ago, oracle_jedi said:

Does it have a TV modulator?

It's an STF, no RF modulator.

 

1 hour ago, oracle_jedi said:

Do you know if your 1040ST has composite output?  

I have no idea if it has composite video output. Or do you mean composite sync?

 

To check CSYNC, is it as simple as testing for any signal on pin 2 on the monitor jack or 20 on the scart plug?

 

Interestingly, I got the STF from the same vendor who offers that cable+scaler at https://www.ebay.com/itm/266818858827. He used that combo to test the machine and posted pictures. Given what you mention about scart using RGBS, the monitor port must have CSYNC already. And that in turn suggests that either my cable from cool novelties or the scaler are at issue. (Hopefully the ST wasn't damaged in transit; at least I can hear the key clicks on the audio out.)

[oracle_jedi]

 

"I have no idea if it has composite video output. Or do you mean composite sync?"

 

For our purposes they are the same.  Monitor cables that need CSYNC usually tap pin 2 for composite video which carries the CSYNC signal along with the combined chroma/luma signal.

 

Which cable did you buy?

 

Cool Novelties sells an Atari ST to SCART cable specifically designed for ST systems that don't have CSYNC/Composite Video on Pin 2.  HYSNC and VSYNC can be easily combined to create a CSYNC, and I am guessing that is what this cable does.

 

https://coolnovelties.co.uk/coolnovelties/atari-st-video-cables/267-atari-st-for-early-models-with-sync-combination-quality-rgb-scart-video-cable.html

 

They state this is for the original 520ST (not 520STm), but many early 1040STs were shipped without composite video as well.

 

As for testing I am not sure.  I use an ST to Composite video cable and my Commodore 1084, but I am guessing you have neither the cable nor a suitable composite monitor.

 

HTH

 

 

[+RSA]

9 hours ago, oracle_jedi said:

Cool Novelties sells an Atari ST to SCART cable specifically designed for ST systems that don't have CSYNC/Composite Video on Pin 2.  HYSNC and VSYNC can be easily combined to create a CSYNC, and I am guessing that is what this cable does.

 

https://coolnovelties.co.uk/coolnovelties/atari-st-video-cables/267-atari-st-for-early-models-with-sync-combination-quality-rgb-scart-video-cable.html

Nice. Now I understand why they offer this other cable, and a likely reason why my cable+scaler combo is not working.

[bfollowell]

Yes, STFs do not have the CSync signal. The components to create it were not installed, though they are silk-screened onto the motherboard and the holes are there. You can add them for about $10 in parts if you have a soldering iron.