Philips NMS 8220 (MSX2) - no video output via Scart

Resident (43)

04-03-2019, 12:20

Hi folks,
My long anticipated MSX2 system, a Philips NMS 8220, finally arrived !

But I have a problem. There is no display on my LCD flat screen -which only embeds a VGA connector. The screen itself works well of course...
In order to connect the screen, I have this setup :

I basically put 2 adapters on the Scart connector : one to route the audio to Jack (red), one to route the video to VGA (green). So :
- it initially reacts as if there was a signal, and only goes to sleep mode after a while. It also detects when I unplug the connector ;
- I tried with one adapter at a time: it doesn't change anything ;

I have a few questions :
- there are no beeps at bootup. should there be ?
- by the way, is there an integrated bipper/buzzer ? Or is it supposed to come out of the connector (which could explain why I don't hear anything) ?
- is there a manipulation for it to use the Scart connector ? because blue "monitor" port is obviously preferred.

Thanks a lot for any help !

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By Pentarou

Hero (563)

04-03-2019, 15:20

Does your LCD monitor support 15Khz signal on the VGA input?
What kind of cable is your SCART->VGA? Self built or what else?

By Hans41

Expert (71)

04-03-2019, 16:15

Sorry to hear you have difficulties getting video output on your monitor.

Is there someone you know who owns a tv with scart connector on which you can verify the scart connection of the nms8220 is functioning properly ?

I don't think you should hear beeps when booting this machine. If the 2nd rom is still there and you use ESC to skip the designer proggie, maybe ? I've removed that rom from my machine.

By Wlcracks

Hero (572)

04-03-2019, 16:37

It doesnt work at all if the monitor doesnt support 15khz 50hz. dont think it will on a vga connector, but hell maybe. This should be in the monitor user manual. Still tricky cause VGA uses seperate h and v sync.
Normally people use (expensive) scan converters and scalers.

By Grauw

Ascended (10821)

04-03-2019, 17:25

As said you can not use a passive cable unless the monitor supports a 15 kHz horizontal scan signal (VGA is normally 30 kHz), most modern monitors don’t, although perhaps few monitor-TV combinations do (but they likely already have a SCART input).

What you need to use is an active converter, for SCART to HDMI / DVI conversion there are various fairly cheap Chinese converters which give ok-ish quality (they introduce latency and perform bad deinterlacing), for high quality conversion the best option is the OSSC converter which is not cheap but gives a very sharp image and 0 latency.

For SCART to VGA conversion there are similar low quality Chinese converters, there are probably also high quality scan doublers but I can’t give any advice on those since I don’t have one of those myself, search for "scart to vga scan doubler" or something like that. They may be a bit harder to find since HDMI / DVI is more common nowadays.

p.s. Note that HDMI and DVI are compatible with just a small adapter plug, so a HDMI converter will also work on a DVI input.

By Tarnyko

Resident (43)

04-03-2019, 22:39

Hi,
Thank you all for your quick and kind replies !

Pentarou, Wlcracks, Grauw, so I need to support a 15 kHz signal coming from the MSX; shame on me for not knowing my basics !
This is the cable I used, it's definitely passive... I will follow your advice, although -Grauw- I have to say the OSSC converter is pretty expensive (even more than what I got my machine for, no kidding), so I'm gonna dig the web for a doubler.

EDIT : OMG, I didn't even realize these devices could be so rare & expensive !
Here is what I found so far : -1- , -2-, -3-. Even when it's in stock (it often isn't), it reaches the MSX itself in terms of price tag.

Hans41, thanks for reassuring me about the beeps. Just curious, what ROM are you talking about ? My 2 cartridge slots are free, though I guess you're talking about an internal chip, right ?

By Pentarou

Hero (563)

04-03-2019, 23:13

That cable looks sketchy (description says it's for mobile phones???). It doesn't say which way it should be used (SCART --> VGA or VGA-->SCART???), what signals it transmits or if there's a circuit inside for the sync separation.
The OSSC is overkill for most people, but Grauw gave also links for cheaper units. You could be Ok with the "cheap Chinese converters" since you will not need deinterlacing.
BTW. Device 3 that you linked is just a sync converter, won't help much if your monitor is still 31Khz+ only.

By Grauw

Ascended (10821)

04-03-2019, 23:48

Pentarou wrote:

You could be Ok with the "cheap Chinese converters" since you will not need deinterlacing.

I think it’s probably best to start out with one of those indeed, they’re so affordable that if you ever get something else down the line that you’ll have wasted a lot of money on it. Btw, don’t expect a better picture quality from a flat panel TV with a SCART input, it will have a similar chip inside as those Chinese converters.

Though from a quick search it seems SCART to VGA seems a lot harder to find… don’t you have a monitor with HDMI or DVI input? Even if you don’t I bet you can get one second hand for cheap. There are plenty of converters for that (many people with various SCART video equipment and HDMI TVs).

Just for the record, the issue with deinterlacing is that it applies it even if the signal from the MSX is an (uninterlaced) progressive scan signal… this can cause some visual artifacts on moving objects. Nothing too terrible, but I wanted to clarify what I meant there.

By Manuel

Ascended (19682)

04-03-2019, 23:46

I'd definitely try to get a CRT with SCART connector to test it on. And if you can't find that, a TV with SCART on it as native input. Just to test your machine. And then look into the cable details.

By Tarnyko

Resident (43)

05-03-2019, 00:52

Hey Manuel,
I may well live in France (where SCART was a norm under the name "Peritel"), those have become rare. I phoned a few friends, no luck yet; but you're right, it would clarify the situation.

Grauw, willing to be ready for anything, I ordered the following from Eternal China :
- SCART -> HDMI (active convertor/scaler) ;
- HDMI -> VGA/Jack (active convertor/scaler).
Not very elegant I admit, quality loss expected; but it should do the trick.

(PS Pentarou : well spotted, cable #3 was a trap for beginners - like me ^^)

By Wlcracks

Hero (572)

05-03-2019, 08:08

Now i am feeling old...

CRT are given away free on marktplaats.nl
maybe in your neigbourhood too?