Jump to content

Photo

New development: GTIA in CPLD


789 replies to this topic

#701 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Sun Jul 16, 2017 9:21 AM

Not to mention, these *are* atari *computers* we're talking about here, dunno why you are all trying to use them on TV's anyway ;)

 

So that's what I've been doing wrong  :ponder:   :rolling:

 

- Michael



#702 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Sun Jul 16, 2017 1:34 PM

I got this coming...

 

s-l1600.jpg

 

Hopefully this will work better doing PAL RGB from Sofia. Can anyone out there confirm doing the same?

 

- Michael



#703 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Mon Jul 24, 2017 5:51 PM

Sophia connected to Atari SC1224 'ST' RGB Monitor

 

Live picture 1088XEL in PAL Mode

 

HCMxGRn.jpg

 

This will not work from a standard Sophia board, since the SC1224 Monitor requires higher level signals than VGA (or likely other RGB monitors). The Sophia only puts out 0.75 volt RGB and CSYNC when set to RGB mode (at least my Sophia running the 'B' core did). The SC1224 requires 1 volt RGB and close to logic level CSYNC. So the first thing I did was change a resistor on the Sophia board to increase the video output from the ADV7125 Triple High-Speed Video DAC chip.

 

Increase Video Output Level Mod (opps I see there is an extra '2' shown for the monitor part number :P )

 

2lDYj23.png

 

 

Next we need a buffered logic level CSYNC to substitute for Sophia's low level one, so we'll steal that from the CD4050 chip on the A8.

 

TQVf0Nw.jpg

 

 

And assuming all the Mods were done correctly you should now see a beautiful full color display on the SC1224 Monitor coming from your Sophia upgraded A8. And depending upon what video mode you use on your A8 (NTSC or PAL), you might need to tweak some of the back panel controls for V and H Hold, and possibly Vertical Position and Height, as well as Horizontal Position. I have only tested this on the 'JVC' version of the SC1224, so I have no idea if it'll work correctly on either the Goldstar or the Samsung models.

 

Disclaimer: This Mod is done at your own risk, will probably violate any warranty you may have, and is not endorsed what-so-ever by Simius (creator of the Sophia board).

 

- Michael



#704 Mark loves Stella ONLINE  

Mark loves Stella

    Space Invader

  • 27 posts
  • Location:Concord, NC

Posted Mon Jul 24, 2017 8:53 PM

I got this coming...

 

s-l1600.jpg

 

Hopefully this will work better doing PAL RGB from Sofia. Can anyone out there confirm doing the same?

 

- Michael

If you have a VBXE installed and replace the NTSC Antic with a PAL Antic, it will work. I did this. I have only experienced a few PAL demos not working. But, so far, all PAL games work.



#705 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Mon Jul 24, 2017 11:13 PM

If you have a VBXE installed and replace the NTSC Antic with a PAL Antic, it will work. I did this. I have only experienced a few PAL demos not working. But, so far, all PAL games work.

 

That is very Interesting, but I'm actually running as a true PAL machine in every regard so all games and demos should work as they were meant to (fingers crossed).

 

My photo doesn't even do it justice as to how good this looks on the SC1224 monitor. There's just something about a CRT RGB monitor that is very difficult to match with an LCD. Now of course if we were talking HDMI that would be the ultimate, but we have yet to see native support for that in a real A8 machine. And with Sophia being about 1/2 the price of a VBXE (when factoring in shipping), it's really the best you are going to do at that price point. Now of course the VBXE has a few tricks up it's sleeve, but other than the 80 column mode, most of those tricks require specific software support to see them in action. And when considering how long the VBXE has been available, that support is still kind of sparse.

 

Since the 1088XEL doesn't have a CD4050 video/sync buffer chip, it needs to be implemented with a separate one transistor (Q11) buffer as shown in this schematic...

 

mhjB3kR.png

 

 

This circuit produces a 3.3 volt CSYNC signal, and is what I was using to generate the display I showed in the photo of the SC1224.

 

- Michael


Edited by mytekcontrols, Mon Jul 24, 2017 11:37 PM.


#706 tf_hh OFFLINE  

tf_hh

    Moonsweeper

  • 498 posts
  • Location:Germany

Posted Mon Jul 24, 2017 11:58 PM

This will not work from a standard Sophia board, since the SC1224 Monitor requires higher level signals than VGA (or likely other RGB monitors). The Sophia only puts out 0.75 volt RGB and CSYNC when set to RGB mode (at least my Sophia running the 'B' core did). The SC1224 requires 1 volt RGB and close to logic level CSYNC. So the first thing I did was change a resistor on the Sophia board to increase the video output from the ADV7125 Triple High-Speed Video DAC chip.

 

2lDYj23.png

 

 

Michael, cool stuff!

 

Also thanks for pointing out the resistor change. I´ve experienced several problems with Sophia and some monitors connected using the SCART interface (very common in Europe). Also I recognise the weak levels at RGB output lines. SCART also demands 1V levels. So this may be "the" issue. Will try it out...

 

:thumbsup:



#707 Simius OFFLINE  

Simius

    Moonsweeper

  • Topic Starter
  • 458 posts
  • Location:Warszawa, Poland

Posted Tue Jul 25, 2017 3:48 AM

SCART RGB signals are 0.7Vpp @ 75ohm. 1Vpp level is required on the CVBS input, because the SYNC pulses (0.3V) are added.

http://cncms.com.au/...rtconnector.pdf


Edited by Simius, Tue Jul 25, 2017 3:49 AM.


#708 tf_hh OFFLINE  

tf_hh

    Moonsweeper

  • 498 posts
  • Location:Germany

Posted Tue Jul 25, 2017 10:28 AM

SCART RGB signals are 0.7Vpp @ 75ohm. 1Vpp level is required on the CVBS input, because the SYNC pulses (0.3V) are added.

http://cncms.com.au/...rtconnector.pdf

 

Oops... my fault. Thanks for correction. But I will try it with smoother values for that resistor :)



#709 foft OFFLINE  

foft

    Dragonstomper

  • 637 posts
  • Location:Nyon, Switzerland

Posted Tue Jul 25, 2017 3:09 PM

SCART RGB signals are 0.7Vpp @ 75ohm. 1Vpp level is required on the CVBS input, because the SYNC pulses (0.3V) are added.
http://cncms.com.au/...rtconnector.pdf


On the eclaireXL we've been using the CDK3405 which is similar but cheaper to the ADV7125 I think.

RGB is great, though for composite I'm not sure if I need to boost composite beyond 0.3V sync + 0.7V for the signal. I tried it the 'Atari way' with stepped luma. Using 90/256 * 0.7v for the colour signal (fixed amplitude, phase shifted for hue) + brightness*11/256*0.7v for the luma. Still it seems not quite bright enough to me.

Anyway I'm just curious if you've tried composite from the Sophia?

#710 enito OFFLINE  

enito

    Chopper Commander

  • 208 posts

Posted Fri Aug 4, 2017 12:42 PM

Hi , still possible order a Sophia? and price? thx!!!!



#711 Simius OFFLINE  

Simius

    Moonsweeper

  • Topic Starter
  • 458 posts
  • Location:Warszawa, Poland

Posted Fri Aug 4, 2017 4:27 PM

On the eclaireXL we've been using the CDK3405 which is similar but cheaper to the ADV7125 I think.

RGB is great, though for composite I'm not sure if I need to boost composite beyond 0.3V sync + 0.7V for the signal. I tried it the 'Atari way' with stepped luma. Using 90/256 * 0.7v for the colour signal (fixed amplitude, phase shifted for hue) + brightness*11/256*0.7v for the luma. Still it seems not quite bright enough to me.

Anyway I'm just curious if you've tried composite from the Sophia?

 

CDK3405 is cheaper but I've more trust for Analog Devices. :)

I've not tried to make composite from Sophia because I don't like composite at all. I think a low quality interface isn't worth the time spent on it. Unless for fun.



#712 enito OFFLINE  

enito

    Chopper Commander

  • 208 posts

Posted Mon Aug 7, 2017 10:47 AM

Sophia board if possible connect to a sc1435? i have one of this, and have a db9 style connector if im not bad.

 

thx!



#713 GlowingGhoul OFFLINE  

GlowingGhoul

    Chopper Commander

  • 213 posts

Posted Mon Aug 7, 2017 10:59 AM

 

CDK3405 is cheaper but I've more trust for Analog Devices. :)

I've not tried to make composite from Sophia because I don't like composite at all. I think a low quality interface isn't worth the time spent on it. Unless for fun.

 

That's only because Europeans have no appreciation for the early games that used artifacting for color. Ultima III, Choplifter, David's Midnight Magic, are all monochrome with this board.


Edited by GlowingGhoul, Mon Aug 7, 2017 10:59 AM.


#714 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Sat Aug 19, 2017 10:06 AM

I've been using my Sophia board for driving into two different SC1224 ST monitors lately with a PAL setup, and although it looks very, very cool, and produces the best image I've seen thus far, the color pallete still appears to be not quite right. In particular light (pale) blues are not quite right, being more on the greenish side of things. So for instance, the normally light blue background in Basic looks more cyan, and in Star Raiders when you enable the shields it's light green instead of light blue. Is it just me, or are others seeing this as well? Keep in mind that I am using a PAL system, and that this has been verified on two different SC1224 monitors.

 

I'm also using the latest Sophia firmware revision.

 

- Michael



#715 flashjazzcat OFFLINE  

flashjazzcat

    Quadrunner

  • 12,755 posts
  • Location:United Kingdom

Posted Sat Aug 19, 2017 10:33 AM

My stock PAL hardware all produces cyan backgrounds. I've tested a Sofia here in RGB mode and it looks right to me (identical to VBXE).

#716 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Sat Aug 19, 2017 11:18 AM

My stock PAL hardware all produces cyan backgrounds. I've tested a Sofia here in RGB mode and it looks right to me (identical to VBXE).

 

I guess all is ok then  :)

 

- Michael



#717 Simius OFFLINE  

Simius

    Moonsweeper

  • Topic Starter
  • 458 posts
  • Location:Warszawa, Poland

Posted Sun Aug 20, 2017 10:50 AM

Firmware update.

1. Our5oft issue fixed.

2. bit4 PMCTL controls additional color in hi-res mode.

3. VSYNC output comes back in rev.B.

 

Please report any comments.

Attached Files


Edited by Simius, Sun Aug 20, 2017 11:01 AM.


#718 towmater OFFLINE  

towmater

    Moonsweeper

  • 413 posts

Posted Tue Aug 29, 2017 7:11 PM

Forgive me, Simius, but I couldn't make it through all 30 pages of this thread to find out... is this a thing that I can buy for a 1200xl that will give me rgb output? (I was tuckered out by page 27.) I don't want to hack up the motherboard to do a composite mod, which goes against my "first do no harm" retro hardware edict.



#719 ApolloBoy OFFLINE  

ApolloBoy

    Quadrunner

  • 5,696 posts
  • Location:San Jose, CA

Posted Tue Aug 29, 2017 7:33 PM

Forgive me, Simius, but I couldn't make it through all 30 pages of this thread to find out... is this a thing that I can buy for a 1200xl that will give me rgb output? (I was tuckered out by page 27.) I don't want to hack up the motherboard to do a composite mod, which goes against my "first do no harm" retro hardware edict.

It should work on a 1200XL just fine, it even works on a 5200 without any problems.

#720 Simius OFFLINE  

Simius

    Moonsweeper

  • Topic Starter
  • 458 posts
  • Location:Warszawa, Poland

Posted Tue Aug 29, 2017 11:25 PM

is this a thing that I can buy for a 1200xl that will give me rgb output?

 

Yes, it is.



#721 Philsan OFFLINE  

Philsan

    River Patroller

  • 3,406 posts
  • New Orleans Saints Super Bowl XLIV Champions
  • Location:Switzerland

Posted Wed Aug 30, 2017 12:56 PM

Firmware update.

1. Our5oft issue fixed.

2. bit4 PMCTL controls additional color in hi-res mode.

3. VSYNC output comes back in rev.B.

 

Please report any comments.

I tested new firmware and now Our5oft demo is perfect.

Thank you very much Jacek!

 

Can you please explain:

bit4 PMCTL controls additional color in hi-res mode.



#722 Lavalamp OFFLINE  

Lavalamp

    Space Invader

  • 19 posts
  • Location:Wellington, New Zealand.

Posted Wed Aug 30, 2017 5:15 PM

H

 

 

Yes, it is.

 

 

Hi , is this still around, where can I purchase one?  :)



#723 towmater OFFLINE  

towmater

    Moonsweeper

  • 413 posts

Posted Thu Aug 31, 2017 9:33 AM

I wish the first message in the thread could be updated with ordering info, but as far as I can tell the "Sophia" costs $55 plus shipping from Eastern Europe, order by PM'ing Simius. I gather the thing goes out to a db-9 connector and is suitable for a Scart-to-hdmi conversion box if you make a Scart cable for it.



#724 mytekcontrols ONLINE  

mytekcontrols

    River Patroller

  • 2,193 posts
  • Location:Santa Rosa, CA

Posted Thu Aug 31, 2017 1:12 PM

H

 

 

 

Hi , is this still around, where can I purchase one?  :)

 

I hope he is around, and keeps selling this board, because the 1088XEL has been modeled to allow this to be dropped in and directly drive Atari SC1224 monitors (well with a very small mod, change a resistor and add one more crimp connector on the existing cable). Works great  :thumbsup:

 

- Michael



#725 towmater OFFLINE  

towmater

    Moonsweeper

  • 413 posts

Posted Thu Aug 31, 2017 10:03 PM

I just sent an order inquiry, I gather I need to start reading this whole thread, to find out what I'm in for. I'm hoping I won't need to cut holes in the case or pull out existing components, although some soldering of wires might be OK.






0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users