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Sophia rev.C - DVI board

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12 hours ago, mytek said:

Did you try swapping out a 74F08 for the 74LS08? I know you probably did, but just in case you didn't, it might be worth a try.

I didn't, since I had convinced myself this was a 'warming up' issue, but I'm going to try a different CPU, GTIA, etc, along with the ICs you suggest. This would of course be a good idea if the issue is indeed Phi2 related.

 

EDIT: Synertek CPU fixes the player/missile garbage problem, but picture still periodically disappears, and for much longer periods than with the original CPU. But when it comes back, there's no junk.

Edited by flashjazzcat

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27 minutes ago, flashjazzcat said:

EDIT: Synertek CPU fixes the player/missile garbage problem, but picture still periodically disappears, and for much longer periods than with the original CPU. But when it comes back, there's no junk

It would be fascinating to probe that board with a scope and compare the waveforms of Phi2 coming out of each CPU and then what it looks like coming out of the buffer logic. 

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18 minutes ago, DrVenkman said:

It would be fascinating to probe that board with a scope and compare the waveforms of Phi2 coming out of each CPU and then what it looks like coming out of the buffer logic. 

Indeed. And I accept Oscilloscopes by way of YouTube channel/website donations. :)

 

Tried a number of chip swaps, anyway, and nothing fixes it. So it looks like different Sophia firmware is the way to go, as soon as I can get hold of the correct crimp connector for my USB Blaster without incurring fifteen quid in shipping costs from a parts vendor.

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10 minutes ago, flashjazzcat said:

Indeed. And I accept Oscilloscopes by way of YouTube channel/website donations.

If I win the lottery this weekend, you’re on. :) 

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On 9/25/2019 at 8:16 AM, flashjazzcat said:

Tried a number of chip swaps, anyway, and nothing fixes it. So it looks like different Sophia firmware is the way to go, as soon as I can get hold of the correct crimp connector for my USB Blaster without incurring fifteen quid in shipping costs from a parts vendor.

I'm watching your new video this afternoon Jon and really enjoying it as usual - love the Austin Powers interlude but sorry to hear why it was warranted! But the "Aw, shit. Here we go again ..." bit from GRAND THEFT AUTO: SAN ANDREAS was awesome. :) Glad reprogramming the SOPHIA got things sorted out. 

 

I'll have to keep this info tucked into the back of my head - I still plan to put a SOPHIA DVI into my 1088XEL. 

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On 9/25/2019 at 3:16 PM, flashjazzcat said:

Tried a number of chip swaps, anyway, and nothing fixes it. So it looks like different Sophia firmware is the way to go, as soon as I can get hold of the correct crimp connector for my USB Blaster without incurring fifteen quid in shipping costs from a parts vendor.

 

Sorry, I´m late to this party 😃

 

Did you exchange the Delay Line IC (CO60472)? I´ve had similiar problems with the Sophia RGB and VBXE, too. Stock video works fine, even with UAV or any other mod, but FPGA based video emulators makes woes. After hours of investigation with a logic analyzer and scope I found out, that the Delay Line has wrong delay times at two outputs. This causes the CAS and RAS timing slightly different than standard, we´re talking only about 30-40 nanoseconds. For me the conclusion was, that the slow old chips aren´t affected by this, but the very fast sampling FPGA read wrong infos, because the RAMs switched already to another output state. The system I have had for repair makes more trouble, not only PMG, but mostly. A new Delay Line cures all.

 

It´s worth a try I would say... alternative is to try a VBXE in this system.

 

 

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5 hours ago, tf_hh said:

Did you exchange the Delay Line IC (CO60472)? I´ve had similiar problems with the Sophia RGB and VBXE, too.

I didn't think to try that, but the older Sophia firmware Simius sent me seems to work perfectly well on this machine, so I was satisfied with the fix. You can see the testing procedure towards the end of this video:

 

 

5 hours ago, tf_hh said:

After hours of investigation with a logic analyzer and scope I found out, that the Delay Line has wrong delay times at two outputs. This causes the CAS and RAS timing slightly different than standard, we´re talking only about 30-40 nanoseconds. For me the conclusion was, that the slow old chips aren´t affected by this, but the very fast sampling FPGA read wrong infos, because the RAMs switched already to another output state. The system I have had for repair makes more trouble, not only PMG, but mostly. A new Delay Line cures all.

That's most interesting. The problem as observed in the video is apparently caused by an alteration to the original Sophia firmware intended to account for a timing skew caused by the Antonia 65C816 board. Obviously it was assumed that the augmentation would likely have no negative effects on stock machines, but in this case there was a problem. At least if the owner - following prolonged use of the machine - discovers some lingering issues, thanks to your analysis of similar problems, perhaps he can try swapping the delay line IC. :)

5 hours ago, tf_hh said:

It´s worth a try I would say... alternative is to try a VBXE in this system.

Thankfully we ended up with a solution which made such drastic action unnecessary. :) I have to say I never experienced any issues at all when installing VBXEs, but Sophia's pixel clock is pretty high and I imagine this makes things quite sensitive to external disturbance.

Edited by flashjazzcat
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1 minute ago, flashjazzcat said:

At least if the owner - following prolonged use of the machine - discovers some lingering issues, thanks to your analysis of similar issues, perhaps he can try swapping the delay line IC

The delay line is not a standard part, is it? In other words, is there a source for replacement other than Best Electronics?  

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1 minute ago, DrVenkman said:

The delay line is not a standard part, is it? In other words, is there a source for replacement other than Best Electronics?  

I believe so. Or a donor machine, of course.

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On 10/1/2019 at 3:06 PM, DrVenkman said:

The delay line is not a standard part, is it? In other words, is there a source for replacement other than Best Electronics?  

 

Maybe B&C has some, also, but it´s a special part. Some years ago I found a schematic from an unknown author with a discrete reproduction of the Delay Line:

 

delaylin.gif.082c9b813b60064d20ef02bcfcfca6d4.gif

 

I don´t know if anybody has built and successfully use such a substitute. But, it´s not really needed. If no Delay Line is availible, just replace all 74s parts incl. delay line around the DRAM control circuit, use one SRAM and you´re fine. Same way like I did in my 600XL expansion, Mytek did it in the 1088XEL/XLD or Lotharek with his SRAM module and Freddie replacement.

 

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Decided to redo Ron's DVI connector, soldering the DVI adapter to the motherboard GND layer (unfortunately it didn't dawn on me that the vias on the adapter perfectly line up with the RF modulator holes until too late: I had already precisely aligned the hole on the back of the case; no matter since it is still rock-solid), and using a Coca-Cola can as a blanking plate:

 

IMG_20191004_113724239.thumb.jpg.506ea9d4ca24d7b504e19ed45d7e350d.jpgIMG_20191004_113710063.thumb.jpg.4f2a565bbf81baad683fbbda6b64be09.jpgIMG_20191004_130548291.thumb.jpg.3c01871f4bdef78f7500df4e26493f34.jpgIMG_20191004_130504236.thumb.jpg.73b2e59cf15722235da667fd8916e81c.jpg

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3 hours ago, flashjazzcat said:

...IMG_20191004_113710063.thumb.jpg.4f2a565bbf81baad683fbbda6b64be09.jpg

What do you use to make the cuts so smooth and neat? It doesn't look like a dremel...

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14 minutes ago, Frankie said:

What do you use to make the cuts so smooth and neat? It doesn't look like a dremel...

Careful use of a flat file, and once done, use a tiny bit of acetone on a q-tip.  It melts / seals the plastic where the filing has been done.  Biggest thing here for all of this, is patience!

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Don't forget tremendous skill and natural flair. :)

 

But yes: I usually only use the dremel to get rid of large chunks of plastic, then finish as described above.

 

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On 10/2/2019 at 8:02 AM, tf_hh said:

 

Maybe B&C has some, also, but it´s a special part. Some years ago I found a schematic from an unknown author with a discrete reproduction of the Delay Line:

 

delaylin.gif.082c9b813b60064d20ef02bcfcfca6d4.gif

 

I don´t know if anybody has built and successfully use such a substitute. But, it´s not really needed. If no Delay Line is availible, just replace all 74s parts incl. delay line around the DRAM control circuit, use one SRAM and you´re fine. Same way like I did in my 600XL expansion, Mytek did it in the 1088XEL/XLD or Lotharek with his SRAM module and Freddie replacement.

 

That schematic doesn't seem to have an obvious input, though "pin 1" at least matches the datasheet.  Anyway, something like the DS1100Z line made by Maxim could be adapted using a SMT to DIP adapter board that connects the pins as required.  Of course it would help to know what the total delay time of the chip is supposed to be, and PCA seems to be so ashamed of making the EP8212 that they've stricken it completely from their catalog.  All the other numbers from EP8200 to EP8223 are present and accounted for.

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Hello ChildOfCv

On 10/4/2019 at 8:22 PM, ChildOfCv said:

Of course it would help to know what the total delay time of the chip is supposed to be ...

 IIRC the delay times are in the original Atari schematics of the 600XL and 800XL.  Which you can find on my site (docs page).

 

Sincerely

 

Mathy

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7 hours ago, Mathy said:

Hello ChildOfCv

 IIRC the delay times are in the original Atari schematics of the 600XL and 800XL.  Which you can find on my site (docs page).

 

Sincerely

 

Mathy

Wow, no wonder the chip isn't available.  Those timing numbers have no regularity about them.  Any replacement will have all the timing outputs as multiples of some constant.

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Okay, I'm looking at ordering a 2nd Sophia DVI card.  The 1st one I bought was programmed for 1280x1024 resolution (5:4 aspect ratio).  I'm thinking of going with the 1536x960 resolution (16:10) as I'll be connecting it to a 4K TV with a 16:10 aspect ration.  Which resolution/aspect ratio should I choose for my TV?  FWIW, the 5:4 aspect ratio looks perfectly fine on my 4K TV, just wondering if the 16:9 aspect ratio would be a better choice.

 

For anyone wanting to connect their Sophia to a TV via HDMI, this little device is very handy:  https://www.amazon.com/gp/product/B009GUNEAI/ 

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56 minutes ago, Colleton said:

For anyone wanting to connect their Sophia to a TV via HDMI, this little device is very handy:  https://www.amazon.com/gp/product/B009GUNEAI/ 

Some TVs accept an analog audio signal for one of the HDMI inputs which allows for Sophia to be connected with a simple DVI to HDMI cable. 

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it makes me wonder, given that Sophia is actively listening to the ANTIC<->GTIA video bus data, and that NTSC mode can be determined, it should be possible to enable artifacting to plot double-wide red/green (blue/black, cyan/red, whatever), pixels when the 7.14MHz dot clock is engaged...

 

-Thom

Edited by tschak909
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Hi,

 

I'm interested in getting one for a 65XE, going for a 16:9 or 16:10 config as it's easier to source such display.

Are they still available and how do we order one and at what price?

 

 

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1 hour ago, AMenard said:

Hi,

 

I'm interested in getting one for a 65XE, going for a 16:9 or 16:10 config as it's easier to source such display.

Are they still available and how do we order one and at what price?

 

 

Send a PM to Simius

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On ‎10‎/‎14‎/‎2019 at 10:27 AM, Colleton said:

I'm thinking of going with the 1536x960 resolution (16:10) as I'll be connecting it to a 4K TV with a 16:10 aspect ration.

 

I thought the same thing and bought mine at 1536x960. I tried it on no less than ten various monitors and televisions I have around the house. Alas, I never found a single one that it would work with. Honestly, it was weeks before I ever saw an image from my Sophia. I started to wonder if it was actually defective. I finally contacted Simius for a firmware update and purchased a USB Blaster and made a cable so I could reprogram my Sophia for 1280x1024. Now it works on every display that I've tried it on. And as long as I have the display setup to display the native aspect ratio of the signal, everything looks great. The image always enlarges to fill as much of the screen as possible, but it doesn't stretch the image in any way. It looks beautiful. If I were to ever order another one, and assuming no major changes to the software, I won't consider anything other that 1280x1024.

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