Q40 and Q60 video controller for flatscreen monitors

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Derek_Stewart
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Derek_Stewart »

Hi,

I was not being serious about the saw.

I did realise the implementation of the suggestion.

So this potential upgrade does change the design of the Q60.

I would be interested in seeing more specific details.

I have a little work to do at present, but I think I may make some Q60 boards, the main reason, is that, I do not have a working Q60...


Regards,

Derek
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Peter
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Peter »

Szk wrote:Pictures from Mr. Mark Smith in this FB thread where he describe his attempt to replace an old CPLD on a TC2068.
I hope it can help... ;)
Thanks, but not so much. Your pictures showed a PLCC IC replacement soldered to SMD pads on PCB. I have done that before, but it is not suitable for the Q60, which has sockets.
(By the way, if sockets were removed, the PCB footprint is not SMT but THT.) Dave had already posted a picture of a castellated board example which would fit.

Don't let this hold you back from posting hardware ideas.


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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Nasta »

From what I can gather, Peter is limited to a 60MHz dot clock, which translates roughly into a 1024x768 pixel frame at 50Hz - this is the same on Aurora.
That all being said, is it possible to center the 512 visible lines within the 768 line frame on the Q60? Some monitors are really finicky and will sometimes completely disregard the position of the synch signals in favor of where they think they detect active pixels...
Regarding digital out, it should be possible to provide that by making a riser card that connects to the CPLD socket pins and holds the CPLD (perhaps on a surface mounted socket) and a DVI coder chip. Alternatively, the digital signals are available at the resistor networks that make up the RGB DAC, however one has to also get a dot clock from somewhere.
Regarding pseudo-fullHD, this would be ideal. It's become almost impossible to find anything other than 16:9 aspect ratio monitors and the Qx0 2:1 resolution may well be far better suited for them.
Also, an observation from another time trying to get LCD monitors to work at non-standard 1024x768 timing - most, even the stunted intelligence ones, seem to have far worse problems with horizontal timing, vs. vertical timing. Usually they are far more tolerant to using less vertical retrace to get a higher refresh rate. That being said, an LCD screen is a form of dynamic RAM, and one with a fairly high data retention time (this is because on an active matrix the pixels are turned on and also turned off - if just turned on, they do fade eventually but it takes a _lot_ more time than when actively driven either on or off) so insisting on a higher frame rate is questionable. It also occurs to me that the 'secretly' supported frame rates are there for compatibility with older HDTV standards, which are in turn based on yet older standards.


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Peter
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Peter »

Nasta wrote:That all being said, is it possible to center the 512 visible lines within the 768 line frame on the Q60?
When I last tried that, I did not find a way. The responsible chip is extremely full, which makes even simple changes difficult.
Nasta wrote:Regarding digital out, it should be possible to provide that by making a riser card that connects to the CPLD socket pins and holds the CPLD (perhaps on a surface mounted socket) and a DVI coder chip.
That is possible in principle. However, if one wants to change more than the "color generator", there are two CPLDs and sockets involved. Connecting to these sockets tends to make such card a project consisting of 2 or 3 PCBs. 1 or 2 castellated small PCBs that plug into the socket(s). Plus one main PCB. That card would still be limited by the Q60 VRAM.

Peter


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Chr$
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Chr$ »

Peter or Derek (or anyone able to program one),

Could you supply this updated chip to me? I don't have a CRT VGA monitor and I don't mind some blackness - better than a line or 2 of missing text.


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Derek_Stewart
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Derek_Stewart »

Hi Chr$,

I missed this, I will get this done over Christmas, I have to make a programming adapter to ptogramme the chip.


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Derek
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Peter
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Peter »

Chr$ wrote:Could you supply this updated chip to me?
I can program them, but my stock of chips has become small. Would it be okay to re-program the chip you have?
Chr$ wrote:I don't have a CRT VGA monitor and I don't mind some blackness - better than a line or 2 of missing text.
Unfortunately not just a few lines, it's a third of the screen!

If you want to spend some money, there is a better solution, according to a user from France: http://qdos.free.fr/monitors.html


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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Chr$ »

Peter wrote: I can program them, but my stock of chips has become small. Would it be okay to re-program the chip you have?
This'll do it, right?

https://www.ebay.de/itm/LATTICE-ISPLSI1 ... 3533762297

If so, I don't mind buying it and getting it sent to you. I have to keep the original in its original state! ;)

It might be quicker and easier within Germany while Derek is sorting out his programmer (and of course, with potential customs and nonsense for UK goods in a few days).

Edit: or this one, as I'm not sure if the E suffix to the 1016 above, is significant:

https://www.ebay.de/itm/1-Stuck-ISPLSI1 ... 2193767941


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Peter
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Peter »

No.
Yes.


Derek_Stewart
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Re: Q40 and Q60 video controller for flatscreen monitors

Post by Derek_Stewart »

Peter wrote:
Chr$ wrote:Could you supply this updated chip to me?
I can program them, but my stock of chips has become small. Would it be okay to re-program the chip you have?
Chr$ wrote:I don't have a CRT VGA monitor and I don't mind some blackness - better than a line or 2 of missing text.
Unfortunately not just a few lines, it's a third of the screen!

If you want to spend some money, there is a better solution, according to a user from France: http://qdos.free.fr/monitors.html
Hi,

The OSSC is really expensive, but since it is open source another idea would to try and make them at a less expensive price.


Regards,

Derek
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