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Re: Video driver thoughts

Posted: 27 Nov 2018 22:06
by PhilC
Sorry guys, I misled you earlier, I forgot I was using the ube switch and it was mono mode that was ok.

Booting into low or med rez I get a black screen.

Can't get to desktop tonight. Looks like I at least need a new shifter socket and probably a glue or rom socket as well, so won't be much more help until I've got all that done.

Which chips are we safe to solder in now? 68901 6850,?

Re: Video driver thoughts

Posted: 27 Nov 2018 22:12
by exxos
Forgottenmyname wrote: 27 Nov 2018 22:06 Which chips are we safe to solder in now? 68901 6850,?
Yeah, probably YM chip as well.

Re: Video driver thoughts

Posted: 27 Nov 2018 22:16
by PhilC
Ok, think I will solder those in as well as I have spares of each for the mongrel board etc when we get that far.

Re: Video driver thoughts

Posted: 27 Nov 2018 22:17
by exxos
Icky wrote: 27 Nov 2018 21:44 75R just makes it even more darker and the border is still black
I will have to try and find some time this week to build up mine and see what happens... It kinda just sounds like its got a floating pin somewhere, but out of ideas otherwise :(

Re: Video driver thoughts

Posted: 28 Nov 2018 07:49
by Icky
exxos wrote: 27 Nov 2018 22:17
Icky wrote: 27 Nov 2018 21:44 75R just makes it even more darker and the border is still black
I will have to try and find some time this week to build up mine and see what happens... It kinda just sounds like its got a floating pin somewhere, but out of ideas otherwise :(
So in looking at the schematics etc it seems that a lot of pins are not connected on the Falcon as mentioned before. I personally don’t have a Falcon but was wondering if this was truely the case. Are these pins floating or connected to ground in the real thing. Pins 13,14,27 & 28.

Re: Video driver thoughts

Posted: 28 Nov 2018 09:39
by exxos
I can double check but will have to be tomorrow as just on my way out..

Though I was following the datasheet mostly...

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Re: Video driver thoughts

Posted: 28 Nov 2018 16:45
by exxos
What you could do, is wire the board up on breadboard, put switches and pull ups on the red channel, then you can step through each binary number and measure the voltage steps on the outputs..

Re: Video driver thoughts

Posted: 28 Nov 2018 17:01
by sandord
I got my PCB in the mail yesterday. One quick question: is it wise to try to solder the video DAC chip without soldering paste, just using a regular soldering station?

Re: Video driver thoughts

Posted: 28 Nov 2018 17:15
by exxos
sandord wrote: 28 Nov 2018 17:01 I got my PCB in the mail yesterday. One quick question: is it wise to try to solder the video DAC chip without soldering paste, just using a regular soldering station?
Well, you should do which you find best yourself... I would probably suggest coating the pads with solder first, keeping it to a minimum, then flux the pads, then solder the IC.

Re: Video driver thoughts

Posted: 28 Nov 2018 17:16
by sandord
exxos wrote: 28 Nov 2018 17:15 Well, you should do which you find best yourself... I would probably suggest coating the pads with solder first, keeping it to a minimum, then flux the pads, then solder the IC.
Thanks, that's really helpful. The thing is, I never soldered a SMT chip before :D