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Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 11:23
by PhilC
exxos wrote: 25 Sep 2018 22:47
Icky wrote: 25 Sep 2018 22:42
I think you just like to keep me busy with my soldering iron
At least your keeping up, Not sure where the other 15 people have gotten to...
Me? I'd rather sensibly gone to bed :P
Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 12:43
by rubber_jonnie
I'm waaaay behind, on account of other priorities, work, home maintenance etc.
I'm kind of at the stage now thinking I should wait in order to apply all the fixes in one go to see how it turns out!!
I've barely touched an Atari in weeks now :(
Still, winter is coming,which means I should have more Atari time!!
Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 17:47
by PhilC
I can verify that those fixes work on my board too.
And as with Icky's my floppy doesn't want to play either.
Well done guys.
Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 18:16
by PeteW
Forgottenmyname wrote: 26 Sep 2018 17:47
I can verify that those fixes work on my board too.
And as with Icky's my floppy doesn't want to play either.
Well done guys.
Does your display do that periodic blanking like Ickys too or is your picture stable?
I've really enjoyed watching the progress of this from virtually no picture to a nearly functional machine in under 2 weeks :)
If I had a spare motherboard, I'd be well up for being a beta board customer!
Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 18:39
by PhilC
I don't remember seeing it flicker like on the video.
I will try running it again a little later on and see what happens.
I'm wondering if it's a difference in monitor type?
Re: ALPHA MODIFICATIONS
Posted: 26 Sep 2018 23:50
by exxos
FLOPPY FIX
Fixies missing pull ups on the LS06 buffers (never were on any schematic either!)
Solder 10K resistors to either the IC on the bottom of the PCB, or the resistors in a row on top of PCB (which ever is easier).
For example solder a 10K resistor to the highlighted pins on the resistors, then solder the free ends to 5V (tap from pin 14 of LS7406)
1772f.jpg
Re: ALPHA MODIFICATIONS
Posted: 27 Sep 2018 00:09
by Icky
exxos wrote: 26 Sep 2018 23:50
FLOPPY FIX
Fixies missing pull ups on the LS06 buffers (never were on any schematic either!)
Solder 1K resistors to either the IC on the bottom of the PCB, or the resistors in a row on top of PCB (which ever is easier).
For example solder a 1K resistor to the highlighted pins on the resistors, then solder the free ends to 5V (tap from pin 14 of LS7406)
Here is a photo of my quick hack to get this up and running - a cluster of resistors tied to pin 14:
IMG_3115.png
Re: ALPHA MODIFICATIONS
Posted: 27 Sep 2018 10:19
by PhilC
The stripes don't match up :P
Does it need to 1k? I'm running short on those by the looks.
Re: ALPHA MODIFICATIONS
Posted: 27 Sep 2018 10:49
by exxos
Forgottenmyname wrote: 27 Sep 2018 10:19
Does it need to 1k? I'm running short on those by the looks.
No idea. I suggested 10K to Icky.. I guess almost anything would work, even 100K maybe .
Re: ALPHA MODIFICATIONS
Posted: 27 Sep 2018 16:22
by PhilC
If you've kept up, your board should now look a little something like this :)
20180927_162013.jpg
P.s. not done the 16mhz mmu fix as it was optional.