ALPHA MODIFICATIONS

All information relating to the Alpha plus all the WIP threads etc.
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Icky
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Re: ALPHA MODIFICATIONS

Post by Icky » Tue Sep 25, 2018 8:42 pm

exxos wrote:
Tue Sep 25, 2018 2:21 pm
RAM RW FIX

Fixes wrong RW line connected to RAM.
Fix in place

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Re: ALPHA MODIFICATIONS

Post by exxos » Tue Sep 25, 2018 9:08 pm

1772 IRQ TYPO FIX

Pin 28 of the 1772 had a typo and wasn't connected to the MFP...

Bodge wire as shown below...

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Actually this explains some confusion of the missing pull up on the MFP as it should be going to pin 2 of that pack, that lines doesn't actually have a pull up on the ST diagram.
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Re: ALPHA MODIFICATIONS

Post by exxos » Tue Sep 25, 2018 10:33 pm

KEYBOARD RESISTOR FIX

Fixes missing pull down (first pull down missing! so yay! :lol: )


Solder a 10K resistor between the 2 highlighted pins..

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Then have a shot of whiskey...
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Re: ALPHA MODIFICATIONS

Post by Icky » Tue Sep 25, 2018 10:39 pm

exxos wrote:
Tue Sep 25, 2018 10:33 pm
KEYBOARD RESISTOR FIX
Does that mean U52 has the same problem - judging by the schematic and your history with pull-ups :)

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Re: ALPHA MODIFICATIONS

Post by exxos » Tue Sep 25, 2018 10:40 pm

Icky wrote:
Tue Sep 25, 2018 10:39 pm
Does that mean U52 has the same problem - judging by the schematic and your history with pull-ups :)
Oddly I added that one :)
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Re: ALPHA MODIFICATIONS

Post by Icky » Tue Sep 25, 2018 10:42 pm

exxos wrote:
Tue Sep 25, 2018 10:40 pm
Icky wrote:
Tue Sep 25, 2018 10:39 pm
Does that mean U52 has the same problem - judging by the schematic and your history with pull-ups :)
Oddly I added that one :)
I think you just like to keep me busy with my soldering iron

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Re: ALPHA MODIFICATIONS

Post by exxos » Tue Sep 25, 2018 10:47 pm

Icky wrote:
Tue Sep 25, 2018 10:42 pm
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...
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Re: ALPHA MODIFICATIONS

Post by Icky » Tue Sep 25, 2018 10:53 pm

exxos wrote:
Tue Sep 25, 2018 10:47 pm
Icky wrote:
Tue Sep 25, 2018 10:42 pm
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...
I think they are watching the fun Forgottenmyname, you and I are having before they embark on this adventure :)

Unfortunately that fix made no change - keyboard still not working or reporting in the diagnostic cart

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Re: ALPHA MODIFICATIONS

Post by exxos » Tue Sep 25, 2018 10:54 pm

Icky wrote:
Tue Sep 25, 2018 10:53 pm
Unfortunately that fix made no change - keyboard still not working or reporting in the diagnostic cart
ah crap.. will have a final snoop then calling it a day.. out all day tomorrow so have to pickup Thursday...
https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.

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Re: ALPHA MODIFICATIONS

Post by Icky » Tue Sep 25, 2018 10:55 pm

exxos wrote:
Tue Sep 25, 2018 10:54 pm
Icky wrote:
Tue Sep 25, 2018 10:53 pm
Unfortunately that fix made no change - keyboard still not working or reporting in the diagnostic cart
ah crap.. will have a final snoop then calling it a day.. out all day tomorrow so have to pickup Thursday...
No - not crap. Its fixed the sound. We have sound.

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