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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

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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

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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

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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

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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

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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

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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

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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

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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

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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...
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Re: ALPHA MODIFICATIONS

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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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