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: 25 Sep 2018 14:21 RAM RW FIX

Fixes wrong RW line connected to RAM.
Fix in place

IMG_3104.png
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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...

1772.jpg


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..

aciaf1.jpg

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

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exxos wrote: 25 Sep 2018 22:33 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: 25 Sep 2018 22:39 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: 25 Sep 2018 22:40
Icky wrote: 25 Sep 2018 22:39 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: 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...
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Re: ALPHA MODIFICATIONS

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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...
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: 25 Sep 2018 22:53 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: 25 Sep 2018 22:54
Icky wrote: 25 Sep 2018 22:53 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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