CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

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Paulo P
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CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Paulo P »

Here are the pictures of my Atari STe motherboard.

IMG_20180118_130655.jpg
IMG_20180118_130655.jpg (4.04 MiB) Viewed 11473 times
What is this cable for? Does anybody know?
What is this cable for? Does anybody know?
IMG_20180118_130749.jpg (4.06 MiB) Viewed 11473 times
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rubber_jonnie
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by rubber_jonnie »

I've seen that wire a couple of times now, I strongly suspect it is a factory 'bodge'.
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exxos
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by exxos »

rubber_jonnie wrote: Thu Jan 25, 2018 11:07 am I've seen that wire a couple of time now, I strongly suspect it is a factory 'bodge'.
I seen it as well. If someone looked up what pin it was on the IC, then see whats going on better. Think they just added a pull up to a pin as the wire goes to the SIL array.
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Maeke
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Maeke »

I have the same wire on my ste.
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by rubber_jonnie »

Unless I'm counting wrong, that wire is going to pin 1 of the Shifter.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Paulo P
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Paulo P »

I read somewhere few days ago, that this is for some voltage stability reason. I don't know if this is right or not.
Paulo P
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Paulo P »

And here are the pictures after recap and some other little improvements (for example, LMC mixer audio fix). More here:

- https://www.exxosforum.co.uk/atari/last/ ... /index.htm ("STE LMC MIXER AUDIO FIX")
- http://forum.8bitchip.info/hardware-16/ ... er'-error/ ("Fixing STE microwire "mixer" error")

Motherboard_after_recap-01.jpg
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Motherboard_after_recap-02.jpg
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Paulo P
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Paulo P »

I've noticed that one chip on the left of the processor is missing on my board compared to other STe mainboards. Does anybody know, what is it good for?
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Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by exxos »

Paulo P wrote: Fri Apr 20, 2018 8:58 am I've noticed that one chip on the left of the processor is missing on my board compared to other STe mainboards. Does anybody know, what is it good for?
Its the blitter... Its integrated in the large SMT chip to the left on later machines.
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Paulo P
Posts: 21
Joined: Tue Jan 16, 2018 1:22 pm

Re: CA4003290 Rev (C300779-001 Rev B 2) 1989 - Atari STe

Post by Paulo P »

exxos wrote: Fri Apr 20, 2018 9:02 am
Paulo P wrote: Fri Apr 20, 2018 8:58 am I've noticed that one chip on the left of the processor is missing on my board compared to other STe mainboards. Does anybody know, what is it good for?
Its the blitter... Its integrated in the large SMT chip to the left on later machines.
Thanks very much for your answer. I had a little bad feeling that my board has missing something. :)
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