Falcon clock buffer patch V2 progress

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exxos
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Re: Falcon clock buffer patch V2 progress

Post by exxos » Tue Dec 29, 2020 12:44 pm

Steve wrote:
Tue Dec 29, 2020 12:39 pm
Any thought on my sdma clock wire?

No idea what you did ? The buffer board was designed to use the original track, but I guess if you ran a seperate wire it wouldn't cause any issues.. but if you have that resistor on the clock line (47R or whatever) then it needs to be removed.
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Re: Falcon clock buffer patch V2 progress

Post by Steve » Tue Dec 29, 2020 2:15 pm

@exxos

This is what I have Chris -

Screen Shot 2020-12-29 at 14.19.27.png
Screen Shot 2020-12-29 at 14.19.27.png (55.75 KiB) Viewed 1989 times
Screen Shot 2020-12-29 at 14.13.56.png
Screen Shot 2020-12-29 at 14.13.56.png (149.18 KiB) Viewed 1989 times
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Re: Falcon clock buffer patch V2 progress

Post by exxos » Tue Dec 29, 2020 2:25 pm

Not really sure what's going on there, but I would suggest you remove all the stuff and basically take it back to stock as thats how the buffer is intended to be fitted. If you have anything else anywhere, it will likely screw things up. Fitting the buffer is still as before anyway.
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Re: Falcon clock buffer patch V2 progress

Post by Steve » Tue Dec 29, 2020 2:48 pm

exxos wrote:
Tue Dec 29, 2020 2:25 pm
Not really sure what's going on there, but I would suggest you remove all the stuff and basically take it back to stock as thats how the buffer is intended to be fitted. If you have anything else anywhere, it will likely screw things up. Fitting the buffer is still as before anyway.
Well okay.. I mean I am a little confused because the V3 is supposed to mimic the Phantom clock patch, how can it be designed to mimic the Phantom clock patch if you're not sure what is going on there.. that is the phantom clock patch.. Sorry if this sounds rude honestly.
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Re: Falcon clock buffer patch V2 progress

Post by exxos » Tue Dec 29, 2020 2:55 pm

Steve wrote:
Tue Dec 29, 2020 2:48 pm
Well okay.. I mean I am a little confused because the V3 is supposed to mimic the Phantom clock patch, how can it be designed to mimic the Phantom clock patch if you're not sure what is going on there.. that is the phantom clock patch.. Sorry if this sounds rude honestly.
The only difference is the addition of the second buffer chip for the SDMA clock.. I am making the assumption its the total propagation delay though the inverters which is what makes it work. So the current buffer does exactly the same, mimics the delays. In fact IIRC mine actually was a tiny bit slower than the original calculated delay. All those caps / resistors which get bodged on the clock lines I already explained many times. They are also fixed a different way. What I don't get is the images you posted, I'm used to proper schematics.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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Re: Falcon clock buffer patch V2 progress

Post by Rustynutt » Mon Jun 14, 2021 12:29 am

hehe, think Mikro deciphered those :)

Have 4 of your original buffers unused.
Need to get an order in for some V3 (?)
By the time I hack together a Phantom buffer, like having an extra computer board aside :)

With EmuTOS in ROM, am able to boot with a 50 MHz clock.
What I'm finding is the original Nemesis buffer and 150pf cap mod on the DMA doesn't work (well) as with the Nemesis installed.
Audio is fine, DSP-DMA as well, as always, it's SCSI issues.

Tried another builders patch, doesn't do anything (for accelerated bus). They use 0 Ohm resistors in series, possibly allowing for individuals to fine tune, but didn't bother.

Just a follow up note to what I'd seen you mention about your Falcon not booting with a "crowbar" resistor mod on the DMA.
Found pretty much over a 150pf cap on this machine does the same thing. Thought I'd toasted something.

Once an Exxos patch arrives, going to remake the original trace connections, sans the DMA tying in with the FPU clock. That I'll keep separate.

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Re: Falcon clock buffer patch V2 progress

Post by exxos » Mon Jun 14, 2021 12:41 am

Yeah there's to many clock patch variations about. I'm trying to make mine a "one size fits all" so people don't have to bother messing about all the time. There ones in my store are the latest boards.
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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Re: Falcon clock buffer patch V2 progress

Post by Rustynutt » Mon Jun 14, 2021 4:35 am

Order in :)

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