Falcon Fun.

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stephen_usher
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Falcon Fun.

Post by stephen_usher »

The Falcon is now on the bench!

I picked up the stuff from work thins morning and the first thing to test was to see if either or any of the two 72 pin 16MB SIMMs would work in the machine.

Well, the first one didn't. Just a dark screen with some coloured lines down the right hand side of the screen with the diag cartridge plugged in.

The second one needed some of the contacts cleaning with a fibre pen before inserting but once that was done... all good. I'm now running YAART-TT on the machine and it's on pass 2 now. I'll leave it running until after lunch, after which I'll start dismantling the machine more ready for its NVRAM-ectomy.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Re: Falcon Fun.

Post by stephen_usher »

With the old NVRAM safely removed I fitted the Exxos replacement. However, instead of installing the small coin cell on top (which I don't have) I soldered wires and a CR2032 holder, which I can install in a location where it can be easily changed without dismantling the whole system. Hot glue to the rescue!

IMG_2759.jpg
IMG_2759.jpg (436.66 KiB) Viewed 1106 times

Seeing as there are currently no (CPU) clock issues I'll leave the clock patch for another time I think. I realise that if/when chips' tolerances drift over time I may have to go back and revisit this as the timings are on the edge.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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exxos
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Re: Falcon Fun.

Post by exxos »

Could you scope the clocks on both sides of the resistors where the clock patch wires normally go ? On x10 of course.

I'm actually writing a article about the clock patch stuff.. But don't have a stock machine anymore..
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.
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stephen_usher
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Re: Falcon Fun.

Post by stephen_usher »

OK, I'll see what I can do later, when the Sun goes down and I can take pictures of the 'scope screen.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Re: Falcon Fun.

Post by stephen_usher »

Well, that's fascinating. The mounting holes for the original 2.5" hard drive don't correspond with later, standard holes. I've had to use double-sided foam tape to stick the new drive into the machine.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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stephen_usher
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Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
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Re: Falcon Fun.

Post by stephen_usher »

exxos wrote: Sun Aug 07, 2022 3:35 pm Could you scope the clocks on both sides of the resistors where the clock patch wires normally go ? On x10 of course.

I'm actually writing a article about the clock patch stuff.. But don't have a stock machine anymore..
Just to be clear. This is two probes, one each side of each resistor in turn? How about one probe per clock line to determine skew?

Just checked with one probe. They all look nice. 5.12V on one side and 5.04V on the other. All nice and clean and almost a perfect sine wave.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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exxos
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Re: Falcon Fun.

Post by exxos »

stephen_usher wrote: Sun Aug 07, 2022 5:07 pm Just to be clear. This is two probes, one each side of each resistor in turn? How about one probe per clock line to determine skew?

Just checked with one probe. They all look nice. 5.12V on one side and 5.04V on the other. All nice and clean and almost a perfect sine wave.
One side of the resistors is all connected together. The other sides are clock outs. You measure each point to gnd.

Are you testing with x10 probe ?
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.
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stephen_usher
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Re: Falcon Fun.

Post by stephen_usher »

Please forgive the pictures. Holding the phone in one hand whilst probing with the other.

R216

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IMG_2760.jpg (316.5 KiB) Viewed 1051 times

R221

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IMG_2761.jpg (309.2 KiB) Viewed 1051 times

R222

IMG_2762.jpg
IMG_2762.jpg (318.01 KiB) Viewed 1051 times
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
User avatar
exxos
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Posts: 23488
Joined: Wed Aug 16, 2017 11:19 pm
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Re: Falcon Fun.

Post by exxos »

Thanks.. That's confusing now.. As if the clocks are that clean, there would be no need for a clock patch. I've seen all sorts of ringing..always. I'll have to refit the resistors on mine and see if I get the same results.
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.
Steve
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Joined: Fri Sep 15, 2017 11:49 am

Re: Falcon Fun.

Post by Steve »

I've always heard rumours of Falcons that don't need clock patches, @stephen_usher please upload high Res motherboard photos at some point :)
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