exxos's DFB1 trials

[exxos]

So this is what page 2 looks like

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[dml]

Yep, and don't expect it to get any less weird with the next one.

Does the FPU actually heat up running that or is it quite happy?

[exxos]

Yep, and don't expect it to get any less weird with the next one.

I stopped it at this point because I went for tea...

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Does the FPU actually heat up running that or is it quite happy?

Will get back on that one. I think it just goes slightly warm.

I just swapped out the oscillator for the one which is 40MHz.. well its 39.80MHz.. so I *think* that may work...

And off it goes... Definitely a LOT faster than 25MHz

I think it would still take forever to draw a screen even with with a 400MHz FPU Though we could run a bank of FPU's, that be cool BadMooD with dual FPU..

[exxos]

It's been running for ages. I even tried a second FPU and it also seems to run fine at 40MHz.

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[dml]

I'd call that config stable, whatever it is for today

[exxos]

I'd call that config stable, whatever it is for today

Yeah I've got an antenna linked to the FPU clock which is positioned at a particular angle of the PSU core, so that when the inverse flux of the core is picked up, it smooths out the noise in the clock helping keep it stable.

[Badwolf]

My multimeter shows about 4.89V.

On the scope.. 10ms /timebase

Multimeter shows 5.014/5.

Scope shot to come.

FWIW, Mandelbox took 50:25 minutes to render this at 50/25MHz.

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Got myself a dedicated oscillator matched to my FPU too.

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Also, BTW, hooked this up as a quick test late last night. It's Orion_'s SD card hack. Six Dupont wires and a 5V SD module. Writing is a bit hit-and-miss, but 700kbps reading with DFB1 and will let you copy a from PC-formatted (FAT16, mind) partitions faster than floppy access. I'm thinking about your Doom transfer

https://www.atari-forum.com/viewtopic.p ... 83#p434183

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With EmuTOS or MiNT it'll speak to larger partition sizes too. Handy hack.

BW


PS: and yes, I'm already thinking about if I can attach it to DFB1 with a suitable software hack

[exxos]

I need to sort out my CF card then file transfer is easy. But the PC seems to trash the card and then isn't read on the falcon. Maybe some software keeps deciding to "fix" the card.

I've boxed up the DFB1 with a couple of 100pf caps, 50mhz OSC, A spar tested 40mhz FPU and a non-exciting mystery item.

[Badwolf]

@dml, if I know anything about fractals, I suspect each render has a completely different draw time on account of it varying what is being shown, but I do wonder if I made a mistake earlier and quoted a 50/16 minutes-per-frame figure of 50.

I've removed R18 and added my 30MHz FPU oscillator and have left this running for about two and a half hours. Currently it's averaging about 32 minutes per frame. Pretty decent improvement and in line with a 30MHz to 16MHz ratio.

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Now I really want to get this board back into 'stock' configuration to let me swap it with Exxos, but I was keen to try this out.

BW

[Badwolf]

I need to sort out my CF card then file transfer is easy. But the PC seems to trash the card and then isn't read on the falcon. Maybe some software keeps deciding to "fix" the card.

Atari IDE is wonky, so I'm impressed you have anything that works like that (short of EmuTOS), TBH.

I've boxed up the DFB1 with a couple of 100pf caps, 50mhz OSC, A spar tested 40mhz FPU and a non-exciting mystery item.

Cool. I'll get this one back into stock condition and send it back in the same box. Swapsies.

BW