exxos's Atari, Amiga & retro forum

Didn't know the MEGA ST had a internal port.. Will look into it...

OK so literally a internal port then... I've no idea what addons are for it, but makes sense to add it.

I was also half plotting of adding a full DMA header row to access all the DMA pins.. thought was to hi-jack the databus and bypass the DMA chip itself.. but not looking in that direction really now.. with FPGA DMA also available , we can actually push faster speed once we have a faster MMU/RAM access speeds.

I guess for sh*ts and giggles, if someone is bored enough, clock the DMA at 16mhz and see if it still behaves

exxos wrote: ↑Sun Oct 21, 2018 10:40 pm I guess for sh*ts and giggles, if someone is bored enough, clock the DMA at 16mhz and see if it still behaves

Now that will depend on the DMA chip you have - BAD DMA or a NASTY DMA

Icky wrote: ↑Sun Oct 21, 2018 10:46 pm Now that will depend on the DMA chip you have - BAD DMA or a NASTY DMA

IMP - pure evil DMA...

I guess its possible the drive could run a bit faster.. but its bottlenecked by ST-RAM anyway... I mean peters special drive can run twice as fast as ultrasatan with special hardware and software, so the DMA transfer is capable of double speeds.. So 16MHz DMA could work.. if Ultrasatan can keep up

exxos wrote: ↑Sun Oct 21, 2018 10:49 pm

Icky wrote: ↑Sun Oct 21, 2018 10:46 pm Now that will depend on the DMA chip you have - BAD DMA or a NASTY DMA

IMP - pure evil DMA...

I guess its possible the drive could run a bit faster.. but its bottlenecked by ST-RAM anyway... I mean peters special drive can run twice as fast as ultrasatan with special hardware and software, so the DMA transfer is capable of double speeds.. So 16MHz DMA could work.. if Ultrasatan can keep up

I'll give it a go tomorrow night - just been checking at what speed Gigafile can run at.

Its supposed have max transfer rates at 1800Kbps read and 1200Kbps write and an using it with an original Atari ST is supposed to be 1200Kbps read and 1000Kbps write.

So I should be able to detect improvement if it works.

Icky wrote: ↑Sun Oct 21, 2018 11:53 pm I'll give it a go tomorrow night - just been checking at what speed Gigafile can run at.

Its supposed have max transfer rates at 1800Kbps read and 1200Kbps write and an using it with an original Atari ST is supposed to be 1200Kbps read and 1000Kbps write.

So I should be able to detect improvement if it works.

That be super cool if it does clock faster

exxos wrote: ↑Sun Oct 21, 2018 12:51 am Maybe lotherak could be convinced to do a proper internal ultrasatan? To him it would only be a PCB change and would only need the pcb for internal mounting.

He already has an internal UltraSatan:

https://lotharek.pl/productdetail.php?id=47

IngoQ wrote: ↑Mon Oct 22, 2018 12:31 pm He already has an internal UltraSatan:

Even better! That can't fit vertically in the DMA header though surely ?

EDIT:
Never mind.

https://lotharek.pl/productdetail.php?id=50

Think I will have to get one of those and see where it could be located on the STF board with a suitable adapter.

I have just ordered a internal and external version with the MEGA ST adapter kit..

Early xmas prezzies for me

Once I get them, I can start plotting where the best location would be to mount the connector and fixing holes etc..

It's the internal one that I have. Did work great until the sd card died.