Icky - Progress

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Icky
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Re: Icky - Progress

Post by Icky »

New WD1772 arrived in the post today - Thanks Exxos

Have been trying differing combinations and this is the one that works.

Looks like I have a NASTY DMA, NOT SO BAD DMA, GOOD 1772 and BAD 1772.

DMA-1772.png
DMA-1772.png (869.78 KiB) Viewed 4203 times

You may of noticed my STF has been mounted on a perspex square makes it easier to have every thing stable to move around instead of juggling wires and things on top of each other.

IMG_3164.png
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PhilC
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Re: Icky - Progress

Post by PhilC »

So does the hd and fd play nice together now?
If it ain't broke, test it to Destruction.
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Re: Icky - Progress

Post by Icky »

Forgottenmyname wrote: Sat Oct 13, 2018 11:13 am So does the hd and fd play nice together now?
Indeed - They work together we have success.

See desktop pic of A and C drive.
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Re: Icky - Progress

Post by PhilC »

Sorry, looking on phone at the mo.

Do you think it's worth listing good and bad combinations?
If it ain't broke, test it to Destruction.
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Re: Icky - Progress

Post by Icky »

Forgottenmyname wrote: Sat Oct 13, 2018 11:27 am Sorry, looking on phone at the mo.

Do you think it's worth listing good and bad combinations?
Sounds like a good idea.

I need to try the NASTY DMA in an original machine to see if it works there or not.

Will have to wait till later have DIY to tackle today. :)
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Re: Icky - Progress

Post by exxos »

Icky wrote: Sat Oct 13, 2018 11:30 am I need to try the NASTY DMA in an original machine to see if it works there or not.
That's the key question currently


lol @ no so nasty dma :lol:
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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Re: Icky - Progress

Post by Icky »

So here concludes my observations of all the various permutations of the DMA and WD1772 in the STF Remake:

DMAWD1772FLOPPYHDDObservations
NASTYBADSeen when HDD not connectedNot seenFloppy only seen when HDD not connected otherwise no drives on desktop
NOT SO BADBADNot seenSeen
NOT SO BADGOODSeenSeenWorking combination
NASTYGOODSeenNot seenFloppy seen when HDD connected or not

Back to DIY - will check NASTY DMA in original ST later tonight.
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Re: Icky - Progress

Post by exxos »

:thumbup:

If your running fine, can you copy so files from floppy to hard drive and check HDCS and FDCS on the DMA... Both on scope at same time... So when you see FDCS go low and the high, there will be some delay then you should see HDCS going low.... Its the delay between the 2 which is of interest...
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viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
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Re: Icky - Progress

Post by Icky »

exxos wrote: Sat Oct 13, 2018 3:12 pm :thumbup:

If your running fine, can you copy so files from floppy to hard drive and check HDCS and FDCS on the DMA... Both on scope at same time... So when you see FDCS go low and the high, there will be some delay then you should see HDCS going low.... Its the delay between the 2 which is of interest...
Thanks Exxos. I'll take a look once I have tested the NASTY DMA in my original ST to confirm that it truly is NASTY :)
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Re: Icky - Progress

Post by exxos »

I half wonder if those ste buffers , while they will cure the 1772 bus conflict, if they are also a contributing issue as to why the ste suffers with write issues on the DMA port... Just thinking out load here, but can't help but feel delaying the bus to the DMA by up to 1x 8mhz clock cycle isn't really a good thing to do.

As though before, I think a buffer between the 1772 and DMA would be a better idea, and buffers would isolate the 1772 bus fast, but it wouldn't add delays to the DMA port, which think is a good thing.

There is still the idea to add buffers on the DMA port, but I don't think they are really needed...

I also half wonder if that 1772 conflict is part of some screwy things I saw on the DMA bus ages ago.. As the 001 DMA seemed to act like a open collector output, but it seemed to magic up delays when the bus was loaded more, which suggest a open collector type output, but even so, I never really figured out why the 001 had this odd behaviour. But maybe if the 1772 bus was conflicting with the DMA, that could be part of the confusion as to why the 001 was acting oddly, when the -38 didn't.

I didn't look into it much at the time .. But maybe the 001 checks for all logic hi on the bus before it actually outputs data to the bus. That's the only way I can describe it. It would kinda make sense and tally with the odd results I found. Though with the ste buffers, it shouldn't need that odd 001 "logic". On that basis , the stfm would be the main useage of the 001 not the ste... I don't think I ever saw any 001 DMA in a stfm.. Only later ste....
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
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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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