DMA port "update" ideas..

[Icky]

Good morning Icky. If its questionable I totally agree however I haven't had any issues. Board real-estate is precious and we shouldn't add fixes that are just in case. When all the boards are built and running we will have a better sample of operation reliably. You said yours is running reliably. What did you have to do to achieve the reliable operation, I know you were using a various different chips?

Hi PaulJ - To clarify my statement of the board being solid. It has been on solidly for several days and using only the floppy to run programs, looping GemBench and play games etc.

I am not using HDD at the moment as my Megafile bit the dust this morning (not related to STF) and only having one good Gigafile at the moment I am a bit wary of using it with the STF.

From the perspective of chips I am currently running with a new WD1772 from Exxos and a DMA -38 from my 520STM. I have no other spare DMA chip or WD1772 chip a part from my NASTY DMA labeled one and what I also believe to be a shot WD1772.

I agree we will have a better sample set as we gather more of these boards together. Also agree real-estate is precious.

The fixes are in part "just in case" but we know of issues now and they should be fixed. Let's do it right and not start down the path of the STE buggy DMA chaos ...

I have a imp chip set, that goes apesh*t on the ste, so be interesting if it works on my stf. The floppy does so far.

I think as Exxos has said we have realised this flaw in the original design and we can fix.

[PaulJ]

Yes, if it's a solid issue we should fix.

[exxos]

I had a issue on my STE where a hard drive would cause the floppy drive to stop working.. thats even with the buffers on the STE.. thats why I want to add the 1772 buffers as well , I think it will solve that type of issue.

[exxos]

I am not using HDD at the moment as my Megafile bit the dust this morning (not related to STF) and only having one good Gigafile at the moment I am a bit wary of using it with the STF.

It probably would be ok if your not copying files to or from the hard drive to floppy...

I need to get a new gigafile at some point as well..

Was half wondering if we should use the gigafile connector instead of the DB19.. GF would plug right into the STF then. Likely we can route power to the port as well.

[Icky]

I am not using HDD at the moment as my Megafile bit the dust this morning (not related to STF) and only having one good Gigafile at the moment I am a bit wary of using it with the STF.

It probably would be ok if your not copying files to or from the hard drive to floppy...

I need to get a new gigafile at some point as well..

Was half wondering if we should use the gigafile connector instead of the DB19.. GF would plug right into the STF then. Likely we can route power to the port as well.

Not a bad idea. That way there would be easy cables to use with Gigafile and Ultrasatan including power them. Also solves the lack of 19pin D-Subs

[kodak80]

It probably would be ok if your not copying files to or from the hard drive to floppy...

I need to get a new gigafile at some point as well..

Was half wondering if we should use the gigafile connector instead of the DB19.. GF would plug right into the STF then. Likely we can route power to the port as well.

Not a bad idea. That way there would be easy cables to use with Gigafile and Ultrasatan including power them. Also solves the lack of 19pin D-Subs

Would be good to have both the current 19 pin D-Sub and a 20 IDC pin Gigafile type male header for internally connecting SatanDisk/CommosEx/Gigafile with a 2 pin header for power. We would need a 12v and 5v option for powering the various devices. Would this work if both an external device and internal device is connected?

This is the cable pin out I follwed when manually connecting my SatanDisk as I have header pins on my first board:

dma_cable.png (32.19 KiB) Viewed 4886 times

[Icky]

Not a bad idea. That way there would be easy cables to use with Gigafile and Ultrasatan including power them. Also solves the lack of 19pin D-Subs

Would be good to have both the current 19 pin D-Sub and a 20 IDC pin Gigafile type male header for internally connecting SatanDisk/CommosEx/Gigafile with a 2 pin header for power. We would need a 12v and 5v option for powering the various devices. Would this work if both an external device and internal device is connected?

This is the cable pin out I follwed when manually connecting my SatanDisk as I have header pins on my first board:
dma_cable.png

The MegaSTE has an internal ACSI header and there are boards to aid fixing to Gigafile and UltraSatan to this header. I know with the Gigafile one it also provides the power as well from the header.

I also thought that we might need additional power connectors (CN2) to allow us to connect more than one internal add-ons to the power source - mentioned in remake suggestions - https://www.exxosforum.co.uk/forum/viewt ... =50#p11929

Here is a pic of Gigafile connected to the header with the small MegaSTE ACSI to Gigafile board:

IMG_3171.png (1.5 MiB) Viewed 4883 times

However I think what Exxos was getting at (correct me Exxos if I am wrong here) is to change the ACSI 19 pin D-SUB with the HD D-SUB. That way it would work with Gigafile, provide power and a cable could be built to connect to UltraSatan or original ACSI.

5054-VGA-Buchse-gewinkelt-Bolzen.jpg (20.73 KiB) Viewed 4883 times

[exxos]

However I think what Exxos was getting at (correct me Exxos if I am wrong here) is to change the ACSI 19 pin D-SUB with the HD D-SUB. That way it would work with Gigafile, provide power and a cable could be built to connect to UltraSatan

Yep.

I plan to add a DMA internal header anyway.. People may not be aware that myself and peter was working on a fast cf drive a while back, but so many DMA bugs.. We gave up.. But the project isn't dead, with a proper motherboard now we will at some point work on the project again. Its twice as fast as ultrasatan!

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.

[PaulJ]

That would be a great idea!!

[troed]

I've used the Mega ST internal ACSI format (added it to my main STE) to connect an internal Unicorn. I haven't really looked into the differences between the Mega STE internal ACSI and the Mega ST one, but quite a few existing stuff are compatible with the Mega ST.