Iyonix DVI Advice

Can anybody give me any advice on the state of play with regard to the RISC OS and DVI output? I’ve read many posts/articles (mostly quite old) but I haven’t found a definitive answer.

I have a Nvidia FX5200 (DVI & TV out) card fitted to my Iyonix and it can display to an analog monitor through a DVI→VGA adapter. It’s not outputting digital signals though, as it won’t display directly through the DVI output to a digital monitor or through a DVI KVM.

Is is true to say then that RISC OS does not support digital output? If so, is it ever likely?

Apologies if this has been stated before here.

Cheers,
Mike.

Is it true to say then that RISC OS does not support digital output?

Yes.

If so, is it ever likely?

No.

The big problem we have is that there’s no public documentation for the graphics cards, so working out what’s needed to enable the DVI output would be pretty difficult.

Thank you for the info.

The nouveau Linux driver supports dual-head with DVI on the NV34-series (to which the 5200 belongs). I haven’t waded through the code but it does appear to do sufficient register poking that it might be feasible to work out what it’s doing in that specific case.

John Ballance did tell me a few years ago, that it could be done if anyone ever managed to find the necessary registry settings!

Searching “http://cgit.freedesktop.org/nouveau/linux-2.6/tree/drivers/gpu/drm/nouveau/nouveau_connector.c” for ‘detect’ reveals some interesting info!

This might be a good bounty. (Although I’m currently not sure what advantages the Iyonix has over a Pi.)

I’m currently not sure what advantages the Iyonix has over a Pi.

Floppy disc drive?!

I’m currently not sure what advantages the Iyonix has over a Pi.

Floppy disc drive?!

Hmmm, Being a long time user I have equipment through from the BBC B, with the RPC actually doing the main job of mail (never got round to migrating the mail to the Iyonix) and I now have beagle-xm and Pi boards.

All that and the last time I used a floppy drive was on the wifes PC to read the content of a floppy disc with a social club membership list that hadn’t been passed over on a memory stick (in excel – quickly converted to CSV for portability)
Time to look at hanging a USB floppy off a NAS and trim all the machines down methinks.

Well the Iyonix has UDMA disc access and also Serial ports.

A USB to Serial port driver would take that away but if using MessengerPro in server mode then disc access may be an issue.

Then again price/functionality ratio is one very big factor in favour of the Pi at the moment.

If DVI could be added without diverting to much development away from the Pi/Beagle/Panda boards then why not do it.

Then again RISC OS on a OMAP5 based board with USB3/Sata2 controllers on will sort disc speeds out..we all can have dreams.

Then again RISC OS on a OMAP5 based board with USB3/Sata2 controllers on will sort disc speeds out..we all can have dreams.

Ah, yes.
Maybe it will be mITX form factor, like the KTT30 board – lots of nice peripheral port space in that.
No indications from TI on an OMAP5 release at present.AFAIK

Well the Iyonix has UDMA disc access and also Serial ports.

There seems some question of whether the Pi is limited to 2048 screen width,the Iyonix can go higher, as I understand but would this be true for a DVI output?

Is is true to say then that RISC OS does not support digital output?

No, but it is true to say it doesn’t on the Iyonix.

Time to look at hanging a USB floppy off a NAS and trim all the machines down methinks.

A USB floppy drive will not help you with Acorn floppies. Unfortunately standard USB floppy drives assume the lowest-numbered sector is numbered one, and Filecore starts at zero. Well-known problem, I’m afraid, which cannot be solved in software as the protocol just does not support it.

A USB floppy drive will not help you with Acorn floppies. Unfortunately standard USB floppy drives assume the lowest-numbered sector is numbered one, and Filecore starts at zero. Well-known problem, I’m afraid, which cannot be solved in software as the protocol just does not support it.

Which pre-supposes the need to read Acorn floppies.
I suspect most old time users, even the oldies like me, have converted to those new fangled hard discs or those stick thingamies.

The main source of floppies for some while has been PC to PC/Acorn transfer. Most discussions on csa.* seem to involve transfer by wire rather than removable media.

Filecore starts at zero. Well-known problem, I’m afraid, which cannot be solved in software as the protocol just does not support it.

The more fundamental problem is that there is no USB floppy drive out there that can read 1024-byte sectors.

The problem could, in principle, be solved in firmware, but the practical difficulties are overwhelming.

Everything can be solved in software.

Not if the hardware doesn’t let you solve it. The UFI spec requires the host to specify disc addresses in LBA format. According to the spec, the device can then convert these to sector/head/track addresses using the following formulae:

Sector = (LBA mod SectorsPerTrack)+1
Head = (LBA/SectorsPerTrack) mod HeadsPerTrack
Track = (LBA/SectorsPerTrack)/HeadsPerTrack

Presumably Filecore is talking to ADFS which is talking to the USB device via DeviceFS? (Or is Filecore talking to DeviceFS directly?). Either way, there is an opportunity to have something in between to remap the sector numbers.

FileCore talks to SCSIFS which talks to SCSISwitch which talks to SCSISoftUSB which talks to DeviceFS which talks to USBDriver which talks to EHCIDriver/OHCIDriver/MUSBDriver/DWCDriver which talks to the USB controller which talks to any number of hubs which talk to the USB floppy drive which does the LBA to sector/head/track conversion. So unless you can rewrite the firmware of the USB floppy controller, or the firmware is buggy, you won’t be able to access sector 0 a floppy using a standard USB floppy drive.

The more fundamental problem is that there is no USB floppy drive out there that can read 1024-byte sectors.

I initially thought the same as you, but closer examination of the spec reveals that 1K sectors are supported (see medium type code 93h). You can even specify your own sector size, using the flexible disc mode page (Although there’s no guarantee whether any settings which don’t match one of the builtin media types will work)

Admittedly this is not an off-the-shelf USB floppy… but it is a USB floppy that can read Acorn discs: http://www.kryoflux.com/

The problem could, in principle, be solved in firmware

Agreed, but too late now.

see medium type code 93h

1.25 MB formatted capacity?

1.25 MB formatted capacity?

Well, I didn’t say it was a particularly good example of a format with 1K sectors.