SDHC adaptors...

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RWAP
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Re: SDHC adaptors...

Post by RWAP »

tofro wrote:Sometimes it's better to just use what you have at hand and have something that works instead of trying to make things better than they need to be ;) )
I agree - I would rather have hardware with working drivers, which can then maybe be built upon - isn't that in the true spirit of the QL and the QL Users and Tinkerer's Association?

Let's face it, the QL worked fine for quite some time, until Tony Tebby and Simon Goodwin showed (in their own ways) how the power of the QL network could be exploited further with fileservers and controlling another QL's screen!
tofro wrote:
RWAP wrote: 3) Would it not make more sense at some stage to use a more direct method of storing files on the CF card - maybe utilising the methods used by uQLX / QLAY or even Q-emuLator for storing file headers - in that way there would be no need to use a BDI container for QL files and access from third party systems would be easier.
Hmm. That would have made the driver even more complicated. Today it just about fits into the available ROM space. On the other hand - The method as it is now (transfer through an emulator) should actually fit the targeted user base much more - They never have to leave their known grounds.
True - I think Simon was coming from the point of view of someone that does not use Windows or MAC based computers - it will be interesting to see if the BDI driver gets ported to QPC2 and maybe even to QDOS Classic....
tofro wrote:
RWAP wrote: 6) Section 7 seems to fall apart after the third open parenthesis, which is never closed. It's as if it's about to describe a way around the BDI image approach but never gets round to it - rather saying that it is not worth even trying to use the 'native' mode.

Will look into this. And yes, this section tries to keep the targeted (see above) user base from using "native mode" in order to protect them from shooting themselves in the foot. We had quite a bit of discussion about this - But, in the end, decided to keep it as simple and safe as possible for the time being. There might - and probably will - be a manual addendum that is going to explain how to use QL-SD in native file system mode.
Perhaps the answer here is to avoid the reference to native mode completely in the main user manual, as it could be confusing. A separate appendix or even manual would be ideal to concentrate on native access and maybe the technical aspects of how the driver layers work together, so that others can develop tools or their own approach to drivers should they wish.
tofro wrote: The actual intention for the targeted user was(for the moment): Use copies of pre-created image files that come with QL-SD. We didn't want the average user go through the hassle of creating their own images. Simply copying a file will get you going.
May I suggest that a blank BDI image file is included and the manual can then just refer to using this file as a starting point. Just a thought though - what size do you make the initial blank image file - or will it automatically increase as it fills up with information?
tofro wrote:
RWAP wrote: 10) Section 15 says: "The source code for the driver can normally be obtained from the same
place that holds this manual." A link needs adding to the manual, as the source code for the driver is not actually available on sellmyretro.com (where the manual is) - are the sources now available?
That one is owed to the early stage where we are (Remember: The very first one is not even sold yet). This will be made available in due time. Promised.
Yes I understand that - I think Simon would have been interested in seeing the source code (you never know, it might persuade him to have a little play with what he can achieve also). The manual needs to refer to just the site where it will be made available in that case - does it make sense to add it to Dilwyn's site?


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tofro
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Re: SDHC adaptors...

Post by tofro »

Rich,
RWAP wrote: Perhaps the answer here is to avoid the reference to native mode completely in the main user manual, as it could be confusing. A separate appendix or even manual would be ideal to concentrate on native access and maybe the technical aspects of how the driver layers work together, so that others can develop tools or their own approach to drivers should they wish.
We didn't want to remove references to native mode completely in order to at least tease one or the other expert user into it - It still needs to be tested a lot in this respect. Maybe the manual needs to find the right balance in some places still. But it's work in progress.
tofro wrote: May I suggest that a blank BDI image file is included and the manual can then just refer to using this file as a starting point. Just a thought though - what size do you make the initial blank image file - or will it automatically increase as it fills up with information?
Most probably there will be not only one, but quite a number of empty (and pre-occupied with some essential software) BDI images of various sizes on the SD Card to cater for most needs.
And, no - The BDI file can't grow. Although it would be nice if it could. The QL-SD driver only has a (very) rudimentary idea of a VFAT file system (It basically can find the start LBA of a named file and that's it.) So it wouldn't be able to grow and shrink files. This would also most probably collide with the non-fragmentated image file requirement the driver has.
RWAP wrote: Yes I understand that - I think Simon would have been interested in seeing the source code (you never know, it might persuade him to have a little play with what he can achieve also). The manual needs to refer to just the site where it will be made available in that case - does it make sense to add it to Dilwyn's site?
We haven't decided on (or even discussed) the final location yet - could be Dilwyn's site, should he agree to host the sources (that would be a simple .zip file), but could also be something like Google Code or SourceForge - That would make online collaboration and versioning much easier. It would make sense to have one single community-hosted, versioned and maybe even officially released (in case we find someone to maintain it) of the driver. I can't imagine much worse than having several working (or worse: non-working) versions of the code flying around the net and drifting apart code-wise.

Regards,
Tobias


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Peter
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Re: SDHC adaptors...

Post by Peter »

RWAP wrote:I have had some feedback from Simon Goodwin on this
I just wrote a long reply, but when I sent it, the forum logged me out! :evil: Now everything is lost, and I have no time to type it all again.

Just three quick remarks:

At the moment, QL-SD owners can request the source code by email. Public release should not be far, I'd just like the time to possibly include (Super) Gold Card fixes, write decent copyright notice, select the right files and re-check the build. Tobias also has the source code and could do the release, should lack of my time become a problem.

As the driver does not use the QDOS/SMS Slave Block system, I would avoid using the term slaveing in the manual at all.

Buffering can not be completely avoided, ramdom access of very short pieces data of data would drastically degrade performance.

Peter


Paul
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Re: SDHC adaptors...

Post by Paul »

Just in case someone is interrested,
I added a short video to the auction, in low quality I'm afraid. Just to give a very little idea.
It can be found in the gallery tab.
Kind regards
Paul


RWAP
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Re: SDHC adaptors...

Post by RWAP »

tofro wrote: We haven't decided on (or even discussed) the final location yet - could be Dilwyn's site, should he agree to host the sources (that would be a simple .zip file), but could also be something like Google Code or SourceForge - That would make online collaboration and versioning much easier. It would make sense to have one single community-hosted, versioned and maybe even officially released (in case we find someone to maintain it) of the driver. I can't imagine much worse than having several working (or worse: non-working) versions of the code flying around the net and drifting apart code-wise.
Personally, I agree that Google Code would be good - I prefer this to SourceForge...

I agree it makes sense to use a system such as this to help with collaboration - especially if other SD interfaces are made available.... :)


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dilwyn
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Re: SDHC adaptors...

Post by dilwyn »

tofro wrote: We haven't decided on (or even discussed) the final location yet - could be Dilwyn's site, should he agree to host the sources (that would be a simple .zip file), but could also be something like Google Code or SourceForge - That would make online collaboration and versioning much easier. It would make sense to have one single community-hosted, versioned and maybe even officially released (in case we find someone to maintain it) of the driver. I can't imagine much worse than having several working (or worse: non-working) versions of the code flying around the net and drifting apart code-wise.
Regards,
Tobias
Of course I'd be happy to host the sources, if asked, although I think that the other methods might be better from the point of view of community collaboration. Should you decide to do that, please let me know and I'll link to it from my site to help people find it.


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Peter
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Re: SDHC adaptors...

Post by Peter »

Paul wrote:Just in case someone is interrested,I added a short video to the auction, in low quality I'm afraid.
Good idea. The video says more than 100 words. Thank you! :)


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Re: SDHC adaptors...

Post by RWAP »

Another very valid point has been made by another QL user about these various interfaces.

It is a plea to the developers to remember that some QLs are in tower systems - whilst the QL-SD designed by Peter Graf is probably the best option for this (especially if you want to be able to access the SD card directly), it brings the question what is the maximum length of the cable between the two units? It may be worth offering a version with a longer cable as a standard option.

Of course, many of these cased units contain an Aurora motherboard with a Gold Card / Super Gold Card - so hopefully the issue with these interfaces will be resolved - although it would be interesting to see whether an Aurora may impact on this at all.

There is also the question of THOR / Q40 / Q60 users - and whether any of the options will work on those machines, or maybe something could be born out of a QL design.


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Re: SDHC adaptors...

Post by Paul »

There will be no standard for a longer cable as this is completely untested.
Other length cables can be built to order as an extra.
I can make a long cable and test this if I find the time for this.
At the moment I have very limited time for this.
Kind regards
Paul


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Dave
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Re: SDHC adaptors...

Post by Dave »

I have done an SPI link that was 120cm long with ribbon cable based on a 20MHz signal. No problems.

I think you will be fine for any cable length that could reasonably fit inside even a large tower case.


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