Thought it might be fun to blog all the ones I have had go sideways (a little bit) when they were supposed to go straight.  So in no real order they are:

• Front wheel drive car with use of handbrake..
• Front wheel drive car (no use of handbrake!)
• Rear wheel drive car
• Mountain bike (YAY FUNS!)
• Road bike
• Road Tandem bike ( )

I think the most scary was the tandem, there was a brief moment of ‘oh crap, this is going over’ which was audibly the thoughts of the stoker from her reactions at the time too   It didn’t we were awesome, no it wasn’t intended

I am not 100% certain if this is entirely the RISC CPU bug or MADMAC being a bit pants at alignment, but it is possible to generate ‘fun’ alignment issues in your code by simply adding or removing a nop (or other similar 16bit only instruction).  The instruction doesn’t need to be called even! that’s how much fun this is!

From what I can tell it seems that jump instructions are particularly fussy about where they are jumping to, so it is possible that by adding/removing a 16bit instruction you will move a jump destination into one of these ‘un-desired’ addresses and hey presto your RISC code suddenly stops working, or does something weird.  Even though you haven’t changed anything that should cause such behaviour.

So if you are playing with Jaguar RISC code and using jumps and sometimes it randomly seems to stop working but then work again, this could be the cause.  How do you find which jump is being affected? trial and error is my best method, or add a nop just after the code you modified (doesn’t need to be the executed code block), one at a time until your code magically starts working again :/

One day I’ll fully track this down and come up with some fix/work around.. probably   Until then, keep hacking!

After an hour and half of cycling although a bit tired I still had some left in me, so I am certainly improving   I think I am going to have to do a fair bit more on my solo bike to get ready for the Great Manchester Cycle (I have entered myself for the 52 mile time limited version!!).. I think I few 50 mile routes will need to be completed.. I think it should be do-able however.  Will be interesting to see how I do against other riders.

anyway, I really should try to scribble here more, so much has happened of late in so many different ways in my life and I didn’t blog any of it!! (although some of that would be a conscious decision to not blog it )

Coding wise, my work on the Sound Engine has progressed beyond my hopes! it isn’t complete and I have so many exciting ideas to add to it still, but there is a beta release out there!  Most exciting of all is that people are using it!  It’s an awesome buzz to see the logo for a project you have worked on stuck in someone elses project, reading reviews where people are complimenting the music of that project and thinking “My code is playing that!” brilliant.

Life wise has also been amazing, I have met an amazing woman (literally!)  and things are going better than I could have hoped in that regard also!  One of the many positives she has had on my life is rekindling my interest in cycling, so much so I am now cycling to work (not enough, but getting there), twice this week, would have been three times, except I was feeling pretty lazy this morning (and have a lot to do tonight). As well as cycling, I have started to take Skiing lessons, hoping to make use of my new skills with my new lady later in this year or early next year

So, in super summary, interesting stuff on the Jag, amazing woman in my life, lost a load of weight (20+Kg!), getting fitter, learning to ski, oh and embedded electronics and system development fun!  See a lot has happened..

Now I just need to try and manage all this and get some sleep in too!

The scenario: Connecting a new Brocade 5100 switch with no configuration to an existing Brocade 5000 based fabric that uses Administrative Domains (AD).  Both the new 5100 and the 5000 are running the same release of FabOS, the 5100 has nothing but the barest of bare configurations (it’s IP address and authentication credentials).  With the ports connected, a switch show on the switches yields the following for the ISL port between them:

5100

LS Attributes:    [FID: 128, Base Switch: No, Default Switch: Yes, Address Mode 0]

Index Port Address Media Speed State     Proto
==============================================
  0   0   0a0000   id    N4   Online      FC  LS E-Port  segmented,(AD VF conflict)

5000

Address Mode:    0

Index Port Address Media Speed State     Proto
==============================================
  0   0   030000   id    N4   Online      FC  LS E-Port  segmented,(AD conflict)

I have included the last line of the information block as it gives a clue, the 5100 has additional lines here and more features, FID relates to Virtual Fabrics, a feature not supported on the 5000 in this case (I suspect not supported at all on the model but am not 100% sure of this).

The big clue for me is the “(AD VF conflict)” a bit of Googling revealed that it is not permissible to use Virtual Fabrics and Administrative Domains, I believe VF is the new AD, and hence mutually exclusive.  So the fix?

Simple, disable one or the other.  Now as the established fabric in this case is utilising AD, I am not going to disable that (as much as I would love to bin it ) so disabling the VF on the new 5100 is the order of the day.  This is thankfully simple enough to do.

Use the command

fosconfig --show

to list all configured VFs and remove all but the default ones.  If you haven’t configured any, you won’t have any.

fosconfig --disable vf

will prompt you to confirm you wish to disable VF, this will require a reboot of the switch you are on, and a full reboot it is too, it will stop passing frames.  Once the reboot has completed, the switch should come back up and happily merge with your existing fabric.

Hopefully this will be of use to someone else, and as with anything I write on here, use this information at your own risk, I am not going to accept responsibility if you wipe out your companies fabric, or set fire to your gran doing this.

The core of the engine has been fully converted to the RISC based DSP on the Jaguar, with only support setup functions being called by the 68000.  Improved code has reduced it’s size and increased it’s accuracy, as well as removing the need for any look-up tables at this time (I have a suspicion I may not be able to maintain this for full module playback compatibility.. time will tell).

The latest release being worked on (0.18) has a completely rewritten sound rendering core, reducing code size whilst increasing performance and efficiency and also tolerance for bus latency!  Working in systems as ‘limited’ as these gives you a far greater appreciation for the finite capabilities of the machine.  Modern machines have so much slack available to them in terms of bus speed and memory buffers that these considerations just don’t enter in.  In the case of the Atari Jaguar the single memory bus shared between 5 processors running at 25MHz, you have to take into account that what you ask for from main memory may not arrive for quite awhile, adding buffering to absorb these delays is an absolute requirement, unless you want horrible distorted sound.  Of course these buffers are limited to only a few KB as you need this limited RAM for your program code and variables.

So, progressing and with plenty of ideas in the pipeline.

But watching those clips stirred the long slumbering desire to ride my bike again!  As she has been unused so much since having my original bike stolen in 2006, which really killed my buzz, I have decided to give her a full service and shock maintenance.  Extra handy as Evans are only across the road and the ONLY authorized Scott shock maintainer in the UK (license to print money? at £95 a shock, I think so ).

Last night I started the bike service of 2012 and have removed the shocks ready to take over to Evans tonight after work, during the 2 weeks that should take before I get them back I am hoping to have a good go at cleaning up the rest of the bike, ready for riding in 2012   Going to be uploading pics to the gallery here for anyone interested in pictures of a bike being tinkered with and cleaned

I am mostly pleased with my alternative solution to pad spreaders (which I forgot to buy when in Evans).. cone spanners & cable ties!

Anyone interested in having a look (fully documentated too! with example code!) it can be downloaded here

As the code to read the actual pattern data was so bodged and crufty and incomplete (anything that used more than 15 samples was never going to work), I decided to completely rip it out and rewrite, but adding in hooks for various bits along the way and knowning now what I didn’t know when I 1st wrote it.

Took me longer than I planned originally, but the final result was certainly worth it!  Adding effects to this new build is super simple.  There are 15 primary effects, with a further 15 sub effects.  For now I am concentrating on the primaries.  I therefor have a list of Addresses of the code to produce the desired effect.  To select the correct effect code the effect number is added as an offset to the address of this list, the program counter is then jumped to the address stored there (not before pushing the desired return address on the stack for the RTS at the end of the effect) and thats it.  When I come to write a new chunk of effect code I simply write it and then update the list of pointers.  Jobs done.

I still have around another 21 effects to code, I am quite pleased with the pitch slide effects I have coded tonight despite me being suspicious that these may be the cause of the out of tune behaviour and also being incredibly simple

To further the work on the player I have a more complex effect rich module to work through now, one of my old favourites back in the day.  It has already identified and helped me resolve a few bugs I wasn’t aware of.  Really enjoying this project

Some more cracks are starting to show in the less well planned code it is like building a wall ontop of a badly done foundation, the more you build the more the foundation crumbles and needs bodging to keep up.  The re-write to RISC will be fresh at least, all though lovely extra registers to play with should make this run even sweeter.

In addition to my volume success I finally twigged on the period values being used within the tracker files, and believe I have actually tuned this to play at the correct pitch now, making it sound even better!  I tried a different tune and this highlighted a load more bugs I need to fix (ignoring the additional effects it uses for now), and yet more crumbling code as well as illustrating a possible need for multiple format detection.

Going to finish up early tonight as I want more sleep and I also need to build a VTES deck for playtime tomorrow