Pizza is currently certified at Master level.

Name: Solomon Peachy
Member since: 2001-10-04 19:49:21
Last Login: 2016-09-23 15:17:49

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Homepage: http://www.peachyphotos.com/blog

Notes:

A human being should be able to change a diaper,
plan an invasion, butcher a hog, conn a ship, design a
building, write a sonnet, balance accounts, build a wall,
set a bone, comfort the dying, take orders, give orders,
cooperate, act alone, pitch manure, solve equations, analyze
a new problem, program a computer, cook a tasty meal,
fight efficiently, die gallantly.

Specialization is for insects.

-- Robert A. Heinlein, "The Notebooks of
Lazarus Long"

Currently residing in sunny
Melbourne,
Florida
, I'm employed by href="http://www.linux-wlan.com">AbsoluteValue Systems
to write 802.11 network drivers for Linux and other
miscellaneous embedded-type stuffs.

My main passion
these days is photography;
href="http://www.peachyphotos.com">here is the portal to
it all.

Projects

Recent blog entries by Pizza

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Progress with the Mitsubishi CP-K60DW-S and Kodak 305

As mentioned earlier, the Kodak 305 is a rebadged variant of the popular Mitsubishi CP-K60DW-S. Both models, along with their siblings (ie the CP-D70/D707/D80 and the Fuji ASK300), utilize a print engine that requires the host system to perform thermal compensation and other processing typically handled within the printer itself.

Not knowing how those algorithms work, these printers haven't been terribly useful under Linux, with the only prospect being a painful reverse-engineering of the Windows drivers.

A couple of months ago, Mitsubishi released a x86 binary-only CUPS driver for the D70 and D707 models. Other models weren't supported, and naturally this wouldn't work on other CPU architechures. Still, it provided a much more attractive reverse-engineering target, and as my interest came and went, I made slow progress.

Another wrinkle is that the CP-K60DW-S and Kodak 305 are slightly different from the others, to the point where my backend code was unable to print at all -- the printer communicates fine until the image data is sent over, and then nothing. All attempts to diagnose this further hit a dead end. That said, due to the unknown image processing algorithms, it was largely an academic exercise anyway.

Fast forward to a week ago. I lowballed a bid for a used Kodak 305 along with some unused media, in an "as-is, no warranty or returns" state. The printer arrived two days ago, and I got lucky; not only did the printer work, but it had about 140 prints worth of remaining media, far more than enough to get things going. An added bonus is that the printer had only logged 587 prints in total, a pittance for this kind of printer.

I quickly found and fixed a small pile of bugs, but successful printing still eluded me. I could find no differences in the data being sent between Windows vs Linux. Lacking a true hardware USB sniffer, I turned my attention to the enumeration to see if anything different was going on there.. and in the process I discovered something unexpected.

It turns out that these two printers enumerated differently under Linux than under Windows. Under Windows, only two endpoints were reported, one each for bulk input and output. However, under Linux, there were three endpoints; two for output and one for input. It seems that the backend was attaching to the second output endpoint, which accepted all commands, but not the actual image data needed to submit prints.

I'm at a loss to explain why the device would enumerate differently under Windows vs Linux; perhaps there's somthing funky going on behind the scenes and usbpcap only saw "cooked" data based on the driver's needs, whereas Linux's view more accurately represented the actual negotiation?

In any case, the backend now binds to the first pair of endpoints it finds, and can now print on all models of the printer family -- but the output is still unusably awful.

That success enables me to resume my reverse-engineering efforts, with an actual printer to test my experiments upon. Fortunately, the printers all use the same algorithms, differing only in a couple of tabular (CSV-based) data files. Inferring the internal data structures based on how the data flows into the system will be my next step.

Things are looking up, and perhaps sooner rather than later Mitsubishi's current printer family will be fully usable with Free Software. It's a shame this effort is even necessary, but I do love a challenge!

Syndicated 2016-09-02 13:22:23 from I Dream of Rain (free_software)

Netflix and Hurricane Electric's IPv6 service

For a few years now, I've used Hurricane Electric to get a native IPv6 tunnel to the internet. I've also been using Netflix streaming since it was first introduced. Life was good.

Netflix, on behest of its content suppliers, has started to crack down on folks using VPNs or proxys, because they're often used to work around artificial geographical restrictions.

A day or two, that blocked proxy list grew to include Hurricane Electric's IPv6 service, which I make heavy use of. Despite a US billing address, being physically located in the US, and using a US tunnel endpoint, Netflix treats me as an eeeevil bad person.

Their only advice is "disable your proxy", which is not an option as I have IPv6-attached servers that need to remain online.

Netflix's applications don't provide a way to utilize IPv4 only, which basically means I had to figure out a way to force netflix traffic to travel over IPv4. Ideally, I'd block the IPv6 AAAA dns lookups, but there's no simple way to do that.

However, one can just null-route the entire Netflix IPv6 address range:

    ip -6 route add blackhole 2406:DA00:FF00::/48

This will, after a little delay, cause Netflix to fall back to using IPv4, and all is well.

Ironically, being able to avoid this sort of BS is one of the reasons why Netflix was such a compelling service, but the balance is tilting back towards piracy providing a better overall user experience. Part of me hopes that the stats show a nice correlation between making legal services less useful and piracy rates going back up.

Addendum: About a year ago, my ISP (Comcast Business) rolled out native IPv6 service which by all acconts works quite well. Unfortunately, they don't offer a static IPv6 allocation, which renders the whole thing useless for my needs.

Syndicated 2016-06-04 12:41:06 from I Dream of Rain (free_software)

This is why ECC RAM is a good thing

    [2954432.978093] [Hardware Error]: Corrected error, no action required.
    [2954432.982285] [Hardware Error]: CPU:6 (10:8:0) MC4_STATUS[-|CE|MiscV|-|AddrV|CECC]: 0x9c5cc820001c017b
    [2954432.986453] [Hardware Error]: MC4 Error Address: 0x000000054a089400
    [2954432.990528] [Hardware Error]: MC4 Error (node 1): L3 data cache ECC error.
    [2954432.994525] [Hardware Error]: cache level: L3/GEN, tx: GEN, mem-tx: EV
    [2954432.998450] mce: [Hardware Error]: Machine check events logged

Who knows what was going at the time...

Syndicated 2016-02-24 02:08:18 from I Dream of Rain (free_software)

Sinfonia CHC-S6145 (CS2) and Ciaat Brava 21, working!

Over the past year, I've written a bit about the situation involving the Sinfonia CHC-S6145 printer and its rebadged sibling, the Ciaat Brava 21. To summarize, the printers worked but required use of a proprietary, binary-only library ('libS6145ImageProcess') to perform thermal compensation and other transformations to the image data in order to generate sane output.

To make a long story short, I set out to reverse-engineer how that library worked... and a couple of weeks ago, I succeeded, with my reimplemented library generating completely identical results.

After some back and forth with Sinfonia, I'm quite pleased to announce that my re-implmented library, called 'libS6145ImageReProcess', is now released to the public under a GPLv3+ license. Except for the differing name, it is a drop-in replacement for the Sinfonia library.

Just to be absolutely clear, Sinfonia is not responsible for this library in any way, and will not support you if you complain that the output is somehow deficient or your printer catches fire when you print images of Donald Trump biting the heads off of adorable kittens.

Now in order to actually utilize these printers, you'll need to compile and install three components:

  • Gutenprint 5.2.11 (just released!)
  • libS6145ImageReProcess library
  • Latest selphy_print backend code

I should have the necessary backend code in the Gutenprint development repo soon, but due to licensing complications the library will probably remain separately distributed.

Particular thnaks go to Sinfonia and Ciaat for providing documentation on the printer communication protocols, and Matt Koglin for his SinfoniaCam(tm) and many, many rounds of testing.

This has been a long time coming, and is the culmination of quite a bit of work. I hope it proves useful, and if you do purchase one of these printers intending to use it with Linux (or a more obscure OS), please let your Sinfonia distributor know. :)

Syndicated 2016-01-30 20:24:40 from I Dream of Rain (free_software)

Lifting the skirts of Kodak photo printers

You have to hand it to Kodak. They have been selling their workhorse 6850 dyesub photo printer for more than ten years, and are still actively supporting it with updated drivers and firmware. It's even outlasted one of its successors (the 605), which is no longer sold, yet is still actively supported.

One of those firmware updates led to a discovery that resulted in a flurry of hacking on the 6800/6850 and 605 backends, resulting in considerably improved reliability, robustness, and performance. As well as many bug fixes, both backends now support full job pipelining and vastly improved status and error handling.

So what had I learned? The Kodak 68x0 family are variations of the Shinko S1145 and the Kodak 605 is actually a Shinko S1545. Digging deeper into other Kodak models, I discovered that the 7000/7010/7015 are variations of the Shinko S1645, and that the 8810 is a Shinko S1845.

I'd done my earlier reverse-engineering work on these Kodak models before some kind folks at Shinko/Sinfonia sent me documentation on several of their printers -- So when I re-examined what I had previously figured out with the other docs as a reference, I discovered that from a protocol perspective the 68x0/S1145 models were 6" variations of the 8" S1245, the 605/S1545 and 70xx/S6145 models were very close to the S2145, and the 8810/1845 are apparently identical to the S6245.

This means that I should be able to support the 70xx and 8810 printers with only minor modifications to the existing backend code. Granted, until I can get my hands on any of these printers all of this is conjecture.

So, I'll re-iterate my call for testers for these printers:

  • Shinko CHC-S1245 (aka Sinfonia E1)
  • Shinko CHC-S6245 (aka Sinfonia CE1)
  • Kodak 8810
  • Kodak 7000/7010/7015
  • Kodak 605 (Need to ensure no regressions were introduced)

As my personal printing needs are very well met at this point and these are all fairly expensive models (especially the 8810 and 70xx series), I can't justify buying more printers just to try and make them work with Linux. Someone else is going to have to step up to help make this possible.

On that note, I should mention the S6145/CS2 (and the Ciaat Brava 21), where the situation is a bit more complex. The backend is already written and partially tested, but it currently relies on a proprietary library that is only available in binary form - and which I lack permission to redistribute.

I'm pursuing a multi-prong approach to rectify that situation. In order of desireability:

  • Obtain source code to the library
  • Obtain algorithmic documentation so I can independently re-implement the library
  • Obtain permissions to redistribute the (binary) library, and also get it compiled for a variety of ARM targets
  • Reverse-engineer the library so I can re-implement it

Let me just say that curiousity, in of itself, is poor motivation for enduring the the combination of tedium and frustration that comes from trying to reverse-engineer an opaque blob of x86 code.

Ugh. I need to get out more.

Syndicated 2015-09-01 21:40:31 from Solomon Peachy

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