Marek's Weblog

Samsung CLP-315W Printer — by Marek Behr — posted on Feb 20, 2010 07:46 AM — Mac

Small color laser printer is a challenge to set up

The Samsung CLP-315W printer includes color laser printing and wireless networking for ca. 200 euro; the setup is not very polished though.

There are some stories on the net from people who have not been able to set up the wireless networking for this printer, in spite of hours of work. The only way for the printer to join an existing wireless network is to configure it through its web interface, which is accessible—yes, via a network.

By default, the wireless interface is configured in ad-hoc mode, which makes it possible to see it on another computer, but apparently impossible to get to the web interface.

The network installation guide advises to connect the printer via Ethernet and do the web configuration that way. It even mentions that one should wait for printer to acquire an address via DHCP. What it doesn't mention is that the printer is seductively configured with static IP 192.0.0.192 and gateway 192.0.0.192, apparently for both Ethernet and WLAN (only one can be active at any given time?), which makes it impossible to automatically connect to any router.

At this point we are starting to look at supplied software. The software for Mac OS X uses VISE installer (remember that?) which helpfully offers to quit all running applications (yes, we used to do this in Mac OS 9), and promises to install not only the driver, but also a SmartPanel which will "constantly monitor printer status and provide updates".

After canceling the install, we find in the Mac_Printer/SetIP section of the installer folder a Java utility to set IP via a low-level protocol (UDP?). This requires entering the Ethernet MAC address of the printer (visible on the printed configuration page; press the button for 5 seconds to get it) and new IP, mask and gateway. In spite of some error message about illegal IP (what, different IP and gateway numbers?) the IP is set, and with some luck the (rather nice) web configuration page can be accessed either from a suitably-configured attached computer or via a router.

Only then, one can a) configure the printer to use DHCP, and b) set it to connect to existing WLAN (at b/g speeds only) and enter WPA or other password. Once connected, the printer is visible also via Bonjour services, and can use a driver provided with Mac OS X 10.6 without problem (there's no need to run the ghastly Samsung installer).

One final note: printing on scratch paper that may already have something printed on the back is not very successful, as the black areas from the back are visibly lighter on the front of the page.

Rooted X11 — by Marek Behr — posted on May 28, 2009 11:29 AM — Mac

Back to 1-bit background patterns

A giant leap for mankind - Mac OS X 10.5.7 update includes a decent version of X11 server from XOrg that restores full-screen X11 display (turn on in X11 preferences). Alas, xpmroot doesn't understand the new DISPLAY settings, and one is left with a desktop covered in a classic X11 weave from the times of the Reagan administration (or a solid color). It's kind of soothing.

Now that the official version uses almost the same server as as the leading edge version, one can feel better about installing the newest X11 package and getting all the updates to client applications as well.

Actually, a newer version of xpmroot is included in the Fink fvwm package.

Of course with an antique display, one needs a desktop clock to know how late it is. An updated dclock from Tim Edwards seems to fit perfectly.

jsMath Experiments — by Marek Behr — posted on Oct 05, 2008 04:02 PM — Web

Is jsMath the way to go for displaying TeX formulas?

The jsMath package is a Javascript that interprets TeX expressions and renders them in a half-decent way on the HTML page. Simple installation instructions for Plone are here. As always with Plone, simple instructions don't work at all. There are two big problems:

In our current Plone, there is no such thing as Site section of the Site Setup and no way to easily add Javascripts to the header. The hard way is to go to ZMI, customize /portal_skins/plone_content/document_view, and edit /portal_skins/custom/document_view to add the following code within the <head>...</head> tags:
```
<metal:block metal:fill-slot="javascript_head_slot">
<script type="text/javascript" src="/tex/jsMath/easy/load.js">
</script>
</metal:block>
```
That will load the script only from standard documents (not AT documents, not blog entries like this one, etc.).
The Javascript load.js must be served from the same host as the current page. Rather than dumping entire jsMath hierarchy into Plone database, it is better to override the Apache proxy configuration to allow certain directory to be served directly by Apache even within Plone URL. In httpd.conf, add the following before the main ProxyPass lines:
```
ProxyPass /tex/ http://hostname:8080/tex/
ProxyPassReverse /tex/ http://hostname:8080/tex/
```
to serve the tex top-level directory via Apache. Of course, any Plone page that may exist at /tex URL will become inaccessible.

With that, we can type something like: <span class="math">x^2 = 9</span> and see it as beautiful math... On a standard web page, not in a blog entry... Try this test page .

Cringely et al. — by Marek Behr — posted on Apr 09, 2006 05:26 PM — Web

Authority figures, back from the shadows...

There are few things as annoying as the U.S. custom of rehabilitation solely by the passage of time. A certain Robert X. Cringely writes regularly in a PBS online column, and yesterday, his opinion piece appeared even on the New York Times op-ed page. Apparently enough years have passed since the guy was caught posing as a Stanford Ph.D. (he took courses but didn't defend a thesis) and an ex-professor (he was in fact a teaching assistant) at the same school. The same is seen throughout public life: Gary Hart, Dick Morris, all seem to come back from disgrace after 5-10 years. They obviously have the right to live a normal and fulfilling life, but to opinion-making? Please...

Kerberos SSH — by Marek Behr — posted on Jan 05, 2006 05:01 PM — Mac

Occasionally, ssh to Mac OS X server doesn't work

Every now and then, logins from Mac OS 10.4 desktops to Hydra fail with a mysterious message:

Disconnecting: Protocol error: didn't expect packet type 34

This happens shortly after logging in to the client machine. After a while, ssh works again.

The reason seem to be the Kerberos tickets generated automatically on login. One day we should fix Kerberos; for now, the solution is to wait ~10 hours until those tickets expire, or (much better) get rid of them by using kdestroy. Then ssh uses normal authentication mechanisms again.

Networked Illustrator — by Marek Behr — posted on Jan 05, 2006 02:58 PM — Mac

Simple steps to happiness with Illustrator CS

Two bits of advice for Adobe Illustrator CS (11.x) in Mac OS X (Tiger) networked environments:

Install Adobe CS as a local administrator user, rather than as network user with admin rights.
In Preferences→Plug-ins & Scratch Disks dialog, change primary scratch disk from Startup to the other option (typically, local hard disk name).

Without the latter, attempting to use Illustrator as a network user with a network home (i.e., remotely-mounted) results in inability to save files, and a cornucopia of error dialogs such as: not enough memory, filter failed, etc. It doesn't make sense, but that's how it is.

Xserve Celeron? — by Marek Behr — posted on Oct 06, 2005 06:41 PM — Mac

Is Apple switching to Intel across the entire product line or not?

On one hand, the possibility of new power-efficient Intel CPUs in the Apple Xserve 1U enclosures is mouth-watering in one respect: Intel C and Fortran compilers, usually free for educational use, and producing nicely-optimized code. On the other hand, who wants to get rid of fast and cool G5 chips when you have tens of hundreds of them in a tight space... This InfoWorld article seems to say that G5 will continue to power the Apple high-end. At the same time, IBM is concentrating on what is possibly the first ever Celeron system to be called a server.

Presentation 2.0 — by Marek Behr — posted on Oct 06, 2005 08:59 AM — Web

Think different about presenting

Did you ever wonder if a standard conference presentation format can be replaced with something—er—more captivating? Watch a bit of this keynote:

Dick Hardt at OSCON 2005

Tiger Notes — by Marek Behr — posted on Apr 29, 2005 08:42 PM — Mac

Notes on Mac OS X 10.4

With the expected Mac OS X 10.4 Server installation on www, here are some things to keep in mind:

ArsTechnica discusses many of the new low-level features, including (finally) ACL support for HFS+ volumes. The ACLs need to be first enabled using Workgroup Manager app or via command line. Afterwards, chmod +a ... allows fine-grained access control, using a syntax much simpler than the one we're used to in IRIX. Viewing is aided by ls -le command. The ACLs are necessary for our CVS server to function properly.
The current Cisco VPN client 4.6.02 does not function at all under 10.4.
Update: The new 4.6.03 version is now available from the Leibniz-Rechenzentrum and from the RWTH Rechenzentrum. The VersionTracker page collects comments.

SimpleBlog 1.2.2 — by Marek Behr — posted on Feb 10, 2005 02:03 PM — Web

SimpleBlog product upgraded to 1.2.2

Since SimpleBlog 1.2.1 would not allow editing existing entries as soon as any local categories were defined, unreleased SimpleBlog 1.2.2 which fixes this issue was installed from CVS :

cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/collective login
cvs -z3 -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/collective co -R release_1_2_2 -P SimpleBlog

The newest version 1.2.3 could not be successfully installed.

SimpleBlog 1.2.1 — by Marek Behr — posted on Feb 06, 2005 09:31 AM — Web

SimpleBlog product installation under Plone 2.0

The SimpleBlog 1.2.1 product from the Plone Collective installed without problems on the CATS Plone web site. This was in contrast my other Plone test site, which continued to complain about PROJECTNAME not defined during installation... Various weblogs can be installed now in various portions of the site, for example in the Software area for news about CATS-developed software, or in Teaching area for updates about the courses. What seems to be problematic:

Editing text area is very small (5 lines). How to expand it?
After creating a blog with no categories, one can still add categories later, but then the existing blog entries cannot be edited, showing an error page instead. Global categories can still be added in Plone control panel.
Icons should be customized to match the rest of the site.
Each blog entry must have individual entry name. It will be hard to keep these unique. Other blogs automatically create date-based entry names.
Default blog entry format is HTML. How to change the default to structured text?

RSS feed is also provided; to make it even better suitable for RSS-aware browsers, one should also modify the page template and add a new head element.

Acrobat mysqld — by Marek Behr — posted on Feb 05, 2005 08:53 PM — Mac

Surprise after installing Adobe Acrobat 7.0 Professional on Bluebird

In top and ps -aux on Bluebird, mysqld kept appearing unexpectedly. Even after removing /usr/local/mysql installation (left over from old pMachine experiments). On closer look, the daemon was located inside Acrobat.app directory. It is apparently used for communication between Acrobat application and web browser plug-in - argh! Disabled "Check browser settings when starting Acrobat", and killed mysqld. Schubert PDF plug-in is much faster for displaying PDF in a browser like Safari in any case.

This is not such an important event. But it's a first test of the SimpleBlog 1.2.1 product from Plone Collective. Cannot edit any entries in an existing blog after adding categories, but otherwise, seems to work OK.

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