Jocki's Personal Tips and Tricks

General

Memory Test

Always test your new computer memory with a good memory test program. I prefer memtest from Alexander Grigoriev, that does excellent stress testing under adverse conditions and has proved many SIMM modules defect here at work. Even if HIMEM.SYS or the BIOS test have not reported any problems but the system was unstable, it was shown that the memory had certain defect bits, even new modules we just bought.

You can download it from the authors home-page AleGr, or from a local copy from me here

Another program is called memtest86 and can be downloaded from memtest86.

Linux

CDRecord

With the following command, it is possible to write a multi-session CD under Linux with a Sony CDU-924S (tested without the '-multi', creating a single session CD only -> not writable again!)
```
cdrecord -v -speed=2 dev=0,6,0 -multi -data cdfile.raw
```
Command for writing a first session on the fly from a src directory:
1. Test command with dummy:
```
mkisofs -R -J /master/tree | cdrecord -v -speed=4 dev=0,4,0 -multi -data -dummy fs=20m -
```
2. Real command: don't forget the '-' at the end which accepts the track from stdin
```
mkisofs -R -J /master/tree | cdrecord -v -speed=4 dev=0,4,0 -multi -data fs=20m -
```
Writing subsequent session on the fly from a src directory:

First you need to get the info about the previous sessions from the CD-R by issuing:
```
cdrecord -msinfo dev=0,4,0
```
Then you take the last two numbers of the output and supply them to the "-C" command of mkisofs. They are the beginning sector of the last session and the starting sector of the next session. In this example 0,109098.
```
mkisofs -R -J -M 0,4,0 -C 0,109098 ./ | cdrecord -v -speed=4 dev=0,4,0 -multi -
```
Note: the options "-R -J" add Joliet and RockRidge extensions to the CD-R, such that Unix and Windows systems can read long filenames etc.

CDRecord is very sensitive (as many generic SCSI devices) to kernel version changes. Be sure to compile a new for every major kernel change (here: 2.0.x -> 2.2.x). Below is the error message for using cdrecord with the wrong kernel!!!!

inspc48:18:16~#cdrecord -dummy -speed=2 dev=0,6,0 -data -isosize /dev/hda7
Cdrecord release 1.6.1 Copyright (C) 1995-1998 Jörg Schilling
scsidev: '0,6,0'
scsibus: 0 target: 6 lun: 0
Device type    : Removable WORM
Version        : 2
Response Format: 2
Capabilities   : SYNC LINKED 
Vendor_info    : 'SONY    '
Identifikation : 'CD-R   CDU924S  '
Revision       : '1.1d'
Device seems to be: Sony CDU-924S.
Using driver for Sony CDU-924 (sony_cdu924).
Driver flags   : SWABAUDIO
Starting to write CD/DVD at speed 2 in dummy mode for single session.
Last chance to quit, starting dummy write in 1 seconds.
cdrecord: Cannot allocate memory. Cannot send SCSI cmd via ioctl

Hosts File

a hosts file must contain complete host names, not only 'inspc48' but 'inspc48.ins.uni-stuttgart.de' instead.

Compiling EGCS to a different location

Unpack the sources from Cygnus (egcs home) or a mirror site (e.g. cygnus at ftp.gwdg.de) to a src directory.

Then do the following:

mkdir objdir
cd objdir
../configure --prefix=/own --enable-shared
make CFLAGS='-O2' LIBCFLAGS='-O2' LIBCXXFLAGS='-O2 -fno-implicit-templates' bootstrap-lean

To install it beneath /own, just do a make install.
Last, you have to make sure to get the correct gcc by renaming one, e.g. the one in /usr/bin/gcc to /usr/bin/gcc2.

Xfig: fig2dev doesn't work anymore with newer version and error: couldn't find "C.ps"

just create an empty file /usr/X11R6/lib/X11/xfig/fig2dev/C.ps and fig2dev is happy.

ATAPI Zip drives don't behave like SCSI Zip drives

You probably have the Zip drive run as a Floppy in the BIOS Setup and not as a hard disk (SCSI Zips are usually hard disks). Therefore the BIOS eats the partition table and starts the Zip after the first 16384 bytes, where usually the first partition begins. Either change the mtools to not use an offset when accessing the Zip or make the Zip again a hard disk in the BIOS.

EUR currency in Linux

Using the EURO currency € in Linux means two things:

in the console: select the latin0 font: CONSOLE_FONT="lat0-16.psfu" and choose an EURO compatible locale, e.g. de_DE@euro
in X Windows and XEmacs: add a line to .xinitrc with
xmodmap -e 'keycode 75 = EuroSign cent'
and change all fonts that you use to iso8859-15 instead of iso8859-1 (most of them are defined in .Xdefaults). Then for XEmacs (that doesn't know 'EuroSign') in .xemacs/init.el
;; eurosign (define-key global-map '(currency) '[€]) (define-key global-map '(EuroSign) '[€])

BTW: if your browser isn't clever enough, you won't see that € is the actual symbol in these places here already. So check also what the HTML source looks like. Any occurrence of € is the actual character.

OS/2

Booting from a SCSI Zip drive (Rescue system)

Repartition the Zip disk with fdisk/fdiskpm. Delete the single primary partition. Then create a single extended partition on it and leave the (automatically created) primary partition alone. Make the logical drive/extended partition bootable and add it to the boot manager menu with a unique name.
Use BootOS2 (download directory at LEO, look for btos2xxx.zip) to create the boot disk on the Zip drive (have the OS/2 installation disks handy!).
Add all the utilities you want on the disk manually in a separate directory. Don't forget the corresponding DLLs, e.g. the emx??? DLLs for many Unix utilities.
Check the entries in the config.sys for their consistency. Take care to include the IFS=... line when using the ext2 file system driver for OS/2, as BootOS2 doesn't add it. Add your utility paths to the LIBPATH, and the PATH statements. Decide if you have enough memory (more than 32 MB sounds safe to me) to switch swapping off, so as not to load the Zip drive with the unnecessary SWAPFILE by adding or changing MEMMAP=noswap.
Whenever you want to boot from this Zip disk, make sure to switch the option in your SCSI controller BIOS called Treat all removable drives as fixed drives, or similar to ON. Only if the BIOS knows about the Zip drive, the Bootmanager will display the boot option. This is a drawback, but the only possible way to my knowledge.
Remark:If you had left the primary partition on the Zip disk then the drive letter would shift in front of your logical drives of the primary hard disk(s) and would mess up all drive letter assignments. This would be very hard to adjust for and should under all circumstances be avoided. The extended partition/logical drive remains at the end of the drive letter assignment order and therefore doesn't affect your hard drive partitions.
You are done and you should have a bootable Zip disk for rescue purposes handy. Just switch the Removable drives... option in the BIOS off and on for normal and rescue operations respectively.

Joliet Support in OS/2 Warp 4

If you have Fixpack 4 or later then you can enable Joliet (beta) support by adding the /W switch to the CDFS line:

IFS=C:\OS2\BOOT\CDFS.IFS /W

How do I revert my Warp Server system from HPFS386 back to HPFS?

These two HPFS file systems are virtually the same, except for the following:

The CONFIG.SYS file, the statement is HPFS.IFS rather than HPFS386.IFS.
The HPFS386 partition will have HPFS version 2.4 marked in the superblock as opposed to 2.2 or 2.3 for regular HPFS.
You will need to process each HPFS386 partition using the LAN Server tool PREPACL to remove the imbedded Access Control Lists (ACLs) and save them in a standalone file for possible later use. PREPACL needs to be run before booting using regular HPFS.

Note that the largest cache size for regular HPFS is 2 MB, so be sure to review your HPFS.IFS statement for valid parameters.

OS/2-Festplatte klonen (von: Michael Eckert)

Ich klone mein OS/2 auf eine neue Platte immer mit "XCOPY C:\ X:\ /s/e/t/h/r/v". Dabei starte ich von Disktette und partitioniere und formatiere die neue Platte zuvor von dort. Das ganze dauert vielleicht länger, ist aber noch nie schiefgegangen. Abschließend kann ich dann die Platten so anschließen, daß die Lauferwksbuchstaben wieder passen.

Ich benutzte zusätzlich immer den Parameter /O, da OS/2 manchmal alte Dateien reanimiert. Den Grund kenne ich nicht, bzw. ich kann diesen nicht reproduzieren.

micha

Java

Running Package Classes

If you get a whole Java package and want to run it, you have to adapt your CLASSPATH and then call the Java interpreter to run its primary class's main() method.
Assume you unpacked the package Pack1 in /tmp and it's primary application class is called App1, then you would do the following
```
setenv CLASSPATH $CLASSPATH:/tmp
java Pack1.App1
            
```
to run it (assuming CLASSPATH is already set), i.e. set the CLASSPATH to the base of the package directory. The Java interpreter then looks for the class in the package directory plus the class name. The . (dot) of the complete class name stands for the / (slash) in the path. The above line means: "start class App1 from subdirectory Pack1".
If you still get an error message that java can't find the specified class or one of its dependents, then you might miss some basic class from which the one that is started was derived (OO-inheritance). E.g. you might have the wrong version of swing (1.1 instead of 1.0.3) or any other fundamental class set. Try checking the base class for the one you call, i.e. the class after the keyword extends in the java source file.

Graphics

How to Use Gimp to Make an ImageMap

Go to the image and select Filter -> Web -> ImageMap and follow the dialog window.
Select a selection tool
e.g. click the desired polygone outline and close this with a double click
Then specify the desired URL for this area
Repeat this for all areas
Save this into a file: this creates the HTML source code including an absolute link to the image you were just using.
Change the link in this file accordingly