All items...           Popular tags: Linux (9), Electronics (7), Hack (7), DIY (5), Debian (5), Other (4), Curiosities (3), Retrocomputing (3)


Weak passwords and weak resources

2017-03-14 20:04:31,  In: Security, Other

In the last few years, questions about password complexity emerged from time to time. There are list of common passwords, they are counted in leaked daabases, in hashed and unhashed forms. Blog entries are usually alarming about the poor complexity and length of passwords. Recently, a Password rules are bullshit post on Coding Horror blog shows how password rules are bad idea. However, they seem to be insecure in totally ignored mechanism having nothing to do with their length.

To illustrate this problem, let me tell a story about graphics card drivers. In 1997, to download a new driver to my video card, I could do the following thing:
1. Go to my card manufacturer's website
2. Click Support, then Downloads
3. Connect to FTP in "pub/drivers" directory, or select board from the list
4. Download driver for my OS. Mission accomplished, driver in my disk.

20 years later:
1. Go to my...

... Read More


A hole in the casing

2017-01-30 20:50:00,  In: DIY, Retrocomputing

Sometimes old computers come with broken plastic parts. When only cracks are present, it's easy - we can fix them with glue or staples melted into plastic using soldering iron. Even totally broken casing can be fixed this way. The bigger problem is when the casing lacks some part which cracked off. Recently I purchased an old computer with broken front panel. From photos it can be seen that damages aren't so big and two parts can be glued together, but if you look closer you will notice that a whole bottom-left corner of panel is missing. How to fix it?


I decided to try with hot-melt glue applied from pistol-type hot glue applicator. First, I found that front panel is made of porous, well-glueable plastic, so I glued broken parts together using cyanoacrylic glue. I found that this panel is painted with something similar to white acrylic paint. Next, I started to apply hot-melt glue to form a patch. The key factor here is temperature. The glue comes from the gun very hot. When hot, the glue is liquid...

... Read More


Windows 98 - fixing file operation delays

2016-12-24 04:12:59,  In: Hack, Retrocomputing, Windows

Another text from series "Notes to myself". After installation of Internet Explorer 6 in Windows 98, some weird things may start to happen. It starts when large amount of files are deleted, moved or copied. After this operation every refreshing of explorer window related to renaming, moving, copying or deleting causes a minute hang of Explorer window. This persists until restart.
This is caused by a bug in Internet Explorer 6 shell, which is totally harmless in NT-based Windows systems, while in Win9x causes hang. And although MS has been notified about this problem since 2002, they haven't released any patch. The only thing we can do is to replace the part IE introduced to Explorer using the one from previous version, version 5.5.
But we have a IE 6.0! We need to use separate DLLs for IE and Explorer shell. So let's begin:
1. Obtain Internet Explorer 5.5 in Your language, CABs version, not a downloader which doesn't work. Using WinRAR, WinZIP or any other archiver supporting CABs, extract...

... Read More


Building Ted under Debian Jessie

2016-11-25 21:30:22,  In: Linux, Debian

Ted is a Linux rich text editor which has one significant good side: It is not bloated. It is written in pure C/C++ and offers everything a simple word processor may offer: Pages and margins, choosing font, attributes (bold, italic etc.), saving to text files, RTF and even simple HTML format. But the most important thing in TED is that it is not wasting memory and CPU cycles for useless things. Editors which need GTK require few GB of libraries. AbiWord likes to pull significant part of Gnome from repo. Ted is just working on basic libraries. It is possible to have a program to write being focused on writing without gigabytes of libraries! However, the biggest problem with Ted is that it is not supported anymore in Debian, as well as in many other distributions.

Unfortunately Linux is a system for programmers, and programmers like to write code. WYSIWYG software has no chance here to be maintained. So Ted became difficult to build. In this text I'll show how to build Ted in modern Debian Jessie...

... Read More


Making KiCad work offline

2016-10-26 18:22:31,  In: Electronics, Linux

KiCAD is distributed in many Linux distributions repository or as Windows installer package. Unfortunately most of these installation types have one problem - they don't install, or don't register, component footprint libraries. These libraries used by CvPcb are downloaded from Git repository each time user launches CvPcb. Although theoretical goal of this approach was to offer the user always fresh libraries, in practice it results in few minutes of lag (when the files are downloaded) and few hundred MBs occupied on disk each time. More, if someone used a library which is not available anymore, e.g. has been renamed or joined with another, there will be error message. Or maybe you don't have access to the Internet? So you won't design a PCB. Let's get rid of this Git support at all and use locally-stored libraries updated on demand. In this tutorial both Windows and Linux screenshots will be used.

   Windows version

After launching KiCAD, create a blank project and open Eeschema. Now open CvPcb by...

... Read More


So who made TH99?

2016-10-11 21:30:39,  In: History, Other

TotalHardware 99 is a great help for all of those who want to configure unknown PC component, board or drive. It is a website, now mirrored in many copies, which contains jumper settings for 18655 PC-related devices, from 8088-based XTs to Pentium II systems, the best ones in 1999. But who made it? Discovering, describing and documenting so much hardware required lots of time and resources (personally, for me this can be a really big fun). Some group or individual had to work with documentation and even real hardware, as some parts are named "UNKNOWN", usually the manufacturer and type is designated in documentation. Who is responsible for this site?
Let's see the history of TH99 in the Internet. It was popularized ca. 2001-2002 with a website of "A. Haning" (archived copy) who, as he wrote in his History page, found a free version of TotalHardware 99 without images. The file can be still downloaded e.g....

... Read More


Two ways to work remotely on Linux

2016-09-08 00:26:03,  In: Linux, Hack

At work, I have my Linux laptop and Linux workstation. Usually both are running. Sometimes I want to work on my small (12.1-inch) notebook using a nice Full-HD display and full-sized keyboard of my Workstation. Because both of these computers are in the same LAN and "see" each other IP addresses, I can use different open source solutions to connect them for remote control. Typical and well tested one is VNC (Virtual Network Computing) while older and not commonly used is X forwarding, popular in scientific software in 1980s and early 1990s (later replaced by proprietary client solutions). For some time I was working with VNC, now I switched to X forwarding. Here I'll show these solutions, their positive things and problems with them. All tests have been performed on Linux, a 64-bit Debian Jessie with TDE window manager (if you don't know, it's an older KDE). However, a test has been made to show that, contrary to common myth, it is possible to connect by X-forwarding using Windows...

... Read More


Programming PICs with Willem Programmer

2016-08-31 22:52:31,  In: DIY, Electronics

After replacing laser I needed a Modchip for my 20-year-old PS1 console. Following the "DIY" principle I downloaded an archive from Eurasia.nu with dumps of MultiMode 3 mod chip for PIC12F629. It contains even source code! I obtained a blank PIC chip and tried to program it in Willem programmer PCB v. 3. Of course Willem has no support for them. But it is still possible to write to the chip.
The first rule when programming PICs in Willem is to avoid Willem software. It is not well prepared for programming PICs. First of all, PICs have not only configuration bits (like AVR's Fusebits), but also factory-configured last 16-bit word called OSCCAL word. This word is used to calibrate internal RC oscillator and is set separately for each chip in factory, where RC characteristics are verified against real timing. So to program a PIC, you have to read it first, get OSCCAL value and program a new dump with old value good for the particular chip you have in programmer. It's really easy to erase OSCCAL with Willem...

... Read More


Using dead multimedia keys in Linux.

2016-08-20 20:46:22,  In: Linux, Keyboard, Hack

For years I was using a KeyMaestro keyboard connected to PS/2 port. This keyboard is a normal AT keyboard with a set of multimedia/Internet keys. When I switched to Linux, I decided to still stick with it as most multimedia keys were working OK.
But not all the keys. Let's try to make them all running.
First, you should know how the keyboard is used in Linux. The user presses a key, then the keyboard emits the code. Driver in Linux kernel emits the SCANCODE, and Linux program responsible for keyboard mapping maps it to KEYCODE. The keycode may be then used by the system (to be translated to letter as keysym, but we don't go up this level). This way many different keyboards for different platforms may be used by only altering the scancode-to-keycode translation method.
To make key do things we want, we must get its keycode. The most simple method is to use xev and, after seeing the window, pressing the keys. In the console, you will...

... Read More


Perl::Tk and "is not a hash" error

2016-08-09 19:23:13,  In: Linux, Perl, Debian

In Debian 8 (Jessie), after installing Perl::Tk, all scripts return the following error whenever Perl::Tk main loop is called:
2773678 is not a hash at /usr/local/lib/x86_64-linux-gnu/perl/5.20.2/Tk/MainWindow.pm line 53.
Line number may be different depending on Tk library version. Path usually will be different too (your architecture may differ), the most important thing here is this is not a hash error. The source of this problem is with using legacy form color parameter. In earlier X Window versions, colors responsible for window theming were stored as X Window system resources. This was never done completely in Linux, and the last desktop which done it in larger part was CDE from 1990s, and most Linux software just ignored parameters if there were any. However, some definitions survived until few years ago X have been updated. But Perl::Tk still needs some colour definition in order to generate a dialog window - it needs to know the background color.
To solve this problem, edit (or...

... Read More



Older posts...       Main page       Newer posts...