Welcome! I’m Alexios. I’m a semi-nomadic IT consultant with a specialisation in networking, security, open-source software of all types, and Unix. This is the latest incarnation of my home page (est. 1994 — how quaint).
I'm jumping the gun and updating the site with its new look. There's still some content missing that was present in older versions of the site, but the most visited bits are all here.
Πού θα βρείτε στο πληκτρολόγιό σας το ελληνικό ερωτηματικό, διπλή τελεία, άνω τελεία, ελληνικά εισαγωγικά, τόνους με διαλυτικά και άλλους δύστροπους χαρακτήρες, με οδηγίες πληκτρολόγησης για χρήστες Linux, Mac και Windows. Το πιο πολυδιαβασμένο ελληνικό άρθρο εδώ, που «κολακεύουν» (δια της αντιγραφής, αλλαγής και παραβίασης πνευματικής ιδιοκτησίας) πολλά ελληνικά blogs. Ίσως και το δικό σας.
Id est, a Sarcastic Bastard's Dictionary of Esoteric Sexual Practices, Paraphernalia & Diverse Arcana.
Also Known As, It's not Confusing—You're Just Stupid. Or Gay. Or Both. Probably Both.
This isn't a light bulb joke. But it could be, if you wanted it to. In a weird way involving advanced discrete mathematics and polyamorous math geeks. The thing on my mind today is what has been dubbed the ‘official mathematical equation’ for finding the number of polyamorous relationships among a group of people. For the past three years, I've been convinced that this is wrong, and I'm finally putting my proof (I hope) online.
Αρχαιολογικό εύρημα! Οι οδηγίες του play-by-mail παιχνιδιού «Blood 'n' Iron» απο τις αρχές της δεκαετίας του '90. Το βρήκα σε ένα αρχαίο backup. Το θυμάται κανείς; Το πρωτότυπο (σε Word Perfect) χάθηκε όταν crashαρε άσχημα το Stacker μου (αυτό το θυμάται κανείς;) Το ΒΝΙ δεν έγινε ποτέ κανονικό PBM παιχνίδι, αλλά για ένα διάστημα το τρέξαμε στην Acrobase όπου απέτυχε λόγω έλλειψης χρόνου από τη μεριά μου: σχεδόν όλοι οι μηχανισμοί του παιχνιδιού ήταν χειροκίνητοι!
This is the project log of the CFT project, updated as the project is being worked on. The changes aren't always published immediately, though.
This series of articles is a C language tutorial, focused on using C efficiently on Oric computers. The language combines a set of features which make it an excellent choice for most programming tasks, from system programming to Artificial Intelligence. Unfortunately, it was not designed with small eight-bit systems in mind. As a result, the Oric implementation of C is a cut-down version.
This is your chance to play with Befunge online. No interpreter needed! I conceived this Befunge toy in a feverish fit (one might say it was ill-conceived), and as a way to practice JavaScript (not my favourite programming language).
Emulate the CFT in your browser! This Javascript-based program emulates the CFT's front panel and processor at the microcode level and includes various sample programs, from the obligatory ‘Hello World’ to a prime number generator.
Δύστυχοι χρήστες Windows! Δε φτάνει που υποφέρετε από κακοπροαίρετα προγράμματα κάθε είδους, δε φτάνει που έχετε το πιο εκνευριστικό λειτουργικό σύστημα στην αγορά, έχετε και χάλια υποστήριξη για γλώσσες με «περίεργους» χαρακτήρες όπως τα ελληνικά. Αφού εμπεδώσαμε ωραία και καλά ότι χρήσιμα σημεία στίξης (όπως η άνω τελεία) είναι πολύ δύσκολα αν δακτυλογραφηθούν στα Windows, μόνο μία προφανής λύση υπάρχει: η αθάνατη ελληνική πατέντα. Και να η δική μου!
Convert ANSI graphics to bitmap images! This is a web version of my ANSI file rasteriser. Written in Python, it simulates a PC's text mode using different VGA text fonts and renders colourful BBS graphics, affectionately (if inaccurately) known as ANSI.
Some old GIMP Script-Fu scripts to ease common photo processing tasks on the GIMP. The scripts are Duotone, Photo Frame and Full Frame. If you're still using the GIMP for photo editing work, they may help you.
A short Javascript program to improve detection of users idling or away from their keyboards, which should in turn improve how online users are detected. The file works with both jQuery and Prototype. It autodetects which is available at load time.
Fungus is a prototype hardware specification of a funge machine, a microcoded CPU capable of interpreting funges at the (macrocode) machine code level. Why? Well, so far we've had Lisp machines and Fortran machines and these days, right about everything is a C machine. I want a funge machine (don't worry, the doctors tell me I harmless). This is based on an incomplete paper describing the architecture. It's perverted, it's baroque, it's vector-based, it's 18 bits wide and it was originally available in PDF.
Back in 1996 or 1997, the Oric Project had a number of logos in use, most of which were hand-made bitmaps or badly scanned from Oric documents or photos. When I took over the Oric Software Page for a brief time, I decided I needed a decent logo, and made one. I used a scanned document (I forget which), which I then traced with a nascent pre-1.0 Gimp. I made it into a TIF and released it to the Oric Project. Now, I find myself needing a vector one, so I traced the original again. This time in Inkscape. Here are the results. I have done my best to keep the Persian Flaws of the original, but couldn't help but correct a few issues here and there. Here it is; enjoy!
This is a retro reference card for the CFT Processor, showing some basic hardware information and a complete tabular description of the machine's instruction set. If you've used computers at the Assembly or machine code level before, this may be all the information you need about the CFT architecture!
Ένας αστείος αλλά ενοχλητικός αστικός μύθος λέει ότι οι γραμμωτοί κώδικες (barcodes) που απαντώνται στα περισσότερα καταναλωτικά αγαθά περιλαμβάνουν το αριθμό 666 στην αρχή, μέση και τέλος του barcode. Αυτό δεν είναι αλήθεια, και να γιατί.
This is a poster generated semi-automatically, showing the plan and progress of the CFT Project as of September 2012. Things have changed a lot since — from the set of boards to the logo, but it's still quite informative.
This is my MSc thesis, for the MSc (by Research) in Artificial Intelligence. The research examined the use of Rough Set Dimensionality Reduction to simplify the exceptionally massive datasets used in Information Filtering. The methodology was experimentally applied to the filtering of Usolicited Commercial Email (spam) with promising results.
This is a list of academic publications produced as a direct result of my research work in a past life.
Για να λυθεί για πάντα η απορία του εξελληνισμού του «emacs». Μην ακούτε τους βαρβάρους που σχηματίζουν ψευδείς ιστορίες για το όνομα του άνακτα των editors. Δεν είναι «e(editor) [with] mac(ro)s» και αηδίες για TECO και πράσινα άλογα. Ο emacs είναι ελληνική λέξη. Κλίνεται κατά το «άναξ».
This is my BSc dissertation, completed in the summer of 1997. For no-one in particular's delectation and amusement, I implemented a framework for Intelligent Agents, evolved using Genetic Algorithms, to learn about the user's Usenet reading habits, and suggest new and interesting articles in places the user would never think to look. The idea was for this to eventually become either a full-blown AI newsreader (decentralised), or an NNTP proxy with agent extensions (centralised).
Here's how to build your own fast USB/Serial-based EPROM/EEPROM/Flash programmer you have a spare Atmega microcontroller, FTDI cable or board and a few serial-in/parallel-out shift registers. The article contains schematics and platform-independent software.
This is a simple microcode assembler (or microassembler). It can be used to generate wide, horizontal microcode ROMs for relatively simple CPU architectures. Using a description of the microcode, it generates one or more ROM, EPROM, EEPROM, Flash et cetera images suitable for inclusing in a software emulator, a hardware device, or for use in a hardware description language such as Verilog or VHDL.
If you’re building complex hardware devices like home-designed CPUs, this may come in handy! Prototyping home-designed CPUs isn’t an easy task at all. One might say designing one is difficult, but let’s assume you’ve already done that. State machines and function generation can be a nightmare to debug. Once you’ve found the bugs, actually fixing them may prove to be even more of a nightmare.
You run a medium-to-large size MySQL server with lots of databases, possibly for hosted websites. You want to optimise your databases, but they are quite big. This script is for you: it maintains and optimises MySQL databases incrementally over the course of every week.
The second version of evRouter is a modernised version, essentially rewritten from scratch. It aims to be equivalent to evrouter, but breaks compatibility in favour of a new approach of doing things. The project is in the earliest stages of development, but a proof of concept version exists and works fairly well (modulo the obligatory bugs, warts, etc). I'm writing this short page to describe what my aims are, and to see if anyone is interested in providing feedback with feature requests or wishes. Here come the obligatory bullet points.
One of those flash obsessions that won't let go. A METAFONT-generated font to make basic Celtic knotwork.
This is a font and associated TeX package to typeset the Menasat syllabary in the conventional, left-to-right, top-to-bottom orientation. Making the font description itself was remarkably easy. METAFONT makes it very easy to draw letterforms, especially when emulating writing implements, which I was. The code to typeset latin transcriptions of Menasat wasn't quite as easy. I had to code a state machine for it, and that was the first time I ever used plain TeX for anything at all. The code can obviously be used inside LaTeX documents, of course.
The oldest surviving part of my first home page, circa 1994. I've generally nothing to do with party politics, but I find these parties amusing and weird enough to include here. For all you politics maniacs out there, I'm not judging concepts and claimed objectives! The criterion is obscurity and weirdness.
This is a branch of the X11 terminal emulator unicode-rxvt (itself a branch of the rxvt terminal) with several modifications to make it more useful for Roguelike development, as well as BBSing. It has 512 user-defined colours, uses Unicode fonts, can report all keyboard and mouse events (not just characters pressed), and is still a full-fledged terminal emulator.
unicode-rxvt
rxvt
Between the mid-Eighties and 1991, our home computer was an Apple IIe. This was a pretty much uncommon machine in Greece, and we had a hard time finding software and hardware for it. Thankfully, the Apple was a hardware hacker machine, and came will full documentation as standard. Full, in those days, included a description of the hardware that was detailed enough for you to build a replica of the computer. So the Apple was modified in a number of occasions. Many of the games we obtained needed a joystick to work ― very frustrating, considering the price of said hardware. I built a few different joysticks, most of which were ‘no parts’ devices from whatever I had lying about, including audio cassette cases to house the things (which obviously broke often).
Αυτό το άρθρο παρουσιάζει ένα ανεπίσημο λογότυπο της Acrobase σε SVG format, με τις ιδανικές αναλογίες και διαστάσεις. Η Acrobase έχει εκατοντάδες λογότυπα, αλλά σχεδόν όλα είναι διαφορετικές απεικονίσεις του ίδιου ιδεατού λογοτύπου. Την εποχή που τα λογότυπα σχηματίζονταν με το χέρι για text modes, κάθε λογότυπο έπρεπε να είναι διαφορετικό γιατί έπρεπε να λυθούν ζητήματα χώρου και συμβιβασμοί που επιβάλλονταν από το περιοριστικό μέσον της ANSI art και της ευχρηστίας. Τώρα πια που έχουμε bitmapped displays με τετράγωνα pixel και ψηλές αναλύσεις, απαιτείται ένα λογότυπο με συνοχή σε φόρμα και χρώμα.
Τα τελευταία πέντε-έξι χρόνια έχω παρατηρήσει μια κάπως πιο, χμ, δημιουργική χρήση των διαλυτικών. Εδώ μπορείτε να βρείτε τους επίσημους κανόνες και μερικά από τα κοινότερα λάθη που βλέπει κανείς, ακόμα και σε επίσημες ανακοινώσεις από υποτιθέμενους γνώστες της γλώσσας, με αρκετά χρήματα για να αγοράσουν ένα πρόγραμμα επεξεργασίας κειμένου με ελληνικό λεξικό.
Μετά απο μερικά χρόνια παρουσίας στην Acrobase BBS και (κυρίως) μετά απο πολλά πολλά μηνύματα, ο Stanley και ο Morgul συνέταξαν αυτό το FAQ για να βοηθήσουν τους νέους χρήστες και να διασκεδάσουν τους παλαιότερους. Οι πληροφορίες που αναφέρονται είναι, στο βαθμό των δικών μας γνώσεων, ακριβείς αλλά αυτό δε σημαίνει ότι έχουμε το αλάθητο του Πάπα. Ένα ιστορικό κείμενο για την ύστερη ιστορία της Acrobase BBS. Το μόνο πρόβλημά του είναι ότι θα μπορούσε να καλύπτει πολύ περισσότερο υλικό για πολύ μεγαλύτερο χρονικό διάστημα.
Διάφορα αντίστοιχα κωμικά έντυπα κυκλοφορούσαν στο Usenet τη δεκαετία του 90. Αυτό είναι μάλλον το πρώτο που γράφτηκε στα ελληνικά, και προοριζόταν για χρήση στην Acrobase BBS. Παρά τον εξαιρετικό λόγο σήματος προς θόρυβο της Acrobase, το ΕΑΠΚ έχει δει «ενεργή υπηρεσία».
Έχετε μάθει το bash απ'έξω, έχετε στήσει το καταπληκτικότερο Linux όλων των εποχών, δουλεύει υπέροχα, ψήνει καφέ, σας κάνει μασάζ, σφουγγαρίζει, μαγειρεύει και πηγαίνει στη δουλειά αντί για εσάς. Και μετά πάτε και κάνετε ένα από τα παρακάτω.
Trolling idiots through the use of the ancient and dark art of obfuscated shell scripting. Because sometimes you just have to.
You have a Debian, Ubuntu or similar installation, and your /var partition keeps getting full when you upgrade. The APT archive directory is getting full of old versions of packages. You now need a quick and clever way of cleaning up this mess, so only the latest version of each package remains.
This is a patch adding some extra functionality to the Linux USB touchscreen driver. It adds features useful in developing and testing applications on touch-screens, as well as the ability to reverse the x and/or y axes — not every tablet out there defines its axes the same way.
A while ago we bought a tape library with a barcode reader for work. Unfortunately, the preprinted labels that came with the drive weren't very good. We looked into getting custom-made replacement ones, but they were so expensive we wondered if they were made of platinum. So I set out to make a Postscript program to produce our own labels. This is the result.
Use this interactive exploration widget to map polyamorous relationships, and to examine their characteristics. This is used in my write-up for the so-called Poly Equation and is likely one of the nerdiest things I've ever done.
In 2003, I was presented with a lovely Logitech optical mouse (an MX500). It had a wheel (not an ubiquitous feature then), no fewer than eight buttons, and an excellent 800 cpi resolution. Unfortunately, Linux would see it as a 400 cpi device, and two of the buttons would echo the wheel motion. A bit of quick research on the web uncovered the sage advice ‘you can't do anything about the extra buttons, live with it’. It also uncovered a list of vendor-specific USB control commands for Logitech mice (proving yet again that the majority of Linux users are no longer producers but ― at best ― consumers).
For a few years, back in simpler times, I used Jon Atkins’ imwheel to get X11 to understand the many buttons on my old Primax mouse. Traditionally, X11 only allowed for up to six buttons, and mine had eight (two were used for wheel events, as always). Imwheel allowed me to translate the buttons X11 didn’t know about to key events (but not before I hacked it a bit).
This is a MediaWiki extension to show certain content within a specified date/time range, before a given date/time, or after a given date/time. It's useful in hiding content for planned work, announcements, et cetera. People who use their MediaWikis as simple Content Management Systems or personal sites may find this useful.
The weird block of text to the right of my most common email/Usenet signature is actually a program in the Internet's darling esoteric programming language Befunge (‘darling’ taken with a pinch of salt — it's not as feared as the insanity-inducing pit of horrors that is INTERCAL). And this is what it does.
You just bought a shiny new motherboard, but the Linux kernel doesn't recognise some (or all) of the on-board PCI devices. Don't panic just yet, this one's very easy!
Let's say you have a large collection of incorrectly labelled, or downright unlabelled MP3 files arranged in directories by artist. Each artist directory contains one subdirectory per album, with untagged files under them. You need these files ID3-tagged with some basic information, namely the artist and album.
You need to display Pascal's Triangle in a LaTeX document and whenever you hear ‘ampersand’ or ‘smallskip’, you go into a homicidal rage, leaving behind you a trail of viscera and blood-stained Lion Book pages. Also, you're lazy. Put that chainsaw down, this recipe is for you.
Here are some useful one-liner recipes to help manage Linux Device Mapper (sometimes also known as ‘software RAID’) devices. These are too short to warrant separate recipes. They're here because I need them for myself: no matter how many times I've done this, I always check again.
Soup! is a Befunge quine (well, nearly) with a twist: it uses its source code as a pattern with which to generate ASCII art. This makes it massively obfuscated to encode the shape of its output. The actual program is smallish, really.
You have a deep directory tree of files, and you need to flatten it into a single directory, so that there are no files in subdirectories, and all the files are in the same place. This is a quick shell command to do just this.
You need to generate Pascal's Triangle in Python, and you're lazy (an admirable trait). Alternatively, you're looking for a Pascal's Triangle generator that can show really high-ranking rows, ones with multi-hundred-digit (or multi-million-digit) coefficients.
This is a heavily modified version of the 8mm tape label template shipped with Amanda. There are quite a few new things here.
I have had a homebrew moon phase calculator for various LiveJournal (and similar) sites for a while. It's come to my attention that to this day, no-one does this. Strange, considering so many cultures base so much around the moon and a lunar calendar (unlike the solar Gregorian Calendar in prevailing use all over the world). So, without further ado, behold the moon phase calculator in S2!
This project aims to bring the power of DungeonSpawn to Python. (or maybe vice versa!) It originally started as a set of bindings for DungeonMaker, but my own needs steered it further down the road and prompted various extensions to the original code.
Kareltima is a small series of smaller roguelike games of no small inanity. Set in a supposedly mystical world, where Gandalf the Grey is in the fake ID business, pub landlords know their calculus, malacks roam the towns (beware!), and bored priests are, well, very bored. There are also inexplicably singing rings and mutant sjutvynheims, whatever those might be.
In the process of making Python Bindings for DungeonMaker, I came across various shortcomings of the original code. There were behaviours I wanted to limit or inhibit, and various features were missing. I went about implementing some of these, and code started accumulating. I eventually made the decision to fork the original source tree, and thus was born DungeonSpawn: a version of DungeonMaker with extensions.
A lot of people out there are looking for implementations of the A* (a-star) algorithm for game writing, myself included. Eventually, I gave up trying to find one that fit the bill, and wrote one myself. My needs were complex (and I didn't want a C++ version), so I wrote this as generic as possible, and I'm releasing it for public consumption. Bon appetit!
RSAR treats datasets by removing attributes that are unnecessary for a classification task. It performs greedy feature selection using various versions of the QuickReduct algorithm. It is useful in reducing redundancies in nominally-valued (i.e. discrete) datasets for exploration or as a preprocessing step to training machine learning algorithms on the data.
This small Python program converts ANSI art to raster images. It simulates a PC's text mode using different VGA soft fonts (or EGA, or the CGA ROM font) and renders colourful BBS graphics, affectionately known as ANSI (after the ANSI.SYS MS-DOS driver that rendered them back in the day).
DungeonMaker makes complex random dungeons according to the designer's specifications. They can be as random or as deterministic as you want. The complex, organic look of the generated dungeons comes from the use of Artificial Life techniques: tunnels and walls are built by a-life creatures moving around the map. This is a modernised build of the library, packaged for modern distributions of modern operating systems.
Η Acrobase οργανώνει περιστασιακές εικονικές συναντήσεις στην BBS (όχι στο web), για ιστορικούς και συναισθηματικούς λόγους, για να θυμούνται οι παλιοί και να μαθαίνουν οι καινούριοι. Το πρόβλημα με τη διαφορά μεταξύ παλιών και καινούριων είναι ότι οι πρώτοι δεν έχουν πρόχειρο modem, και οι καινούριοι δεν είναι 100% σίγουροι τι είναι modem. Αυτό το πρόγραμμα διευκολύνει τη σύνδεση στην Acrobase BBS και για τις δύο ομάδες.
This is a heavily modified version of the DLT tape label template shipped with Amanda, that includes various improvements for æsthetics and usability.
Μια έκδοση του ΕΑΠΚ προσαρμοσμένη στις ανάγκες της λίστας linux-greek-users, που για ένα διάστημα ήταν γεμάτη από άτομα που είχαν σοβαρή ανάγκη να δεχτούν από ένα τέτοιο έντυπο.
This is a convenient little hack based on GNU iconv. Unlike that utility, which converts files, TTYConv converts interactive sessions, performing lenient and error-recovering two-way conversion and taking care of other issues with interactive sessions.
Once, in the days when PDAs lasted a whole month on one battery charge, I had a Palm IIIx. I forget how many PDAs and smartphones I’ve had since, but the M68k-based, greyscale (mostly black & white), 160×160 little plastic box was probably the best PDA I’ve ever had, and the only PDA I’ve ever written software for.