Kalevi Kolttonen computers and logic page


Programming

Sendmail support for Cyrus IMAP IGNOREQUOTA LMTP extension (updated on October 13th, 2018)

Automated eBay searching using ebaysearch script (v0.3.0 released on November 11th, 2018)

B-em v2.2.3kk Acorn BBC Micro emulator (updated on February 21st, 2018)

Studying VICE 3.1 (svn r34431) Commodore 8-bit emulator (updated on February 10th, 2018)

SELinux demonstration using a malicious backdoored daemon (updated on March 18th, 2018)

Studying openMSX 0.14 emulator (updated on June 17th, 2018)

How to become a programmer? (updated on October 21st, 2018. Some advice for beginning programmers)

Segmentation faults and core dumps on Fedora Linux 28 (practical advice for C programmers)

Psychology of Computer Programming (updated on October 21st, 2018. Psychology is an extremely important field of science. In this article we will explain why this is so. We also summarize Gerald Weinbergs's early, pioneering insights that still have direct relevance to programming every day. I strongly feel that all programmers should pay attention to psychology!)

Clang 8 snapshot with a tiny CLANG_PARANOID patch (updated on December 22nd, 2018. This is a Clang 8 git snapshot mainly for my personal use, but it is available here in case someone wants CLANG_PARANOID tests for functions on Fedora Linux 28/29)

Sendmail 8.16.0.29 with PostgreSQL support (updated on January 19th, 2019. This is a testing snapshot of forthcoming Sendmail 8.16. As a strictly personal experiment, I have added an experimental PostgreSQL database map support. Please note that the PostgreSQL feature is not going to be in the official Sendmail 8.16 release, this is just my personal project and I doubt that the code would qualify for the official 8.16. My RPMs are available for Fedora Linux 29 and the patch is also downloadable here!)

ldapsockmapd (updated on March 8th, 2019. This is LDAP Socketmap Daemon, a real-world Unix daemon that provides socketmap database service for Sendmail MTA. It is my hope that ldapsockmapd could serve as an example of how to provide socketmap databases for MTAs, and also how to create custom SELinux policies for your own programs.)


Retrocomputing

Emulators

Atari 8-bit emulator atari800 for Fedora Linux (step-by-step tutorial on how to install atari800 emulator using my RPMs)

Amstrad CPC emulation on Linux using MAME (step-by-step tutorial on how to use MAME for Amstrad CPC emulation)

ORIC 8-bit emulator Oricutron for Fedora Linux (step-by-step tutorial on how to install oricutron emulator using my RPMs)

Colecovision emulator ColEm for Fedora Linux (step-by-step tutorial on how to install colem emulator using my RPMs)

Dragon 8-bit emulator xroar for Fedora Linux (step-by-step tutorial on how to install xroar emulator using my RPMs)

NEC PC-8800 8-bit emulator xm8 for Fedora Linux (step-by-step tutorial on how to install xm8 PC-8800 emulator using my RPMs)

Spectrum emulator FUSE, Manic Miner and Jet Set Willy on Fedora Linux (step-by-step tutorial on how to install fuse and play Sinclair ZX Spectrum 48K releases of Manic Miner and Jet Set Willy)

Texas Instruments TI-99/4A emulator ti99sim for Fedora Linux (step-by-step tutorial on how to install ti99sim-sdl TI-99/4A emulator using my RPMs)

Apple IIe emulation on Fedora Linux 29 using MAME (step-by-step tutorial on how to use MAME for Apple IIe emulation and playing some classic retrogames)

Tatung Einstein emulation on Fedora Linux 29 using MAME (step-by-step tutorial on how to use MAME for Tatung Einstein emulation and playing Manic Miner)

Miscellaneous

Commodore 16 herää henkiin (in Finnish)

Sekalaista juttua vanhan ajan tekniikasta ja peleistä (in Finnish)

Manic Miner on C16 and C64

How I experienced the home computer revolution of the 1980s in Finland

Introduction to retrocollecting

Boulder Dash

Boulder Dash Construction Kit

Commodore 64 - Tasavallan Tietokone kirja on julkaistu (in Finnish)

Miksi sama konekieliohjelma ei toimi koneissa, joissa on samantyyppinen prosessori? (in Finnish)

Kalevi Kolttonen's retrogame collection samples (mostly a bunch of clickable thumbnail images to remind myself of what I already have)

Sega Up 'n Down arcade coin-op game and its 8-bit ports (running Up 'n Down on Fedora Linux)

Manic Miner on ORIC (two essential training hacks for practicing this great ORIC release and some photos of the original tape release)

Manic Miner on Tatung Einstein (20 different disk images of Tatung Einstein Manic Miner to enable you to practice each of the twenty rooms this version has)

Manic Miner on BBC Micro (detailed explanation of figuring out two essential training hacks for practicing this great BBC Micro release)

Trollie Wallie platform game (this rare floppy disk release completes my C64 game collection!)

Commodore 64 Wizard of Wor with Magic Voice speech cartridge (testing with real Commodore hardware)

Tekniikan Maailma 16/1983 ORIC-1 review (review in a Finnish technical magazine, summary in English)

Tekniikan Maailma 20/1982 Atari 400 review (review in a Finnish technical magazine, summary in English)

Atari tools (atr) for Fedora Linux (Atari disk image utility, RPM and source RPM)

Franny for Fedora Linux (Atari disk image utility, RPM and source RPM)

Starting Atari 800 development on Fedora Linux (step-by-step tutorial on how to set up a cross-assembler environment for Atari 800 development on Fedora Linux)

ORIC Manic Miner videos (video tutorial on how you could complete the second half of ORIC Manic Miner)

Sega SC-3000 Sindbad Mystery (reminiscing old times in a true retro spirit using MAME. Also includes nice photos of real Sega SC-3000 software and hardware!)

Tekniikan Maailma 10/1984 ORIC Atmos review (review in a Finnish technical magazine, summary in English)

Tekniikan Maailma 2/1985 MSX comparison (MSX comparison review in a Finnish technical magazine, summary in English)

ORIC Atmos (mainly some photos of my boxed ORIC Atmos 8-bit home computer and of very rare ORIC Microdisc floppy drive!)

Tekniikan Maailma 3/1985 Middle-priced Microcomputers (middle-priced 8-bit microcomputers comparison review in a Finnish technical magazine, summary in English)

CP/M on Spectravideo SVI-728/SVI-707 using openMSX (step-by-step tutorial on how to get SVI-728/SVI-707 CP/M running under openMSX emulator)


Security

Firejail for Fedora Linux (both RPM and source RPM available! I try to keep this up-to-date. UPDATED: January 20th, 2019)

Secure private IRC server with Tor support (step-by-step tutorial for setting up a secure private chatting infrastructure using Fedora Linux 28. With little creativity, this article should be easily applicable on almost any Unix/Linux! NOTE: This article has been superceded by Untochat publication documents on October 11th, 2018. For further information, see Building a secure chat infrastructure)

Does adding an SELinux policy always improve application security? (Simple proof that although SELinux improves security in 99,99999% of all cases, there are situations where broken software combined with inadequate SELinux policy could make matters worse)

Building a secure chat infrastructure (a pretty comprehensive document describing how Unto Sten and Kalevi Kolttonen built Untochat)


Fedora Linux source RPMs and RPMs

Sendmail 8.16.0.19-2 alpha/beta snapshot with experimental FFR (For Future Release) DANE support enabled

To enable DANE at run time, you must append this to the /etc/mail/sendmail.mc

LOCAL_CONFIG
O DANE=true

Finally generate the /etc/mail/sendmail.cf and you are ready to go. NOTE: To reiterate, this is a Sendmail testing release so do not use in production!