Introduction & Welcome to the Retrocomputing devroom
When the Eliza psychotherapist chatbot was released by Joseph Weizenbaum, in 1966, people believed it real. Even the secretary of its creator thought the machine had feelings, as they discussed relationships and personal issues. But why? How could a simple computer text interface act so human?
In this session our speaker, a computer historian and associate at the Centre for Computer History, uncovers the workings of Eliza, the Eliza effect, and its impact in the modern world and films like "THX 1138" and "Her." From the computer hardware to the programming language, and the scripts used to simulate the human traits of empathy and comprehension, we look at how 233 lines of code was convincing enough to change the world... and then how that code was transmogrified into JavaScript so that anyone can read and understand it.
The talk covers an evolution of widget toolkits, which have been started 40 years ago along with the historical changes in a desktop GUI. Widget toolkits are reviewed from three points of view: architecture, user experience, and programming principles. More than 90% of historically significant widget toolkits have open source licenses: some are opensourced after decrease of their commercial demand (like OpenLook and Motif), others are developed as a part of FLOSS world (TCL/TK, GTK+, QT) or in systems cloned by the open source community (GnuSTEP, Haiku OS, etc.).
Reviewed toolkits of 1980s include early Unix GUI of Andrew Toolkit and Project Athena, followed by OpenLook and Motif, and main non-Unix toolkits: WinAPI and NextSTEP GUI. Significant toolkits of 1990s include TCL/TK, wide range of wrapper toolkits including MFC and Java AWT and Swing, and the appearance of two main Linux widget libraries, GTK+ and QT. Also the burst of visual theming occurred in the second half of 1990s is examined for Unix and Windows platforms (as in their artistic styles, so in used architectural approaches). The list of milestones is finished with the Apple Cocoa style, closing the XX century experiments (but theming efforts had 10 more years of boiling). From the architecture point of view, the talk covers the recurring efforts in the event processing techniques, targeting at hiding callbacks from a GUI developer with available object-style metaphors.
About one month after I was born in 1983 a company called MCI introduced their "Electronic mail" system. Originally a BBS-style system, where users dialed into MCI to edit, send, and receive mail. Users could send electronic mail to each other, send a physical letters, and even manage their telexes without ever leaving the comfort of whatever room they had with a telephone and an acoustic coupler.
It became necessary to have offline email clients. Rather than use SMTP or POP they came up with MEP2 (Message Exchange Protocol 2). MEP2 combines the functionality of SMTP, POP, and some LDAP features together.
In this talk I will discuss the history of MCI, MEP2 protocol, and the mail server I implemented that can speak it.
The Neo Geo, the classic cartridge-based arcade and home video game system turned 35 in 2025. By now, it has been thoroughly reverse-engineered and documented online. Recently, there has been a surge in homebrew demos and newly published homebrew games for the Neo Geo. And although development in 2026 is way easier than it was in the 90's, too many available tools are still GUI-only, closed-source or Windows-only binaries, which leaves a lot to be desired. ngdevkit [1] was born out of this observation. The ambition of this project is twofold: first, to be a fully open source, easy to use development kit; second, to prove that your entire game development workflow can rely exclusively on open source software for compiling code, creating graphics, composing chiptunes, designing sound FX...
This talk will give an overview of C programming for the Neo Geo with ngdevkit, and will discuss the main components of this open source development kit. ngdevkit provides a toolchain that leverages binutils, GCC, newlib and SDCC for code compilation, GnGeo or Mame for code execution, and GDB for source-level debugging. It also comes with an open source reimplementation of the original Neo Geo BIOS, with full ABI compatibility. In addition, this development kit provides the necessary crt0 and runtime to boot the game processor (68k) and the sound processor (Z80), and uses a custom linkscript to expose hardware features (video RAM, backup RAM, memory mapped registers, I/O state) as regular C variables. At last, it provides the first fully open source sound driver and chiptune player on the Neo Geo hardware. Throughout the talk, we will discuss how ngdevkit was made possible thanks to a vast trove of public domain documentation and a vast collection of open source software.
[1] https://ngdevkit.dev
In this talk we'll explore the fascinating world of emulators and recompilation, by building together a dynamic recompiler for NES games, which will translate in real time code written for the game system into machine code directly executable by our host computer.
The Z80 CPU has been extremely popular in home computers of the eighties, but as 16-bit and 32-bit processors became more popular, the only new computers built using the Z80 were continuations of some legacy lines (like the Amstrad PCW).
And yet, in 1999 a company named Cidco unveiled a completely new computer line named the MailStation. with a Z80 CPU clocked at 12 MHz and 128 kB of RAM. It was a specialized machine for sending and receiving emails, addressed at people for whom configuring Web access on a PC was too complicated. Yet it was still a computer, with a screen, keyboard, means of communicating with the outside world and possibility of running user apps. Most likely the last new Z80 computer ever designed.
In my talk I would like to present this machine, show how it can be hacked to run custom software, and encourage the audience to join me in documenting the machine and writing custom firmware for it.
MailStation emulator: https://github.com/MichalPleban/mailstation-msemu
Host appliation to transfer software to the MailStation: https://github.com/MichalPleban/mailstation-mailtransfer
MailStation hardware documentation: https://github.com/MichalPleban/mailstation-hardware
The first generation of computers (vacuum tube-based) emerged from WWII for scientific, military, or business purposes. In this pioneering time, the term “mathematical machines” was also used to distinguish them from human computers. This talk presents a working software simulator of the Belgian Mathematical Machine (MMIF), a little-known computer funded after WWII by IRSIA-FNRS and inaugurated 70 years ago at the Bell Company in Antwerp. We will show, including using the stepping mode, how it deals with programs and data using separate "RAM" drums (Harvard-style) and carries out computations with a high-precision floating-point calculation unit. You will discover the not-so-odd instruction set, coding style and how complex functions required for applications in ballistics and thermodynamics were implemented as a specific library. In addition to releasing the simulator as Open Source, the NAM-IP museum also publicly archived the available technical documentation.
Who needs to build their very own 8-bit homebrew computer in 2026? I'd say everyone should, especially if you work in IT! The Memo-1 is my personal attempt at understanding computers from the transistor up to the UI: a complete 6502-based system built from scratch, using a French Minitel as a smart terminal, with sound, joystick ports and an extension slot for expansions. In this talk, I'll share what I learned from building the Memo-1, from wiring the CPU and designing a simple bus architecture to writing a Minitel library in 6502 assembly. Beyond the nostalgia, it's been a fantastic hands-on way to rediscover and demystify how computers really work.
Dial-up was the main way to connect to the Internet back in the 90s. Unfortunately, within the time almost all of the dial-up service providers are shut down, because of obvious reasons. It used to connect our living room to the world via 56 kbps (or less) bandwidth rate, in comparison, modern broadband global mean is two thousand times faster. But sometimes we still need it to connect our legacy hardware to the world, retro (or lowres) computing purposes, sometimes even to circumvent censorship.
In this talk, after a brief on the dial-up connection and it's nature, notes and methods on running a personal dial-up ISP and connecting to it will be covered; starting from hardware requirements for both ISP and client side and the software stack for GNU/Linux operating system to run a dial-up system, using only free/libre software.
In the 1970s, interacting with computer systems through display terminals became common. In small systems and technical computing, the RS232 serial interface with asynchronous, ASCII based protocols became the standard. Business systems based on IBM mainframe technology, in contrast, relied on high-speed synchronous communication over coaxial cables.
Nowadays, connecting an asynchronous serial terminal to a modern computer can easily be done using a readily available USB RS232 adapter. A 3270 style mainframe terminal, on the other hand, requires special hard- and software infrastructure to be brought to life. This presentation examines how terminals communicated with computers, how IBM mainframes implemented these interactions differently, and how a 3270 terminal can be used today to access both virtual and physical mainframes over the Internet.
Session Outline:
https://github.com/lowobservable/oec https://github.com/hanshuebner/coax-tcp/tree/interface3/interface3