Going To The Dutch, Part 2: Henk Robbers (XaAES)

by Jos van de Gruiter

The Dutch programmer Henk Robbers has a nearly mythical status in the German Atari scene. Several web sites gave him the epitaph "sagenhaft" (legendary). He gained this reputation by finishing the freeware AES for MiNT: XaAES. Some months ago he stopped working on XaAES. What happened? For a second time MyAtari travels to Amsterdam on a hot day in August 2003.

Fame
Legendary? Henk is only a little amused when confronted with his reputation. It's not fame and fortune he's looking for. In fact, he did hesitate a bit to receive me. “I rarely have visitors”.

Television
The next story is hard to imagine in a time when everyone "wants to do something for television and become famous".

When Henk left secondary education in the sixties, he wanted a job. During one of his temporary positions he discovered the existence of computers and decided to become a computer programmer. He saw an advertisement in which a Dutch broadcasting organization asked for a "programmer" and applied. 35 years ago a lot of things were in a pioneering stage and you didn't have studies for everything. So it was possible for an inexperienced boy to receive an invitation. Henk travelled to Hilversum, the heart of Dutch radio and television.

During the interview it became clear that the word "programmer" has more meanings. The broadcasting organization was looking for someone to manage television programmes. But Henk was very clear. "No, I want to become a computer programmer". Even in those days Hilversum wasn't used to people who didn't seize this opportunity and the interviewer was amused by Robbers’ determination.

GEM fascination
Not long after this incident Henk started as a system programmer on a mainframe computer. He moved from Rotterdam to rival city Amsterdam. In the eighties he saw an Atari computer and fell in love. In this time when computers were commanded by keyboards, he immediately appreciated the GEM desktop and mouse-driven approach.

He bought an Atari, came home, switched it on and started using it, playing around with the mouse. A friend watched him and remarked, “I've watched you working with this computer for half an hour and you didn't touch the keyboard once”. Henk says, “He was used to computer users doing everything with the keyboard. The Atari was different and that was exactly what I liked about it”.

This fascination for GEM determined the direction XaAES took during Henk's authorship.

Orphan
XaAES is a multi-tasing AES for MiNT, the open source kernel for Atari. There are other AES implementations, like the commercial N.AES and the one that came with Atari's MultiTOS. The development of XaAES was started in September 1995 by Graig Graham. In 1998 the Swedish author Johan Klockars took over. A year later Henk Robbers started working on XaAES.

Jos: Why does someone writes an AES for a computer platform that is no longer in production?

Henk: Because it's fun. As a system programmer working on an AES appeals to me and I was looking for something to keep me busy. I knew XaAES from a public domain diskette, tried it, but it didn't work at all. In January 1999 I got connected to the internet and saw the sources were available on Johan's home page.

After downloading I took a look at the sources and I really liked what I saw, the way it was programmed. But it wasn't written very well. The first thing I did was try to make it look better in GEM.

Jos: January 2003 you stopped developing XaAES. What was the reason?

Henk: I never thought it would be so much work. After three years I became fed up with it. When a program gets better, it becomes more difficult to find the bugs. I discovered I've never had time for the things I would like to do with XaAES, like cascading windows.

Jos: What are the most important things you've contributed?

Henk: Get the windowing of dialog boxes really working and above all, the program hardly ever crashes. I think that is the most important thing, software must not crash, never.

[On Unix] You see, there are two sides of XaAES. The first one is GEM, that's what the user sees, the screen with windows. The other side is the way the program works together with MiNT. And there I fall short of the mark. I don't know enough about Unix and in the end, that's what MiNT is.

Other people have taken over the development, people who know more about MiNT. I never thought it very annoying that the system sometimes missed a keyboard or mouse command while debugging the GEM side. They seem to have solved this now, that's very interesting. No, I didn't try their first upgrade, I hesitate...

Jos: I've read on some web sites that XaAES was slower than N.AES. Is this still true?

Henk: Yes, that's because of a design decision, that makes the program more flexible for the author. The user won't notice this flexibility, but this construction made it possible that 99 percent is pre-emptible. This means that a task can be arbitrarily interrupted by any other task, XaAES being a task like all the others.

Another advantage is that XaAES is freeware and open source, where N.AES is commercial. XaAES will become a part of MiNT and in the end this OS will be as fast as MagiC. Some communication with MiNT could be twice as fast, when XaAES were a kernel module, offering tight integration.

It's not true that you need at least 14 MB RAM to use MiNT. If you just want multi-tasking, then leave all this Unix stuff out. You can use MINT.PRG, XaAES and Teradesk with some additional files and run it on a 4 MB ST, leaving enough memory to run some programs.

Charm
In the office room Henk has a TT and a Milan working, both on 17” flat screens. On the floor there's also a 19” mono screen connected to the TT by the Nova video card. “My first TT I've built into a tower. Some years ago I wanted a spare computer. I saw an advertisement of a printing company which had about ten TTs running Calamus for sale. I bought one and decided to leave it in its original case this time. I began to appreciate the charm of the TT’s design”.

PC
For surfing the internet Henk uses a laptop PC and he has a desktop PC with Linux installed. Recently he doesn't use the last one very much. “Most of the time I'm using computers for programming and the TT030 is still my favourite machine. Maybe I should use the PC more for that purpose, but I don't want to bother to learn everything again”.

Teradesk
Of course, Henk's Ataris are running with Teradesk desktop, another project he has been working on.

Jos: I've tried Teradesk and compared with Thing and Jinnee, it's pretty basic. I haven't discovered what more it can do than the standard TOS desktop.

Henk: It can run under a multi-tasking OS and it can have colour icons now. But you're right, originally it couldn't do more than a TOS 2.05/06 desktop, because it was meant to give the lower TOS versions the same functionality as 2.06. We needed a freeware, open source desktop to run under a multi-tasking OS and Teradesk was available.

Jos: Did you speak with Wout Klaaren, the first author of Teradesk?

Henk: No, I don't want to bother him. I wouldn't like it too, to be troubled with my abandoned programs. It's in the past and I don't want to think about it any more.

Jos: I've read on the internet that you've stopped working on Teradesk.

Henk: Nearly. When I was working on XaAES, we needed a multi-tasking desktop. Now I've given up working on the first, the other one isn't so important for me any more. However, recently I've been working on Teradesk together with Djordje Vukovic. To be honest, most of the recent development was done by him. After the next update he will carry on alone.

It's very funny. I'm 57 years old and people developing for Atari are 25 now. Many of them coming from Eastern Europe. They come with solutions we found out 30 years ago but were forgotten again.

Jos: The XaAES support site stated that you wanted to work on something else. What can we expect?

Henk: I'm writing an open source C compiler for Atari. It's based upon Sozobon C and will be compatible with Pure C. So it will be possible to use existing libraries. I've already tested this successfully. My compiler won't be as good or fast as Pure C, but you will be able to use it on an ST. I can't predict when this program will be released, but it's a nice job for dark winter months.

Good
There was a time when you could find Henk in the bars of Amsterdam. Nowadays he likes to walk in his neighbourhood. “I prefer this 19th century atmosphere here above the 17th century canal belt in the centre”. When he's not programming, Henk will be listening to modern classical music, designing loudspeaker cabinets or reading literature from his library. “I don't need computers for my personal well-being”.

MyAtari magazine - Feature #3, September 2003