Taligent

On May 13, 2013, at 3:05 PM, Nigel Williams <nigel.d.williams at gmail.com> wrote: Crap. Now I'm remembering all of the stuff about Taligent that I'd thought I'd forgotten. Here's a few of the "gems": - Reportedly it was really hard to port to new processors (they were on 68K). Why? One of the foundation objects was written in 68K assembler. It was needed to stream and unstream an object. It needed to know the object's size. A normal person would have said "put the size of the object in the object". Did they do that? Noooo. They had to be clever. They wrote a method that looked up "new" of the object, *diassembled* it and analyzed it to determine the size that new was allocating. Clever: yes, product quality: NO - They were extremely proud of the fact that they were *only* executing 6 (count them six) machine instructions between method calls. No work was getting done, just setting up for the next method invocation. - They had a messaging microkernel (just like we did...except theirs was *very* primitive). As such, messaging was fundamental to both OS's. They had decided that the fundamental object in a messaging system was a message. What that meant was that anything you wanted to do involved invoking a method on the message. So, if you wanted to say create a new task, you'd say something like msg(task.create) rather than something more sensible like task.create(msg). It may sound a bit esoteric but it was fundamental and their code looked really strange and made adapting it very difficult to situations that they hadn't originally considered. - They were based in C++. Everything had to be in C++ (except at the very bottom which was 68K assembler). This wouldn't fly for a number of reasons. The most obvious being that not all code that needed to run on this system was in C++ and wouldn't be re-written in C++. The thing that really nailed the problem was one of software updates. Because their object model was C++ it meant that if the object changed from one release to another everything using that object would have to be re-compiled...the OS, *all* applications, everything. - They created a TCP/IP stack. In C++. It was an interesting research project. I felt pity for the poor folks at IBM who actually had to take that code and make it work. I think eventually, they (the IBMers) gave up and took a version of the BSD stack and put the appropriate wrappers around it and called it a day. I think that's enough for now. TTFN - Guy