Commander X16

Hi

I am an "oldtimer" who started programming in 1979 when I was 13 years old. I got a Swedish made

8 bit Z80 based computer and have been programming from that point in time. I have worked in many

computer languages since then including BASIC, Pascal, Fortran, Cobol, Forth, C, C++, Modula 2, Standard ML,

Delphi, VB, C#, and F#. As for machine language I started with Z80, then 6502 variants, and later 68k, x86/x64 and

recently Arm chips. 



/Karl

What was your Swedish-made computer, if I may ask? I'm very curious - I didn't realise that homegrown Scandinavian 8-bit systems were being produced! Very interesting, Karl....

Probably Luxor ABC80 from 1978: https://en.wikipedia.org/wiki/ABC_80

Then there was ABC800 from 1981: https://en.wikipedia.org/wiki/ABC_800

And ABC1600 from 1985: https://en.wikipedia.org/wiki/ABC_1600

I came along a few years after you did, but I have "professional" or "extended amateur" experience with many of the same languages: BASIC, Pascal, Fortran, C, C++, Modula 2, and C#. As for machine language I started with 6502 variants, and x86/x64.

My favorite programming class I ever took was actually FORTRAN 77 (where I was later a TA), because the instructor taught structured programming in an inherently unstructured language. Up to that point all I knew was how to learn the syntax of a language, but that class taught me to think of programming more formally, so that I could write "structured code" even when writing something in assembly language (if I maintained discipline). Also a one semester class that exposed us to about a dozen languages to help us compare and contrast what they could do.

Welcome aboard!

Glad to see another oldtimer!

About Swedish computers...

The ABC-80 was popular at the time, though a little bit pricey. It was often found in schools. It was later "replaced" with the ABC-800 series, which was more for professional use. These are BASIC machines, much like C64 and such. The ABC-800 was really built like a tank, I think it would survive in a real battlefield, the ABC-80 less so, but it was totally decent.

The Jet-80 was also around, it used CP/M 3 and was a very nice machine. Full Z80 chip set including DMA and banking to provide more TPA (larger application program area, I think you got 60-61K).

All the above used Z80.

DIAB (who produced the ABC-80) later also made the DS90 which was a UNIX machine (DNIX). These were 68k based.

There was also the Compis ("Kompis" means pal or friend in Swedish, so it got a C for Computer, I think)  which was intended as a school computer, running the futuristic 80186. This one was not so successful.

Hi Karl, 

That is an impressive programming CV!

I was wondering how big the leap is from learning how to write machine language on 6502 variants to learning how to write machine language on X86_64 and arm chips. Could I ask for your ideas on that?

Thanks in advance!

Wouter

In my opinion, 6502 assembly is one of the easiest languages. There are few opcodes and even fewer registers. When that is said, that does not necessarily make it easy to program in 6502 assembly as you have to do a lot of leg-work your self.

x86- and later assembly has more instructions and more registers which means there is more to learn, but it takes away some of the leg-work needed for 6502 assembly like multiplication and division.

I have not really tried assembler programming for ARM.

In any case you need to know about the supporting chips in order to do anything really useful. On the Commander X16, that means knowing about VERA, the VIA's and so on. On PC, it means knowing about BIOS, RTC, Interrupts and so on. Or, if you are writing assembly targeted at an OS like Linux or Windows, it means knowing about calls to the kernel to get things done.