I wasn’t bad with programming BASIC, but the true epiphany came when I went on vacation to Spain (very common for UK kids). I took the programmers reference manual which not only had info about BASIC, which I already understood, but it included info on all the 6502 opcodes and all the c64 registers. It really took me a long time to understand what this was. It would have been much easier to have a mentor to help me through this… it was a reference, not a tutorial.
But at some point, it clicked, and I started writing out the assembly… there was a register to control the screen background color… so I just blasted 0 into that register to make it black. In what was probably my greatest ever fear of engineering, I then hand-assembled my two-line assembly into 5 bytes of machine code. But I had to wait until I got back from vacation to try it.
It worked… it changed the background color, but it crashed the machine… I had forgotten to add ‘return from subroutine’, after that it worked, and that was the beginning of my journey.
I regret not spending more on proper tooling early on. But all the good assemblers were cross-assemblers that ran on pc’s.
There’s was also a really good book by Raeto Collin West that went into more details, and that’s where I got some of the drive register info. There is a command you can send to the printer to dump its memory, so that’s what I did. (To get it’s ROM to see what it’s drivers are doing)
The printer was critical to being able to read through the assembly and annotate it. You learn how to read ASCII in your head, etc.
Actually, unless you lived in a big city or near a university getting any level of programming books was tough...
However, assembly was more common back then and really wasn't consider a 'black art'. It was just what you did. Also, 8 bits were a lot simpler to program (flat address space, no protected mode, etc) - at most, you might have to deal with some bank switching..
Even hobbyist mags like Compute! would run articles on assembly - and DDJ would have that fancy 'C' stuff too!
To add to the "simplicity" aspect, I'd add: They were tiny.
You could read the entire OS ("KERNAL") and BASIC disassembly start to finish (there were books listing them, with comments added). You could systematically test what changing registers would do - I remember pestering my parents at work by calling them to let them hear what sounds I managed to make by randomly POKE'ing things into the sound registers just to experiment.
And of course the manuals. While I agree with you books were hard to get, the C64 manual was fantastic.
Do you have any links to books with the annotated disassemblies of the kernal/BASIC interpreter?
To GGP: you should get an 8-bit computer and play around a bit, some things may blow your mind. I first played around with a C64 in around 7th grade, after I'd already learned some programming on PCs, and I learned a lot.
Oh! I should probably mention - Assembly was one of only 2 languages you were sure would be supported: you got ROM Basic, and an assembler. Later, you might get Forth,C,Pascal,Logo... especially if you could afford the 'big' CP/M or Apple ][ machines...Though those probably didn't have the ROM basic.
how did a teenager in that time period possibly get that level of technical introduction to things at that level?
Commodore published very detailed documentation for its computers, including schematics. You could buy these in most large book stores.
There was also lots of information available through local user groups, BBSes, BBS networks, and online services like GEnie, Delphi, The Source, and CompuServe.
Many local computer stores had regular meetings of their customers where people would exchange programs and information.
Youth shouldn't stop you, I walked into computer shops all day during my youth and I ended up with a job. This was early 00's, so Internet was there, and knowing a bit of HTML and how to reinstall windows was really all that's needed but -
Nowadays it's even easier with FB and such, just ask, and keep asking until you're satisfied.
Back then, it was the same, 80's, ask, community clubs, mailing lists, etc -
We're in tech, we communicate with one another, ask the right question and you'll get the right answer, even if it's questionable. ;)
There were magazines, and manuals were not too hard to find.
(These things had real technical manuals, with lots of internals described)
My personal experience as a kid is more oriented towards the Amiga, but I suspect it was quite similar.
One fun fact, the place I grew up was a minority language region, so specialized magazines/books were only available in the dominant language of the country which was not yet part of my of my school curriculum.
I ended up reading most of that stuff in German having absolutely no idea what that meant; a double puzzle to solve.
Italian in southern Switzerland. Big enough so you can grow up
listening and speaking it 100% of the time with little and no exposure to german/french, not big enough for newspaper/magazine distribution network to care about it (I'm pretty sure some fashon and general culture magazines were imported from italy, but not the Amazing Computing magazine...)
(Yes, I could have gone a few dozen kilometers cross the border to Italy to buy some, but I was a kid and my parents didn't indulge me further with this "toy")
Haha, we mostly didn't. I knew, roughly, what I wanted: assembly documentation, and a modem to find and talk to the people who knew. But I didn't have any of those things, and to be honest, it probably wouldn't have helped much if I had. The cracking/demo scene wasn't exactly friendly and accessible. Things are different today, with stars like LFT being very generous with explanations of how the magic is done.
But at some point, it clicked, and I started writing out the assembly… there was a register to control the screen background color… so I just blasted 0 into that register to make it black. In what was probably my greatest ever fear of engineering, I then hand-assembled my two-line assembly into 5 bytes of machine code. But I had to wait until I got back from vacation to try it.
It worked… it changed the background color, but it crashed the machine… I had forgotten to add ‘return from subroutine’, after that it worked, and that was the beginning of my journey.
I regret not spending more on proper tooling early on. But all the good assemblers were cross-assemblers that ran on pc’s.
There’s was also a really good book by Raeto Collin West that went into more details, and that’s where I got some of the drive register info. There is a command you can send to the printer to dump its memory, so that’s what I did. (To get it’s ROM to see what it’s drivers are doing)
The printer was critical to being able to read through the assembly and annotate it. You learn how to read ASCII in your head, etc.