Long ago, before access to the Internet was cheap and plentiful, and way before search engines made finding this kind of information easy, this was a priceless find for an aspiring low-level programmer. All the (semi-)common PC hardware and software documented in one place.
Endless hours spent exploring VGA hardware registers and trying to apply them for cool visual effects. Learning how the then-new 32-bit Windows interacted with DOS extenders, and trying to make a homemade - very basic - operating system that could do it, too. The thrill of writing a Terminate and Stay Resident alarm clock, and having it finally not explode...
I have very fond memories of the Ralf Brown's Interrupt List.
Linux system calls WERE 80h. If your code is still using an interrupt to access kernel functions then you've got problems. Syscall exists for the simple reason that interrupts are expensive.
I too have spent hours of assembly code on PC hardware. My freshly downloaded copy of the interrupt list has always been at my (virtual) side when designing tests or libraries.
I think that has been one of the very first and largest information collection shared for free on the internet.
Kudos to Ralf Brown and whoever participated in keeping the list compete, accurate and timely.
There was unloved informatics in school and loved informatics at home. Unloved informatics consisted of graph flow optimizations. Loved informatics consisted of EGA programming and IRQ interrupt handling for multiple keypress detection and other stuff. Both informatics were in Turbo Pascal, but in sport olympiads going to interrupts or assembler was prohibited. Not that it was going to help, but… when olympiads end, I was going those doors again, and others did not. For others my loved informatics was door remaining shut.
20 years later it is an excercize to find a device where loved EGA programming tricks work. Only unloved informatics remained
For those way to young to even know what this is, it's basically like MDN web documentation but for the DOS era. It was a community-maintained API reference for IBM PC hardware, DOS operating system, and other software.
This was, and for some purposes still is, one of the most useful documentation sets for the PC architecture. It's worth noting that Ralf himself isn't a specialist low-level programmer, as this came from an era when there was a far smaller divide between users, power users, and developers.
I remember looking at a print out of some of it in the late 80's and learning about the "list of lists", the critical section flag, and the alternate stack.
This was invaluable when I was tasked with writing a stay-resident boot loader just after the turn of the century. Even then, such information was considered arcane and Ralf Browns Interrupt List was much better than any official documentation I could find.
Endless hours spent exploring VGA hardware registers and trying to apply them for cool visual effects. Learning how the then-new 32-bit Windows interacted with DOS extenders, and trying to make a homemade - very basic - operating system that could do it, too. The thrill of writing a Terminate and Stay Resident alarm clock, and having it finally not explode...
I have very fond memories of the Ralf Brown's Interrupt List.
I think that has been one of the very first and largest information collection shared for free on the internet.
Kudos to Ralf Brown and whoever participated in keeping the list compete, accurate and timely.
20 years later it is an excercize to find a device where loved EGA programming tricks work. Only unloved informatics remained
https://www.ctyme.com/rbrown.htm