PA-RISC is a little weirder than the article lets on. The stack and heap are reversed - heap starts high and grows lows, while the stack starts low and grows up. This probably prevents a lot of casual buffer overflows.
It also has a 4-bit segment register. It's not the ugly overlapping segmentation of the x86, more like a register that selects completely different, non-overlapping, address spaces.
(author) Thanks! Yes, HP-UX does do that with the stack and heap, but I don't believe this was obligatory to PA-RISC; that's just how the calling convention was defined.
Interesting that it's running NeXTSTEP. We had not this but a different PA-RISC machine in the office where I worked running HP-UX.
If you click/open image in new tab/click again to zoom, you'll find it's much higher resolution than the in-page view. There's even a BeOS box in the top-right.
I should have taken the PA-RISC machine that was offered to me a few years back. It was also an old Navy machine, and had the entire SAN with it. It was one of the big towers, a 120MHz if I recall correctly, dual socket. A J200 or J210 I think. I was told it was an old setup for a flight simulator (this was at a training command).
I didn't have space or a use for it, but as far as I know it's still sitting in that closet. It had been there for 10+ years and no-one was moving it.
I owned a J210XC for a while. It was not dual socket despite the huge and heavy case. It ran 32-bit 120Mhz. Mine had 1GB of memory though which was amazingly huge at the time (a PC would come with 128MB perhaps)
Eventually I got rid of it because it was just such a huge ass box... I regret it a bit. I do have a small pizza box though.
PA-RISC is a little weirder than the article lets on. The stack and heap are reversed - heap starts high and grows lows, while the stack starts low and grows up. This probably prevents a lot of casual buffer overflows.
It also has a 4-bit segment register. It's not the ugly overlapping segmentation of the x86, more like a register that selects completely different, non-overlapping, address spaces.