[HN Gopher] DOS/4GW and Protected Mode (2021) ___________________________________________________________________ DOS/4GW and Protected Mode (2021) Author : atan2 Score : 19 points Date : 2022-11-20 21:19 UTC (1 hours ago) (HTM) web link (pikuma.com) (TXT) w3m dump (pikuma.com) | dusted wrote: | So cool to finally read about this.. I remember wondering about | this when I was a kid, starting games.. | hericium wrote: | And nowhere to search for info on it! | lizknope wrote: | I first learned C in 1991 on a VAX running VMS and also on an IBM | AIX machine. If I went outside the array bounds I might get a | crash or segfault and could use a debugger to load the crash dump | and see where it died. | | When I tried using my roommate's DOS PC and C compiler I crashed | the entire machine so many times. There was no memory protection | of any kind. Write something outside the array bounds and you | could overwrite critical DOS data structures and lock up the | whole machine. Hard reboot so many times. | | Then my roommate tried to explain near and far pointers. I never | understood it until I looked it up a few years ago. It was all | related to the 16-bit vs 32-bit segmented vs flat memory models. | Everything just seemed so much easier and faster on the VMS and | Unix systems. But the also cost 10 to 100 times as much. | | I also thought it was really pathetic that I could only run one | program at a time. On the VAX and Unix systems 10 to 200 people | could be logged on at the same time all doing there own thing and | it was very difficult to accidentally bring down the whole | machine. | | It all made me NOT want my own PC because DOS/Win 3.1 was so | limited. It wasn't until Linux in 1993 that I wanted my own PC. | JayGuerette wrote: | "... a terminate-and-stay-resident program (or TSR) was a | computer program running under DOS that uses a system call to | return control to DOS as though it has finished, but remains in | computer memory so it can be reactivated later. Needless to say, | this was extremely unreliable." | | There were very likely some hacky TSRs that caused problems, but | in my experience most were extremely reliable. We used an off- | the-shelf TSR to enhance a motion control system that laser | scribed ceramic vacuum checks for silicon wafer fabrication. | Those things cost $5k in 1990, and took ~20h of processing, | increasing their value to $15k; we wouldn't screw around with | something that was inherently "extremely unreliable". | jmclnx wrote: | Very interesting article. My objects were always written for real | mode on DOS, by the time I would have wanted to use these | extenders, Coherent and then Linux came out. | forgotmypw17 wrote: | https://archive.ph/SpUm4 ___________________________________________________________________ (page generated 2022-11-20 23:00 UTC)