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Which operating systems for 80286 computers allowsed a process to use more than 128k data?
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Out of all operating systems for the 80286 processor I found, only two make use of the protected mode's ability to load more than one segment for text and one for data. These are MS DOS (through various DOS extenders) and Windows. All other operating systems I checked would only give one text segment and one data segment to each process and call it a day. Were there any other operating systems that made full use of protected mode segmentation on the 80286?
operating-system 80286 segmentation
asked 1 hour ago
fuz
447416
add a comment |Â
up vote
2
down vote
favorite
Out of all operating systems for the 80286 processor I found, only two make use of the protected mode's ability to load more than one segment for text and one for data. These are MS DOS (through various DOS extenders) and Windows. All other operating systems I checked would only give one text segment and one data segment to each process and call it a day. Were there any other operating systems that made full use of protected mode segmentation on the 80286?
operating-system 80286 segmentation
asked 1 hour ago
fuz
447416
I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
1
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by thechmemutility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even abrksyscall!
– fuz
56 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
1
What about Xenix 286?
– mannaggia
28 mins ago
add a comment |Â
up vote
2
down vote
favorite
up vote
2
down vote
favorite
Out of all operating systems for the 80286 processor I found, only two make use of the protected mode's ability to load more than one segment for text and one for data. These are MS DOS (through various DOS extenders) and Windows. All other operating systems I checked would only give one text segment and one data segment to each process and call it a day. Were there any other operating systems that made full use of protected mode segmentation on the 80286?
operating-system 80286 segmentation
asked 1 hour ago
fuz
447416
Out of all operating systems for the 80286 processor I found, only two make use of the protected mode's ability to load more than one segment for text and one for data. These are MS DOS (through various DOS extenders) and Windows. All other operating systems I checked would only give one text segment and one data segment to each process and call it a day. Were there any other operating systems that made full use of protected mode segmentation on the 80286?
operating-system 80286 segmentation
operating-system 80286 segmentation
asked 1 hour ago
fuz
447416
asked 1 hour ago
fuz
447416
asked 1 hour ago
fuz
447416
asked 1 hour ago
fuz
447416
asked 1 hour ago
fuz
447416
447416
I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
1
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by thechmemutility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even abrksyscall!
– fuz
56 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
1
What about Xenix 286?
– mannaggia
28 mins ago
add a comment |Â
I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
1
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by thechmemutility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even abrksyscall!
– fuz
56 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
1
What about Xenix 286?
– mannaggia
28 mins ago
I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
1
1
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by the
chmem utility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even a brk syscall!– fuz
56 mins ago
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by the
chmem utility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even a brk syscall!– fuz
56 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
1
1
What about Xenix 286?
– mannaggia
28 mins ago
What about Xenix 286?
– mannaggia
28 mins ago
add a comment |Â
1 Answer
1
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up vote
3
down vote
OS/2 supported “huge memory†on 286s. Using the DosAllocHuge function, programs could allocate more than 64KiB of memory, and would get a sequence of segment selectors which could be used to easily access all the allocated memory. The process is detailed in section 9.2.2 of Gordon Letwin’s Inside OS/2.
Xenix 286 also supported multiple text and data segments; processes with multiple segments were called “large model processes†(the same terminology as was used with C compilers under DOS). See Overview of the Xenix 286 Operating System.
FlexOS 286 (and perhaps Concurrent DOS 286) also allowed programs to allocate multiple segments. malloc could only allocate up to 64KiB at once, but programs could call it multiple times to allocate more than 64KiB in total in multiple segments.
I suspected Coherent 3 might have supported multiple segments, but it turns out that’s not the case, at least according to the Coherent 3.2 FAQ (question 7).
answered 42 mins ago
Stephen Kitt
32.3k4130150
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
OS/2 supported “huge memory†on 286s. Using the DosAllocHuge function, programs could allocate more than 64KiB of memory, and would get a sequence of segment selectors which could be used to easily access all the allocated memory. The process is detailed in section 9.2.2 of Gordon Letwin’s Inside OS/2.
Xenix 286 also supported multiple text and data segments; processes with multiple segments were called “large model processes†(the same terminology as was used with C compilers under DOS). See Overview of the Xenix 286 Operating System.
FlexOS 286 (and perhaps Concurrent DOS 286) also allowed programs to allocate multiple segments. malloc could only allocate up to 64KiB at once, but programs could call it multiple times to allocate more than 64KiB in total in multiple segments.
I suspected Coherent 3 might have supported multiple segments, but it turns out that’s not the case, at least according to the Coherent 3.2 FAQ (question 7).
answered 42 mins ago
Stephen Kitt
32.3k4130150
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
add a comment |Â
up vote
3
down vote
OS/2 supported “huge memory†on 286s. Using the DosAllocHuge function, programs could allocate more than 64KiB of memory, and would get a sequence of segment selectors which could be used to easily access all the allocated memory. The process is detailed in section 9.2.2 of Gordon Letwin’s Inside OS/2.
Xenix 286 also supported multiple text and data segments; processes with multiple segments were called “large model processes†(the same terminology as was used with C compilers under DOS). See Overview of the Xenix 286 Operating System.
FlexOS 286 (and perhaps Concurrent DOS 286) also allowed programs to allocate multiple segments. malloc could only allocate up to 64KiB at once, but programs could call it multiple times to allocate more than 64KiB in total in multiple segments.
I suspected Coherent 3 might have supported multiple segments, but it turns out that’s not the case, at least according to the Coherent 3.2 FAQ (question 7).
answered 42 mins ago
Stephen Kitt
32.3k4130150
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
add a comment |Â
up vote
3
down vote
up vote
3
down vote
OS/2 supported “huge memory†on 286s. Using the DosAllocHuge function, programs could allocate more than 64KiB of memory, and would get a sequence of segment selectors which could be used to easily access all the allocated memory. The process is detailed in section 9.2.2 of Gordon Letwin’s Inside OS/2.
Xenix 286 also supported multiple text and data segments; processes with multiple segments were called “large model processes†(the same terminology as was used with C compilers under DOS). See Overview of the Xenix 286 Operating System.
FlexOS 286 (and perhaps Concurrent DOS 286) also allowed programs to allocate multiple segments. malloc could only allocate up to 64KiB at once, but programs could call it multiple times to allocate more than 64KiB in total in multiple segments.
I suspected Coherent 3 might have supported multiple segments, but it turns out that’s not the case, at least according to the Coherent 3.2 FAQ (question 7).
answered 42 mins ago
Stephen Kitt
32.3k4130150
OS/2 supported “huge memory†on 286s. Using the DosAllocHuge function, programs could allocate more than 64KiB of memory, and would get a sequence of segment selectors which could be used to easily access all the allocated memory. The process is detailed in section 9.2.2 of Gordon Letwin’s Inside OS/2.
Xenix 286 also supported multiple text and data segments; processes with multiple segments were called “large model processes†(the same terminology as was used with C compilers under DOS). See Overview of the Xenix 286 Operating System.
FlexOS 286 (and perhaps Concurrent DOS 286) also allowed programs to allocate multiple segments. malloc could only allocate up to 64KiB at once, but programs could call it multiple times to allocate more than 64KiB in total in multiple segments.
I suspected Coherent 3 might have supported multiple segments, but it turns out that’s not the case, at least according to the Coherent 3.2 FAQ (question 7).
answered 42 mins ago
Stephen Kitt
32.3k4130150
edited 2 mins ago
answered 42 mins ago
Stephen Kitt
32.3k4130150
answered 42 mins ago
Stephen Kitt
32.3k4130150
answered 42 mins ago
Stephen Kitt
32.3k4130150
32.3k4130150
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
add a comment |Â
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
Oh yeah, I totally forgot about OS/2. Any others you know of?
– fuz
41 mins ago
add a comment |Â
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I can find a lot of sources that strongly imply that MINIX is an answer, but none that is a smoking gun. Certainly there is a whole-system limit of 16mb but confirmation of per-process limits so far eludes me. Maybe somebody else can help?
– Tommy
59 mins ago
1
@Tommy Minix is not the answer as far as I'm concerned. On Minix, each process has one text and one data/stack segment. Segment sizes are fixed at link time and can be changed by the
chmemutility to give programs more space. It's not possible to change segment sizes at runtime, there isn't even abrksyscall!– fuz
56 mins ago
you have definitively stomped on that suggestion. I'll wager there's at least one CP/M-86 program that just runs away with the environment and thereby is as valid an answer as DOS, but that also feels like a cheat. It'd be interesting to know what VisiOn does given that programs are interpreted, not natively compiled.
– Tommy
49 mins ago
1
What about Xenix 286?
– mannaggia
28 mins ago