25 Feb
2006
25 Feb
'06
10:50 a.m.
On 2/25/2006 at 9:34 AM Eric J Korpela wrote:
OS/2 1.X definitely does segment swapping with support
for logically
adjacent segments, as do some 286 DOS extenders. The selector math
isn't that difficult (to get the next segment you add 8).
...and Windows also allowed this for large memory allocations, though it
was held in the realm of "undocumented". I know of no 286 OS that used
sequentially-numbered selectors to divide up the whole memory space into
uniform 64K segments, a la "real" paging. IOW, you couldn't simply take
any arbitrary address and compute the selector for a new address from it
without knowing the value of the selector for some other address.
Cheers,
Chuck