Tell me more ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.
up vote 2 down vote favorite
1

I plan to write a fairly decent OS in 16-bit real mode only to stick with 16-bit registers and the mode supports all I/O read and writes, but the memory is not enough.

What are the basic steps to exceed this? Anything will help, so thanks in advance.

share|improve this question
If you need help with segmented addresses, are you really ready to build a "fairly decent OS"? – Nicole Hamilton Dec 26 '12 at 21:33
1  
Check the OSDeve Wiki for lots of details. – David Schwartz Dec 26 '12 at 21:33
What language will you be using, assembler? (Mmmm… assembler.)     If this is a school thing, I suggest checking the textbook and notes because they should contain whatever information you need to accomplish your goal. – Synetech Dec 26 '12 at 21:48
Check out CP/M and learn how 64 kB could be enough. From there step to a 16 bit OS. – ott-- Dec 26 '12 at 21:57
Since you're reinventing the wheel, read up on EMS memory. There's links in the article to similar things, like XMS memory. – martineau Dec 27 '12 at 3:33

closed as not constructive by Nicole Hamilton, Dave M, Synetech, TFM, techie007 Dec 27 '12 at 3:11

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or specific expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, see the FAQ for guidance.

1 Answer

up vote 3 down vote

Use Protected Mode. No, really. Implement a TSR that will shuffle pages between the first megabyte and upper memory, switching to Protected Mode in order to access it and then back to Real Mode when done.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.