Timeline for How can I access/use memory outside of the standard 1 MB address range of MS-DOS?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 24, 2020 at 17:08 | history | edited | Jim Nelson | CC BY-SA 4.0 | expand answer with note about moving memory |
| S Mar 22, 2020 at 20:31 | history | suggested | Peter Mortensen | CC BY-SA 4.0 | Expanded, etc. |
| Mar 22, 2020 at 19:54 | review | Suggested edits | |||
| S Mar 22, 2020 at 20:31 | |||||
| Mar 22, 2020 at 12:09 | comment | added | ecm | XMS extended memory doesn't have to be locked to use it. Indeed some XMMs do not even allow locking extended memory blocks. The idiomatic way of accessing XMS extended memory is by filling an XMS memory move structure to transfer data between 86-Mode memory and an extended memory block, or between two extended memory blocks. Locking is only useful to a. access memory in protected mode or b. use it for device DMA or such. | |
| Mar 22, 2020 at 10:42 | vote | accept | DarkAtom | ||
| Mar 21, 2020 at 21:06 | history | edited | Jim Nelson | CC BY-SA 4.0 | Not a good use of "frees" here |
| Mar 21, 2020 at 20:54 | history | edited | Jim Nelson | CC BY-SA 4.0 | Answer last two questions |
| Mar 21, 2020 at 20:44 | comment | added | John Dallman | To add to this, the lock/unlock design pattern means that you must forget any pointers to anything in XMS memory when you unlock it. Failing to do so was a common programming problem on 16-bit Windows, and Classic Mac OS, which are quite similar in this respect. 32-bit Windows and Mac OS X both abandoned that idea as far more trouble than it was worth, given a larger address space. | |
| Mar 21, 2020 at 20:28 | history | edited | Jim Nelson | CC BY-SA 4.0 | Added explanation |
| Mar 21, 2020 at 20:21 | history | edited | Jim Nelson | CC BY-SA 4.0 | Correction |
| Mar 21, 2020 at 20:15 | history | answered | Jim Nelson | CC BY-SA 4.0 |