en:docs:dpmi:api:int31:06:04

Note: This API calls are shared between DOS and Win16 personality.

DPMI is a shared interface for DOS applications to access Intel 80286+ CPUs services. DOS DMPI host provides core services for protected mode applications. Multitasking OS with DOS support also provides DMPI in most cases. Windows standard and extended mode kernel is a DPMI client app. Standard and extended mode kernel differs minimally and shares common codebase. Standard Windows kernel works under DOSX extender. DOSX is a specialized version of 16-bit DPMI Extender (but it is standard DPMI host). Standard mode is just DPMI client, exnhanced mode is DPMI client running under Virtual Machime Manager (really, multitasker which allow to run many DOS sessions). Both modes shares DPMI interface for kernel communication. The OS/2 virtual DOS Protected Mode Interface (VDPMI) device driver provides Version 0.9 DPMI support for virtual DOS machines. Win16 (up to Windows ME) provides Version 0.9 DPMI support. Windows in Standard Mode provides DPMI services only for Windows Applications, not DOS sessions.

DPMI host often merged with DPMI extender. Usually DPMI extender provide DPMI host standard services and DOS translation or True DPMI services.

2021/08/05 10:15 · prokushev · 0 Comments

Int 31H, AH=06H, AL=04H

Version

0.9

Brief

Get Page Size

Input

AX = 0604H
  

Return

if function successful
Carry flag = clear
BX:CX = page size in bytes

if function unsuccessful
Carry flag = set
AX = error code
8001H	unsupported function (16-bit host)

Notes

Returns the size of a single memory page in bytes.

See also

Note

DPMI
Process manager INT 2FH 1680H, 1687H
Signals
Memory manager
Misc INT 2FH 1686H, 168AH
Devices
2021/08/13 14:23 · prokushev · 0 Comments