INT 2F - European MSDOS 4.0 POPUP - "PostPu" - OPEN/CLOSE POPUP SCREEN
AX = 1401h
DL = function (00h open, 01h close)
DH = wait flag
00h block until screen opens
01h return error if screen is not available
02h urgent--always open screen immediately
Return: CF clear if successful
BX = amount of memory needed to save screen and keyboard info,
0000h if default save location can be used (only if DH was 02h)
CF set on error
Note:   the application using the screen is frozen until the popup screen is
closed
SeeAlso: AX=1402h"POPUP",AX=1403h"POPUP"

See also: 2F1400

2F1401 - European MSDOS 4.0 POPUP - "PostPu" - OPEN/CLOSE POPUP SCREEN