Technical Reference Guide
Compaq Deskpro Personal Computers
Third Edition - April 2001
8-15
8.5.3 TEMPERATURE STATUS
The BIOS includes a function (INT15, AX=E816h) to retrieve the status of a system’s interior
temperature. This function allows an application to check whether the temperature situation is at a
Normal, Caution, or Critical condition.
8.5.4 DRIVE FAULT PREDICTION
The Compaq BIOS directly supports Drive Fault Prediction for IDE-type hard drives. This feature
is provided through two Client Management BIOS calls. Function INT 15, AX=E817h is used to
retrieve a 512-byte block of drive attribute data while the INT 15, AX=E81Bh is used to retrieve
the drive’s warranty threshold data. If data is returned indicating possible failure then the
following message is displayed:
“1720-SMART Hard Drive detects imminent failure”
8.6 PNP SUPPORT
The BIOS includes Plug ’n Play (PnP) support for PnP version 1.0A. Table 8-5 lists the PnP
functions supported.
Table 8-5. PnP BIOS Functions
Table 8-5. 
PnP BIOS Functions 
Function Register 
00h  Get number of system device nodes 
01h  Get system device node 
02h  Set system device node 
03h Get event 
04h Send message 
50h  Get SMBIOS Structure Information 
51h  Get Specific SMBIOS Structure 
The BIOS call INT 15, AX=E841h, BH=01h can be used by an application to retrieve the default
settings of PnP devices for the user. The application should use the following steps for the display
function:
1. Call PnP function 01(get System Device Node) for each devnode with bit 1 of the control flag
set (get static configuration) and save the results.
2. Call INT 15, AX=E841h, BH=01h.
3. Call PnP “Get Static Configuration” for each devnode and display the defaults.
4. If the user chooses to save the configuration, no further action is required. The system board
devices will be configured at the next boot. If the user wants to abandon the changes, then the
application must call PnP function 02 (Set System Device Node) for each devnode (with bit 1
of the control flag set for static configuration) with the results from the calls made prior to
invoking this function.