OS/2 Graphics Functions May Fail on 8514/A Display Adapter

ID Number: Q67005

6.00 6.00a

OS/2

buglist6.00 fixlist6.00a

Summary:

The graphics functions in GRTEXTP.OBJ provided for OS/2 in Microsoft C

version 6.00 do not properly recognize the 8514/A display adapter when

setting video modes. This results in the inability to set the number

of text rows to certain values.

If the 8514/A display is set to 50-line mode, an attempt to use

_settextrows() to set the number of rows to 43 will fail. If the

screen is set to 25- or 43-line mode, the call to _settextrows() will

succeed, but the screen may only be in 25-line mode.

More Information:

To view this problem, use the SORTDEMO program supplied as an example

with the C 6.00 package. This program tries to put the screen in

43-line mode.

Compile SORTDEMO.C for OS/2 as described in the comments at the top of

the file. Type MODE CO80,50 at the OS/2 command-prompt to put the

screen in 50-line mode, then run the program. The program will cause a

general protection violation (GP fault). If you type MODE CO80,25, the

program will run but it will only detect CGA equivalent video, and

therefore, will only run in 25-line mode.

Microsoft has confirmed this to be a problem in C version 6.00. This

problem has been corrected in C version 6.00a.