FIX: Compiled QuickBasic Sys Error on Macintosh IIci IIcx IIfx (59137)

SYMPTOMS

Programs compiled with the Use Default Window option in Microsoft QuickBasic version 1.00 can fail at run time with a System error (bomb) ID=1 on the Macintosh IIci, IIcx, and IIfx. The same compiled program runs correctly on other Macintoshes, including the Macintosh Plus, SE, or II. The same program runs correctly in QuickBasic's interpreter on all of the above Macintoshes.

Microsoft has confirmed this to be a bug in programs compiled in Microsoft QuickBasic version 1.00 for the Macintosh . This problem was corrected in QuickBasic version 1.00a, which was released specifically to correct this problem (and no other problems). Later, QuickBasic version 1.00b was released, which also corrects this problem (in addition to correcting other problems). Microsoft recommends upgrading to the latest release for QuickBasic, version 1.00b (as of April 1991).

Version 1.00a was needed only by programmers developing compiled programs to run on the Macintosh IIci, IIcx, and IIfx, since no other problems were corrected by 1.00a.

You can work around this problem in QuickBasic 1.00 by NOT compiling with Use Default Window from the Options dialog box (under the Run menu), and using a WINDOW statement to make your own output window.

MORE INFORMATION

The Macintosh IIci, IIcx, and IIfx computers were released by Apple after Microsoft released QuickBasic 1.00. Microsoft released QuickBasic 1.00a to correct the introduced incompatibility.

To duplicate the problem, compile the following program in QuickBasic 1.00 with the Use Default Window option and run the compiled " apl" program on a Macintosh IIci, IIcx, or IIfx computer:

   PRINT "Hello world"

To work around the problem in 1.00, compile without the Use Default Window option and add a WINDOW statement, such as the following:

   WINDOW 1,"TEST",(2,40)-(400,300)
   PRINT "Hello world"

We have found that this compatibility problem may be related to the memory configuration and the number of empty memory slots on the Macintosh IIci. The Macintosh IIci computers that demonstrate this problem have had 4 megabytes of RAM (four 1-megabyte SIMS), leaving four empty memory slots. When these four empty memory slots are filled (for example, by expanding to 5 megabytes using four 256K SIMS), the problem disappears.