ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º Warning! STAT applications can wipe memory! º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ äDAT EDIT bug, G/GX, rev K-P. Reported by EduCALC customer to Richard Nelson. HP, when asked, said they knew about it. This writeup is by Joe Horn. ÚÄÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³ DESCRIPTION ³ On an HP 48G or GX, version K through P, press: ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÙ left-shift 5 (shows stat menu) DATA (the first softkey) 3 left-shift äDAT (stores the 3 into äDAT) right-shift 5 (shows the STAT application choose box) ENTER (starts the Single-Var Statistics application) EDIT (either the softkey or on the keyboard) ÄÄ Memory Clear ÚÄÄÄÄÄÄÄ¿ ³ CAUSE ³ The EDIT key in the STAT applications throws the contents of ÀÄÄÄÄÄÄÄÙ äDAT into the MatrixWriter without first performing an object type check. This is reasonable, since the creation of äDAT from the applications *does* perform object type checking. They forgot that äDAT can be created elsewhere first, however. When an object that is not an array (matrix) is thrown into the MatrixWriter, which only knows how to work with arrays, all hell breaks loose. Wanna see your HP48 on drugs? Perform the routine described above, but instead of 3, use { 0 }. The MatrixWriter will launch, but filled with garbage values. Press right-shift down-arrow, then right-shift right-arrow. Look at the cell coordinates on the command line! It would appear that we are editing a complex matrix that's 979,058 by 480,114! Yikes; that would require 7.52 Terabytes of RAM! Pressing ON twice to exit reveals a pile of junk on the stack. Bad news. ÚÄÄÄÄÄÄÄÄÄÄÄÄ¿ ³ WORKAROUND ³ The best workaround is never to store non-arrays into ÀÄÄÄÄÄÄÄÄÄÄÄÄÙ äDAT, which is a silly thing to do anyway. But since software might do so, a sufficient workaround is to visually inspect äDAT before pressing EDIT, and if it's not an array, then press MATRIX (right-shift ENTER) instead of EDIT, or simply to type the matrix directly from the keyboard and press ENTER.