Tyd-Bits

Poking MODE

The 2068 User Manual indicates that the system variable MODE, at address 23617, specifies the cursor (K, L, C, G, or E), and that “Poking the variable will have no lasting effect.” This is not entirely correct.

First, the contents of MODE are determined as follows:

    CONTENTS   BIT SET   CURSOR (S)
      0         NONE     K, L or C
      1          0        E
      2          1        G

If the system variable MODE is zero, then the cursor or (L or C) is determined by the contents of the variable FLAGS2, at the address 23658. 0 (no bit set) will give the L cursor and 8 (bit 3 set) will give a C cursor.

POKEing the desired value into MODE will give the desired effect long enough to provide a preselected cursor in a following INPUT statement. This permits, for example, the following BASIC code:

  10 BORDER 0: INK 6: PAPER 0: CLS
  20 INPUT "Location-  Vert: ";v;';"     Horiz: ";h
  30 INPUT "Paper: ";p;';"Ink: ";i
  40 POKE 23617,2
  50 INPUT "Graphic: ";g$
  60 POKE 23617,0
  70 PRINT AT v,h; PAPER p; INK i;g$
  75 PAUSE 200
  80 GO TO 10