ZX81 Listing for prtscrl.p

**PRTSCRL**SLR/2024** (prtscrl.p)

A ZX81 alternative PRINT function that scrolls when at the bottom of the display. The intent is to show how to call machine language functions from BASIC and passing parameters on the same line. https://youtu.be/tQwA9HgaTJM

SYSTEM VARIABLES

PROG  : 16509
D-FILE: 16786
VARS  : 16811
E-LINE: 16812
STKBOT: 16817
STKEND: 16817

LEGEND

9999 means line number
PRINT means treat as KEYWORD P

PROGRAM LISTING

   1 REM **PRTSCRL**SLR/2024**
   2 REM SCROLL LN EXIT ?LN
SAVE <LN DRNDINT COPY ,NOT LN P
RND<"?L4PRINT TAN STR$ VAL ñPòE£
RNDùFOR E:RNDJGOSUB DELETE ?P
ATN LN RNDAT SGN TAN E£RND7LOOP
DATA ñ5 ùñPòGOSUB Kñ+òE£RNDù6:
RNDTAN
  10 DIM S$(3,6)
  20 LET S$(1)="HELLO/"
  30 LET S$(2)="LATER."
  40 LET S$(3)="ALOHA*"
  50 CLS
  60 PRINT USR 16541;S$(INT (RND
*3)+1)+" "
  70 GOTO 60