ZX81 Listing for z80digrain.p

Z80 DIGITAL RAIN * SLR/2021 (z80digrain.p)

I decided to revisit my Digital Rain program, but using z80 assembler. This version includes support for Chroma as well as a stock ZX81.

SYSTEM VARIABLES

PROG  : 16509
D-FILE: 17045
VARS  : 17838
E-LINE: 17839
STKBOT: 17844
STKEND: 17844

LEGEND

9999 means line number
PRINT means treat as KEYWORD P

PROGRAM LISTING

   1 REM /Q (C) 2021 STEVEN REID
            + Z80 DIGITAL RAIN +
52523 ?PIY4LN PPIX5Y!FOR LN PPI
FOR ñ4 ù?ùQ 51INKEY$ö4?M?INKEY$6
?INKEY$?PIE?INKEY$TAB ?INKEY$Y?
LN PPIRETURN M AND HINKEY$Y/LN P
PI?U?INKEY$??LN CONT INKEY$
THEN INKEY$?U?PINEW 4?ASN C
INKEY$LEN  ö$LN SAVE INKEY$E?
INKEY$U?INKEY$?LEN ;LN CONT
INKEY$Jö£LN .PI??INKEY$INKEY$ö?
LN SAVE INKEY$E?INKEY$U?INKEY$?O
QNEW FõTAB SCROLL RNDLN ?PILN Vò
?=ASN ""RNDLN ?PI?>=£           
                                
                                
                         FOR YP
LN PPILEN úFOR TAN E£RND?- ;25?õ
COS ;(CLEAR TAN ?U?PINEW 4""ACS
UNPLOT ?ACS W?RETURN ?"") TO
COPY ;FAST BGOSUB ?£RNDGOSUB ?
LPRINT **ACS UNPLOT Q£TAN ?U?PI
NEW 4""GOSUB ?£RND5RUN ò;U?
INKEY$?- ;ACS UNPLOT ?TAN ñ  
PRINT EORNDùF?NEW ??6QPILET ?)4 
; TAN ñ?ò" ?L4IF TAN COPY ñLOAD
?GOSUB ?M?PINEW 4""YSGOSUB ?TAN
ñLOAD ?GOSUB ?NEW 4""JGOSUB ?Y
COPY M?PITAN
   2 RAND USR VAL "16514"