BEGIN
   BOOL g keep going := TRUE, g fis number entering := FALSE;
   STRING g display str := "";
   LONG REAL g ax := 0.0, g bx := 0.0;
   INT g binop := -1;

   []STRING kbd str = ("Off"," C ","<x)"," * "," 7 "," 8 "," 9 "," / "," 4 "," 5 "," 6 "," + "," 1 "," 2 "," 3 "," - "," 0 "," . ","+/-"," = ");
   []STRING kbd clr = ("02628095","02628095","02628095","01015567","00986895","00986895","00986895","01015567","00986895","00986895","00986895","01015567","00986895","00986895","00986895","01015567","00986895","00986895","00986895","01015567");

   PROC flush = VOID: (make term(stand out, ""));
   PROC rgb = (INT r, g, b) INT: (r * 65536) + (g * 256) + b;
   PROC s = (INT val) STRING: " " + whole(val, 0);
   PROC pl = (STRING msg) VOID: (print((msg, newline)));

   PROC ds = (INT f, STRING psz, INT clr) VOID: (
     pl("F " + whole(f, 0) + " 16777215");
     pl("FR " + whole(f, 0) + s(0) + s(0) + s(9900) + s(600));
     pl("F " + whole(f, 0) + " " + whole(clr, 0));
     pl("R " + whole(f, 0) + s(100) + s(100) + s(9800) + s(500));
     pl("R$ " + whole(f, 0) + s(9800) + s(520) + """" + psz + """");
     pl("Z "); flush
   );

   PROC key to exe = (INT rc) VOID: (
     FILE f_handle;
     CASE rc + 1 IN
       (pl("O 0 0 0"); flush; g keep going := FALSE),
       (g display str := ""; ds(0, "0", rgb(92,92,127)); g fis number entering := FALSE),
       (IF UPB g display str > 0 THEN 
           g display str := g display str[1 : UPB g display str - 1];
          ds(0, (UPB g display str = 0 | "0" | g display str), rgb(92,92,127))
        FI)
     OUT
       IF rc = 3 OR rc = 7 OR rc = 11 OR rc = 15 THEN
         g binop := rc; 
         IF UPB g display str > 0 THEN associate(f_handle, g display str); get(f_handle, g ax); close(f_handle) FI;
         g fis number entering := FALSE
       ELIF rc = 19 THEN
        IF g fis number entering THEN 
          IF UPB g display str > 0 THEN associate(f_handle, g display str); get(f_handle, g bx); close(f_handle) FI;
          g fis number entering := FALSE 
        FI;

        # Safety Check for Division by Zero #
        IF g binop = 7 AND g bx = 0.0 THEN
          g ax := 9.99999999999999e99
        ELSE
          IF g binop = 3 THEN g ax *:= g bx ELIF g binop = 7 THEN g ax /:= g bx
          ELIF g binop = 11 THEN g ax +:= g bx ELIF g binop = 15 THEN g ax -:= g bx FI
        FI;
        
        LONG REAL abs ax = (g ax < 0 | -g ax | g ax);
        STRING res;
        IF abs ax = 0 THEN 
          res := "0"
        ELIF abs ax >= 1e15 OR abs ax <= 1e-4 THEN
          res := float(g ax, -24, 14, 2)
        ELSE
          res := fixed(g ax, -24, 14)
        FI;
        
        INT first := 1; WHILE (first < UPB res AND (res[first] = " ")) DO first +:= 1 OD;
        STRING trimmed := res[first:];
        
        INT dot pos, e pos;
        IF char in string(".", dot pos, trimmed) THEN
           IF NOT char in string("e", e pos, trimmed) THEN
              INT last := UPB trimmed;
              WHILE (last > 1 AND (trimmed[last] = "0")) DO last -:= 1 OD;
              IF trimmed[last] = "." THEN last -:= 1 FI;
              trimmed := trimmed[1:last]
           FI
        FI;
        
        g display str := trimmed;
        ds(0, g display str, rgb(92,92,127))
       ELSE
         STRING raw = kbd str[rc+1];
         STRING ch := "";
         FOR i TO UPB raw DO IF raw[i] /= " " THEN ch +:= raw[i] FI OD;
         IF NOT g fis number entering THEN g display str := ch; g fis number entering := TRUE
         ELIF UPB g display str < 23 THEN g display str +:= ch FI;
         ds(0, g display str, rgb(92,92,127))
       FI
     ESAC
   );

   PROC draw app = VOID: (
     pl("Fo 0 611 3"); pl("Fo 2 140 3"); pl("F 0 16777215");
     pl("FR 0" + s(0) + s(0) + s(10000) + s(10000));
     pl("F 0 12632256");
     FOR rc FROM 0 TO 19 DO pl("FR 0" + s((rc MOD 4)*2000+190) + s((rc OVER 4)*1200+1190) + s(((rc MOD 4)+1)*2000+110) + s(((rc OVER 4)+1)*1200+1110)) OD;
     pl("F 0 986895");
     FOR rc FROM 0 TO 19 DO pl("R 0" + s((rc MOD 4)*2000+200) + s((rc OVER 4)*1200+1200) + s(((rc MOD 4)+1)*2000+100) + s(((rc OVER 4)+1)*1200+1100)) OD;
     pl("B 0 12632256");
     []STRING lyr = ("00986895", "02628095", "01015567");
     FOR i TO 3 DO 
        pl("F 0 " + lyr[i]);
       FOR rc FROM 0 TO 19 DO 
          IF kbd clr[rc+1] = lyr[i] THEN pl("C$ 0" + s((rc MOD 4)*2000+1100) + s((rc OVER 4)*1200+1700) + """" + kbd str[rc+1] + """") FI
        OD
     OD;
     pl("F 0 255"); pl("C$ 0 5000 800""Algol cloud app""");
     pl("F 2 255"); pl("C$ 2 5000 7200""Corrie Zucker Technologies LLC.""");
     pl("C$ 2 5000 7340""d/b/a CZ Technologies""");
     pl("Z ");
     ds(0, (UPB g display str = 0 | "0" | g display str), rgb(92, 92, 127))
   );

   on logical file end (stand in, (REF FILE f) BOOL: (g keep going := FALSE; TRUE));

   WHILE g keep going DO
     STRING buf; 
     IF NOT (read((buf, newline)); TRUE) THEN g keep going := FALSE ELSE
       IF buf = "drawapp" THEN draw app
       ELIF buf = "QUERY_REMOTE" THEN pl("Rz 1200 900"); flush
       ELSE
         FILE input_s; INT b, x, y; 
         associate(input_s, buf); get(input_s, (b, x, y)); close(input_s);
         IF x >= 0 AND b = 1 THEN
           INT row := (y - 1200) OVER 1200, col := (x - 200) OVER 2000;
           IF row >= 0 AND row < 5 AND col >= 0 AND col < 4 THEN key to exe(row * 4 + col) FI
         ELIF x = -2 THEN
           CASE b IN SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, key to exe(2), SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, SKIP, key to exe(3), key to exe(11), SKIP, key to exe(15), key to exe(17), key to exe(7), key to exe(16), key to exe(12), key to exe(13), key to exe(14), key to exe(8), key to exe(9), key to exe(10), key to exe(4), key to exe(5), key to exe(6), SKIP, SKIP, SKIP, key to exe(19), SKIP, SKIP, SKIP, SKIP, SKIP, key to exe(1)
           OUT IF b = 79 OR b = 111 THEN key to exe(0) ELIF b = 73 OR b = 105 THEN key to exe(18) FI ESAC
         ELIF x = -4 THEN
           pl("Rz "+whole(b,0)+" "+whole(y,0))
         ELIF x = -5 THEN
           pl("Mv "+whole(b,0)+" "+whole(y,0))
       ELIF buf = "QUERY_REMOTE" THEN pl("Rz 1200 900"); flush
         FI
       FI
     FI
   OD
END