Added some system constants

.idea/.gitignore

@@ -0,0 +1,3 @@
+# Default ignored files
+/shelf/
+/workspace.xml

.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/classes" />
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

more.merlin.s

@@ -85,8 +85,12 @@ KBD             EQU     $C000       ;KEYBOARD DATA AND STROBE
 CXROMOFF        EQU     $C006       ;SELECT SLOT ROMS
 CXROMON         EQU     $C007       ;SELECT INTERNAL ROM
 KBDSTRB         EQU     $C010       ;CLEAR KEYBOARD STROBE
+MIXED           EQU     $C01B       ;R7=1 MIXED, R7=0 FULL GR
+PAGE2           EQU     $C01C       ;R7-1 PAGE ACTIVE (OR AUX)
 ALTCHAR         EQU     $C01E       ;CHARACTER SET STATUS
 RD80VID         EQU     $C01F       ;<=128->40COL, >128->80COL
+PAGE2OFF        EQU     $C054       ;SEL PG1 (RW)
+PAGE2ON         EQU     $C055       ;SEL PG2 (RW)
 INVERT          EQU     $CEDD       ;INVERT CHARACTER ON SCREEN
 PICK            EQU     $CF01       ;PICK CHARACTER OFF SCREEN
 *
@@ -108,6 +112,10 @@ CLOSEPARMCNT    EQU     1
 *
 CR_CHAR         EQU     $0D         ;ASCII CARRIAGE RETURN
 CR_HIBIT        EQU     $8D         ;CARRIAGE RET WITH HIGH BIT SET
+RIGHT_ARROW     EQU     $15
+RIGHT_HIBIT     EQU     $95
+LEFT_ARROW      EQU     $08
+LEFT_HIBIT      EQU     $88
 *
 * CONSTANTS
 *
@@ -353,7 +361,7 @@ MAIN           CLD                  ;CLEAR DECIMAL FLG, AVOID CRASH
 GET_SCRN_WDTH   LDA     #%10000000      ;USE ALTCHARSET STATUS TO
                 BIT     ALTCHAR         ;SEE IF 80-COL CARD TURNED ON
                 BMI     :CARD_ACTIVE    ;BIT 7 ON = NEG & CARD ACTIVE
-                JMP     :FORTY_COLUMNS  ;INACTIVE CARD IS 40-COL
+                JMP     :FORTY_COLUMNS  ;INACTIVE = DEFLT 40-COL MODE
 :CARD_ACTIVE    LDA     #%10000000      ;SEE IF CARD IS IN 40/80 MODE
                 BIT     RD80VID         ;BIT 7 OFF = 0 OR >0 & 40-COL
                 BMI     :EIGHTY_COLUMNS ;BIT 7 ON = NEG & 80-COL MODE
@@ -608,6 +616,15 @@ DOWN1LINE   INC     SCRNLINE    ;KEEP TRACK OF LINE NUMBER
             JSR     CROUT       ;LINE DOWN & SCROLL IF NEEDED
             RTS
 
+********************************
+*                              *
+* WRITE CHAR TO PAGE2          *
+* CLIPS TO SCREEN WIDTH        *
+*                              *
+********************************
+WRITECHAR2
+            RTS
+
 ********************************
 *                              *
 * PRINT ASCII IN HEX           *
@@ -631,8 +648,7 @@ PRASCII        PHA
 *                              *
 ********************************
 
-STATBAR
-               DO    TRACE
+STATBAR     DO      TRACE
             PUTS    ENSTATB
             FIN
 
@@ -645,12 +661,15 @@ STATBAR
             JMP     :ENDLOOP        ;PROCESSED SPACE SO DONE
 :CHKCR      CMP     #CR_HIBIT       ;CHECK FOR CARRIAGE RETURN
             BNE     :CHKQUIT
-               SET23 SCRNLINE
+            COPY_B  SCRNLINE;#23
             JMP     :ENDLOOP
 :CHKQUIT    CMP     #"Q"            ;USER WANTS TO QUIT
             BEQ     :QUITTING       ;NO RECOGNIZED INPUT
             CMP     #"q"
             BEQ     :QUITTING
+            CMP     RIGHT_HIBIT
+            BNE     :ENDLOOP
+            JSR     PAGE_RIGHT
             JMP     :LOOP
 :QUITTING   SET1    USRQUIT
 :ENDLOOP    JSR     ERASEBAR
@@ -674,7 +693,8 @@ ERASEBAR
                FIN
 
                PUSHY
-               SET0  OURCH      ;RESET CURSOR TO BEG OF LINE
+               COPY_B   OURCH;#0    ;CURSOR TO BEG OF LINE, 80-COL
+               COPY_B   CH;#0       ;CURSOR TO BEG OF LINE, 40-COL
                LDY      #0          ;INIT COUNTER FOR SPACES
 :LOOP          CPY      BAR         ;FIRST BYTE IS LENGTH
                BEQ      :ENDLOOP    ;IF Y=LEN THEN DONE
@@ -682,7 +702,8 @@ ERASEBAR
                JSR      COUT        ;WRITE TO SCREEN
                INY                  ;MAKE PROGRESS
                JMP      :LOOP       ;LOOP TO NEXT CHAR
-:ENDLOOP       SET0  OURCH      ;RESET CURSOR TO BEG OF LINE
+:ENDLOOP       COPY_B   OURCH;#0    ;RESET CURSOR TO BEG OF LINE
+               COPY_B   CH;#0       ;CURSOR TO BEG OF LINE, 40-COL
                POPY
 
                DO       TRACE
@@ -691,6 +712,14 @@ ERASEBAR
 
                RTS
 
+********************************
+*                              *
+* PAGE 2 ON                    *
+*                              *
+********************************
+PAGE_RIGHT  STA     PAGE2ON
+            RTS
+
 ********************************
 *                              *
 * ERROR HANDLER                *
@@ -887,6 +916,7 @@ BUFCHAR        DS    1
 USRCHAR         DS      1
 SCR_WDTH        DS      1
 SCR_WDTH_TXT    STR     "SCREEN WIDTH="
+TEXTPAGE        DS      1
 
 PREFIXMSG       STR     "THE PREFIX IS "
 WARNING         STR     'WARNING'
@@ -965,7 +995,7 @@ CLOSFNUM       DS    1
 * BUFFERS
 *
 * CONSUME ALL BYTES UP TO THE NEXT PAGE BOUNDRY
-FILLER DS \,$00
+*FILLER DS \,$00
 * MUST START ON PAGE BOUNDRY
 *OPENBUF DS 1024
 *READBUF DS BUFSIZE