Run HELLO automatically if present

Just like BASIC.SYSTEM will automatically run STARTUP if present,
INTBASIC.SYSTEM will now run HELLO if present (and an INT file),
if the invoker didn't specify another path.

* If a file named HELLO is present but not an INT file, INTBASIC will
  exit immediately back to the program selector. Hold down Open Apple
  or Solid Apple to drop to the > prompt instead.

* If a file name HELLO is present and an INT file, INTBASIC will run
  it, then exit back to the program selector when the program exits.
  Hold Open Apple or Solid Apple to drop to the > prompt instead.

* If a file named HELLO is not present, INTBASIC will show the >
  prompt.

Resolves #13

Author: inexorabletash

README.md

@@ -28,6 +28,8 @@ This is a version of Steve Wozniak's Integer BASIC for the Apple II, with a wrap
    * Pressing <kbd>Control</kbd>+<kbd>C</kbd> will usually exit a program as well.
    * Optionally, hold down <kbd>Open Apple</kbd> or <kbd>Solid Apple</kbd> when starting to allow exiting the program to remain at the `>` prompt.
 
+3. When invoked directly, if a `INT` file named `HELLO` is present, will be run automatically.
+
 > ⚠️ Note that while Integer BASIC programs do have the ability to execute commands from BASIC with `PRINT "<control-D>..."`, only the above commands are supported. Commands for operating on text files (`OPEN`, `READ`, etc) are not supported.
 
 ## Integer BASIC

intbasic.system.s

@@ -150,15 +150,33 @@ ZP_SAVE_LEN     =  $15
         PATHBUF := $280
         PATH2   := $2C0
 
+.define STARTUP_FILE_NAME "HELLO"
+
 ;;; ProDOS Interpreter Protocol
 ;;; ProDOS 8 Technical Reference Manual
 ;;; 5.1.5.1 - Starting System Programs
         .org $2000
         jmp     start
         .byte   $EE, $EE        ; Interpreter signature
         .byte   $41             ; path buffer length
-path:   .res    $41,0           ; path buffer
-
+path:   .byte   .strlen(STARTUP_FILE_NAME), STARTUP_FILE_NAME
+        .res    path+$41-*,0    ; path buffer
+
+;;; Just used to test if startup file exists
+gfi_startup:
+        .byte   $A      ; param_count (in)
+        .addr   PATHBUF ; pathname (in)
+        .byte   0       ; access (out)
+        .byte   0       ; file_type (out)
+        .word   0       ; aux_type (out)
+        .byte   0       ; storage_type (out)
+        .word   0       ; blocks_used (out)
+        .word   0       ; mod_date (out)
+        .word   0       ; mod_time (out)
+        .word   0       ; create_date (out)
+        .word   0       ; create_time (out)
+
+;;; Shown if startup file does not exist
 banner:
         ;;      "----------------------------------------"
         scrcode "              INTEGER BASIC"
@@ -169,20 +187,6 @@ banner:
 
 start:
 
-;;; --------------------------------------------------
-;;; Display banner
-
-        jsr     HOME
-        lda     path
-        bne     done_banner
-        ldx     #0
-:       lda     banner,x
-        beq     done_banner
-        jsr     COUT
-        inx
-        bne     :-              ; always
-done_banner:
-
 ;;; --------------------------------------------------
 ;;; Copy path somewhere safe
 
@@ -196,16 +200,6 @@ done_banner:
         dex
         bpl     :-
 
-        ;; Unless Open- or Solid-Apple is down, hook END/ERRMESS to QUIT
-        lda     BUTN0
-        ora     BUTN1
-        bmi     done_path
-
-        lda     #OPC_JMP_abs
-        LDXY    #reloc__QuitFromIntBASIC
-        sta     reloc + (intbasic__WARM   - BASIC_START)
-        STXY    reloc + (intbasic__WARM+1 - BASIC_START)
-
 done_path:
 
 ;;; --------------------------------------------------
@@ -228,6 +222,33 @@ done_path:
         MLI_CALL SET_PREFIX, prefix_params
 prefix_ok:
 
+;;; --------------------------------------------------
+;;; Display banner (if startup file not present)
+
+        MLI_CALL GET_FILE_INFO, gfi_startup
+        beq     skip_banner
+
+do_banner:
+        jsr     HOME
+        ldx     #0
+:       lda     banner,x
+        beq     done_banner
+        jsr     COUT
+        inx
+        bne     :-              ; always
+
+skip_banner:
+        ;; Unless Open- or Solid-Apple is down, hook END/ERRMESS to QUIT
+        lda     BUTN0
+        ora     BUTN1
+        bmi     done_banner
+
+        lda     #OPC_JMP_abs
+        LDXY    #reloc__QuitFromIntBASIC
+        sta     reloc + (intbasic__WARM   - BASIC_START)
+        STXY    reloc + (intbasic__WARM+1 - BASIC_START)
+done_banner:
+
 ;;; --------------------------------------------------
 ;;; Bug fixes