Added hexd and exec commands

apps/basic/basic.asm

@@ -15,7 +15,7 @@
 ;    - Unsupported functions cause FCERR, not a reset or REM
 ;    - modern backspace handling
 ;    - Added DROM/EROM/BANK0/BANK1 commands
-;    - CLOAD
+;    - Added CLOAD/HEXD/EXEC commands
 ;
 ;==================================================================================
 ; The updates to the original BASIC within this file are copyright Grant Searle
@@ -386,6 +386,8 @@ WORDS:  .BYTE   'E'+80H,"ND"
         .BYTE   'B'+80H,"ANK0"
         .BYTE   'B'+80H,"ANK1"
         .BYTE   'F'+80H,"ULL"
+        .BYTE   'H'+80H,"EXD"
+        .BYTE   'E'+80H,"XEC"
         .BYTE   80H             ; End of list marker
 
 ; KEYWORD ADDRESS TABLE
@@ -463,6 +465,8 @@ ZEROM   .EQU    0D3H
 ZBANK0  .EQU    0D4H
 ZBANK1  .EQU    0D5H
 ZFULL   .EQU    0D6H
+ZHEXD   .EQU    0D7H
+ZEXEC   .EQU    0D8H
 
 ; ARITHMETIC PRECEDENCE TABLE
 
@@ -1296,10 +1300,22 @@ CHKBANK1:
         JP      GETCHR
 CHKFULL:
         CP      ZFULL
-        JP      NZ,STDONJMP
+        JP      NZ,CHKHEXD
         LD      BC,FULL
         PUSH    BC
         JP      GETCHR
+CHKHEXD:
+        CP      ZHEXD
+        JP      NZ,CHKEXEC
+        LD      BC,HEXD
+        PUSH    BC
+        JP      GETCHR
+CHKEXEC:
+        CP      ZEXEC
+        JP      NZ,STDONJMP
+        LD      BC,EXEC
+        PUSH    BC
+        JP      GETCHR
         ; ------------
 STDONJMP:  
         SUB     ZEND            ; Is it a token?
@@ -4439,6 +4455,68 @@ TSTBIT: PUSH    AF              ; Save bit mask
 OUTNCR: CALL    OUTC            ; Output character in A
         JP      PRNTCRLF        ; Output CRLF
 
+; -------------------------------------------------------
+; Hex dump
+; syntax: HEXD start,length
+; -------------------------------------------------------
+HEXD:   CALL    GETNUM          ; Get start address
+        CALL    DEINT           ; Convert it to 16 bits
+        PUSH    DE              ; Save start address
+        CALL    CHKSYN          ; Make sure "," follows
+        .BYTE   ','
+        CALL    GETNUM          ; Get length
+        CALL    DEINT           ; Convert it to 16 bits
+        EX      (SP),HL         ; Save code pointer, get address
+HEXDLINE:
+        LD      A,D             ; Anything left to print?
+        OR      E
+        JP      Z,HEXDDONE
+        LD      A,H             ; Print four-digit address
+        CALL    HEXDBYTE
+        LD      A,L
+        CALL    HEXDBYTE
+        LD      B,16            ; Print up to 16 bytes per line
+HEXDLOOP:
+        LD      A,D             ; Stop at requested length
+        OR      E
+        JP      Z,HEXDEOL
+        LD      A,' '
+        CALL    OUTC
+        LD      A,(HL)
+        CALL    HEXDBYTE
+        INC     HL
+        DEC     DE
+        DJNZ    HEXDLOOP
+HEXDEOL:
+        CALL    PRNTCRLF
+        JP      HEXDLINE
+HEXDDONE:
+        POP     HL              ; Restore code pointer
+        RET
+
+HEXDBYTE:
+        PUSH    BC
+        CALL    BYT2ASC
+        LD      A,B
+        CALL    OUTC
+        LD      A,C
+        CALL    OUTC
+        POP     BC
+        RET
+
+; -------------------------------------------------------
+; Execute machine code
+; syntax: EXEC address
+; -------------------------------------------------------
+EXEC:   CALL    GETNUM          ; Get address
+        CALL    DEINT           ; Convert it to 16 bits
+        PUSH    HL              ; Save code pointer
+        CALL    EXECGO          ; Call address in DE
+        POP     HL              ; Restore code pointer
+        RET
+EXECGO: PUSH    DE              ; Put target address on stack
+        RET                     ; Continue there as a subroutine
+
 DROM:                           ; disable ROM
         RET     NZ
         LD      A,(BASTXT+1)    ; Full mode has program RAM below BIOS
@@ -4637,6 +4715,7 @@ CLREADBLOCK:
         call    BIOS_CAS_WAIT_SILENCE
         pop     hl
         ret
+
         ; Second block failed as well, error
 CLERR:  cp      1
         jr      z,CLECAL