From 79dca016f2bf5fb9a11da530b308f5862e01884e Mon Sep 17 00:00:00 2001
From: Troy Schrapel <troy@visualrealmsoftware.com>
Date: Thu, 23 Nov 2023 16:33:53 +1030
Subject: [PATCH] Basic: Added initial LOAD/SAVE support

---
 code/6502/basic/basic_hbc56_core.asm | 124 ++++++++++++++++++++++++++-
 code/6502/basic/makefile             |  60 ++++++-------
 2 files changed, 153 insertions(+), 31 deletions(-)

diff --git a/code/6502/basic/basic_hbc56_core.asm b/code/6502/basic/basic_hbc56_core.asm
index 02b9654..0ce9921 100644
--- a/code/6502/basic/basic_hbc56_core.asm
+++ b/code/6502/basic/basic_hbc56_core.asm
@@ -20,6 +20,8 @@ BASIC_XPOS = HBC56_USER_ZP_START + 4
 BASIC_YPOS = HBC56_USER_ZP_START + 5
 BASIC_COLOR = HBC56_USER_ZP_START + 6
 
+LOAD_BYTE  = HBC56_USER_ZP_START + 7
+
 ; put the IRQ and NMI code in RAM so that it can be changed
 IRQ_vec         = VEC_SV+2      ; IRQ code vector
 NMI_vec         = IRQ_vec+$0A   ; NMI code vector
@@ -45,20 +47,140 @@ LAB_stlp
 
         jmp LAB_COLD
 
+hbc56OpenFile:
+	JSR	LAB_EVEX		; evaluate string, get length in A (and Y)
+        lda     Dtypef
+	bne +
+        ldx #$02
+        jmp LAB_XERR
++
+        JSR	LAB_22B6        ; pop string off descriptor stack, or from top of string
+                                ; space returns with A = length, X=pointer low byte,
+                                ; Y=pointer high byte
+        stx SAVE_X
+        sty SAVE_Y
+        tay
+        lda #0
+        sta (SAVE_X), y
+
+        lda #SAVE_X
+        sta $7f04               ; open file by name
+        rts
+
 ; -----------------------------------------------------------------------------
 ; hybc56Load - EhBASIC load subroutine (for HBC-56)   (TBA)
 ; -----------------------------------------------------------------------------
 hbc56Load
+        jsr hbc56OpenFile
+
+        ; save stack since NEW destroys it
+        tsx
+        inx
+        lda $100,x
+        sta SAVE_A
+        inx
+        lda $100,x
+        sta SAVE_Y
+
+        jsr LAB_1463    ; NEW
+
+        ; restore stack
+        lda SAVE_Y
+        pha
+        lda SAVE_A
+        pha
+
+        lda #3                          ;; how many newlines
+        sta SAVE_A
+
+        ; change input vector
+        lda #<fread
+        sta VEC_IN
+        lda #>fread
+        sta VEC_IN + 1
+
+        ; change output vector
+        lda #<nullOut
+        sta VEC_OUT
+        lda #>nullOut
+        sta VEC_OUT + 1
+
         rts
 
+
 ; -----------------------------------------------------------------------------
 ; hybc56Save - EhBASIC save subroutine (for HBC-56)   (TBA)
 ; -----------------------------------------------------------------------------
 hbc56Save
+        jsr hbc56OpenFile
+
+        ; change output vector
+        lda #<fwrite
+        sta VEC_OUT
+        lda #>fwrite
+        sta VEC_OUT + 1
+
+        jsr     LAB_14BD        ; call list function
+
+
+        lda $7f04               ; close file
+
+        ; revert output vector
+        lda #<hbc56Out
+        sta VEC_OUT
+        lda #>hbc56Out
+        sta VEC_OUT + 1
+
+        rts
+
+nullOut:
+        rts
+
+fwrite:
+        cmp #$0a
+        bne +
+        lda #$0d
+        sta $7f05
+        lda #$0a
++
+        sta $7f05
+        rts
+
+fread:
+        lda SAVE_A
+        beq +
+        dec SAVE_A
+        lda #$0d
+        sec
+        rts
++
+
+        lda $7f05               ; read byte from file
+        bne +
+
+        lda $7f04               ; close file
+
+        +tmsConsolePrint "\n Ready\n"
+
+        ; revert input vector
+        lda #<hbc56In
+        sta VEC_IN
+        lda #>hbc56In
+        sta VEC_IN + 1
+
+        ; revert output vector
+        lda #<hbc56Out
+        sta VEC_OUT
+        lda #>hbc56Out
+        sta VEC_OUT + 1
+
+        lda #$0d
++
+        sec
         rts
 
 ; -----------------------------------------------------------------------------
-; vector table - gets copied to VEC_IN in RAM
+; vector table - gets copied to VEC_CC in RAM
 ; -----------------------------------------------------------------------------
 LAB_vec
     !word    hbc56In         ; check for break (Ctrl+C)
diff --git a/code/6502/basic/makefile b/code/6502/basic/makefile
index 40f0bca..58e27bb 100644
--- a/code/6502/basic/makefile
+++ b/code/6502/basic/makefile
@@ -1,30 +1,30 @@
-# Troy's HBC-56 - BASIC makefile
-#
-# Copyright (c) 2021 Troy Schrapel
-#
-# This code is licensed under the MIT license
-#
-# https://github.com/visrealm/hbc-56
-#
-#
-
-ROOT_PATH=../
-
-default: basic_tms
-
-#basic_lcd.o: DISABLE_KERNEL_MODULES = TMS9918
-basic_tms.o: DISABLE_KERNEL_MODULES = LCD
-basic_uart.o: DISABLE_KERNEL_MODULES = LCD
-
-include $(ROOT_PATH)makefile
-
-%: %.o
-	copy /Y $<* ..\..\..\emulator\wasm\roms
-	$(HBC56EMU) --rom $<
-
-%lcd: %lcd.o
-	copy /Y $<* ..\..\..\emulator\wasm\roms
-	$(HBC56EMU) --lcd $(LCD_MODEL) --rom $<
-
-clean:
-	$(RM) *.o *.lmap
+# Troy's HBC-56 - BASIC makefile
+#
+# Copyright (c) 2021 Troy Schrapel
+#
+# This code is licensed under the MIT license
+#
+# https://github.com/visrealm/hbc-56
+#
+#
+
+ROOT_PATH=../
+
+default: basic_tms
+
+#basic_lcd.o: DISABLE_KERNEL_MODULES = TMS9918
+basic_tms.o: DISABLE_KERNEL_MODULES = LCD
+basic_uart.o: DISABLE_KERNEL_MODULES = LCD
+
+include $(ROOT_PATH)makefile
+
+%: %.o
+#copy /Y $<* ..\..\..\emulator\wasm\roms
+	$(HBC56EMU) --rom $<
+
+%lcd: %lcd.o
+#copy /Y $<* ..\..\..\emulator\wasm\roms
+	$(HBC56EMU) --lcd $(LCD_MODEL) --rom $<
+
+clean:
+	$(RM) *.o *.lmap