From 64dbdcdefb98a906ea3a26a0a49daf72af2516c8 Mon Sep 17 00:00:00 2001
From: Paul Gardner-Stephen <paul@servalproject.org>
Date: Sun, 28 Apr 2019 01:06:16 +0930
Subject: [PATCH] can now store a single line of basic into memory

---
 c64/basic/basic_insert_line.s  | 53 ++++++++++++++++++++++++++++++++++
 c64/basic/basic_main_loop.s    | 10 +++++++
 c64/basic/basic_shift_mem_up.s | 36 +++++++++++++++++------
 c64/basic/under_rom_routines.s |  3 +-
 4 files changed, 92 insertions(+), 10 deletions(-)

diff --git a/c64/basic/basic_insert_line.s b/c64/basic/basic_insert_line.s
index 9bad7286..f89ddfbc 100644
--- a/c64/basic/basic_insert_line.s
+++ b/c64/basic/basic_insert_line.s
@@ -6,6 +6,59 @@
 	;; Then all we have to do is push the rest of the BASIC text up,
 	;; and update the pointers in all following basic lines.
 basic_insert_line:
+
+	;; ASSUMES basic_find_line has been called to set the insert point.
+	;; We need to insert space for the link link token, the line number,
+	;; and the zero-terminated line itself.  This means 2+2+1 plus length
+	;; of tokenised string after the line number
+
+	;; But first, remember where the pointer will be, so that we can
+	;; put the line in there after.
+	lda basic_current_line_ptr+0
+	pha
+	lda basic_current_line_ptr+1
+	pha
+	
+	;; Get number of bytes in tokenised line after line number
+	lda tokenise_work2
+	sec
+	sbc tokenise_work1
+	;; Add on the four bytes space we need
+	clc
+	adc #5
+	tax
+	;; Make the space
+	jsr basic_shift_mem_up_and_relink
+
+	;; Get pointer back
+	pla
+	sta basic_current_line_ptr+1
+	pla
+	sta basic_current_line_ptr+0
+
+	inc $0427
+	;; Write the line number
+	ldy #2
+	ldx #<basic_current_line_ptr
+	lda basic_line_number+0
+	jsr poke_under_roms
+	iny
+	lda basic_line_number+1
+	jsr poke_under_roms
+
+	;; Now store the line body itself
+line_store_loop:
+	ldx tokenise_work1
+	lda $0200,x
+	inc tokenise_work1
+	ldx #<basic_current_line_ptr
+	iny
+	jsr poke_under_roms
+	lda tokenise_work1
+	cmp tokenise_work2
+	bne line_store_loop
+	
+	
 	sec
 	rts
 	
diff --git a/c64/basic/basic_main_loop.s b/c64/basic/basic_main_loop.s
index 8a08c8ad..d47eee95 100644
--- a/c64/basic/basic_main_loop.s
+++ b/c64/basic/basic_main_loop.s
@@ -91,6 +91,16 @@ ml_bad_line_number:
 
 	;; Got a valid line number.
 
+	;; Skip any spaces after the line number
+	ldx tokenise_work1
+skip_spaces:	
+	lda $0200,x
+	cmp #$20
+	bne +
+	inx
+	bne skip_spaces
+*	stx tokenise_work1
+	
 	;; First, clear all variables, so that we only have to shove BASIC text around.
 	;; (We could later remove this requirement, and the only effect should be
 	;; to slow things down, and that you might have to either CLR if there is no
diff --git a/c64/basic/basic_shift_mem_up.s b/c64/basic/basic_shift_mem_up.s
index 5f12ef69..281b84f0 100644
--- a/c64/basic/basic_shift_mem_up.s
+++ b/c64/basic/basic_shift_mem_up.s
@@ -30,31 +30,49 @@ basic_shift_mem_up_and_relink:
 	;; To make life simple for the copy routine that lives in RAM,
 	;; we have to adjust the end pointers down one page and set Y to the low
 	;; byte of the copy size.
-	tay
-	dec memmove_src+1
-	dec memmove_dst+1
+	lda memmove_src+0
+	sec
+	sbc memmove_size+0
+	sta memmove_src+0
+	lda memmove_src+1
+	sbc #0
+	sta memmove_src+1
+
+	lda memmove_dst+0
+	sec
+	sbc memmove_size+0
+	sta memmove_dst+0
+	lda memmove_dst+1
+	sbc #0
+	sta memmove_dst+1
+
+	;; Now make exit easy, by being able to check for zero on size high byte when done
+	inc memmove_size+1
+	
+	;; Then set Y to the number offset required
+	ldy memmove_size+0
 
 	;; Do the copy
 	jsr shift_mem_up
-	
-	;; Now fix the pointer for the BASIC lines
 
+	;; Now fix the pointer to the next line
+	
 	;; First, we need to point the current BASIC line
 	;; pointer to the previously present lines
 	stx tokenise_work3
 relink_up_next_line:	
-	ldx tokenise_work3
+	lda tokenise_work3
 	clc
 	adc basic_current_line_ptr+0
 	sta memmove_src+0
 	lda basic_current_line_ptr+1
 	adc #0
 	sta memmove_src+1
-	ldx #0
-	ldy #<basic_current_line_ptr
+	ldy #0
+	ldx #<basic_current_line_ptr
 	lda memmove_src+0
 	jsr poke_under_roms
-	inx
+	iny
 	lda memmove_src+1
 	jsr poke_under_roms
 
diff --git a/c64/basic/under_rom_routines.s b/c64/basic/under_rom_routines.s
index e5f45c10..0cc4cd4d 100644
--- a/c64/basic/under_rom_routines.s
+++ b/c64/basic/under_rom_routines.s
@@ -39,7 +39,6 @@ smu1:
 	lda (memmove_src),y
 	sta (memmove_dst),y
 	dey
-	cpy #$ff
 	bne smu1
 	dec memmove_src+1
 	dec memmove_dst+1
@@ -70,8 +69,10 @@ memmap_normal_routine:
 
 memmap_allram_routine:
 	sei
+	pha
 	lda #$04
 	sta $01
+	pla
 	rts
 
 ram_routines_end: