more work on string support

src/basic/engine/varstr_alloc.s

@@ -15,11 +15,10 @@
 // - https://sites.google.com/site/h2obsession/CBM/basic/variable-format
 //
 // Input:
-// - DSCPNT+0, DSCPNT+1 - pointer to string descriptor, first pointed byte should contain desired length
+// - DSCPNT+1, DSCPNT+2 - pointer to string descriptor, first pointed byte should contain desired length
 //
 
 // XXX test this routine
-// XXX change DSCPNT to use standard descriptor format
 
 varstr_alloc:
 
@@ -61,7 +60,7 @@ varstr_alloc_retry:
 	// Create the back-pointer to the string descriptor
 
 	ldy #$00
-	lda DSCPNT+0
+	lda DSCPNT+1
 
 #if CONFIG_MEMORY_MODEL_60K
 	ldx #<FRETOP
@@ -71,7 +70,7 @@ varstr_alloc_retry:
 #endif
 
 	iny
-	lda DSCPNT+1
+	lda DSCPNT+2
 
 #if CONFIG_MEMORY_MODEL_60K
 	jsr poke_under_roms
@@ -84,12 +83,12 @@ varstr_alloc_retry:
 	dey                                          // $01 -> $00
 
 #if CONFIG_MEMORY_MODEL_60K
-	ldx #<DSCPNT
+	ldx #<DSCPNT+1
 	jsr peek_under_roms
 #elif CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
-	jsr peek_under_roms_via_DSCPNT
+	jsr peek_under_roms_via_DSCPNT_PLUS_1
 #else // CONFIG_MEMORY_MODEL_38K
-	lda (DSCPNT),y
+	lda (DSCPNT+1),y
 #endif
 
 	jsr varstr_FRETOP_down_A
@@ -101,7 +100,7 @@ varstr_alloc_retry:
 	lda FRETOP+0
 
 #if CONFIG_MEMORY_MODEL_60K
-	ldx #<DSCPNT
+	ldx #<FRETOP
 	jsr poke_under_roms
 #else // CONFIG_MEMORY_MODEL_38K || CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 	sta (FRETOP), y
@@ -111,9 +110,10 @@ varstr_alloc_retry:
 	lda FRETOP+1
 
 #if CONFIG_MEMORY_MODEL_60K
+	ldx #<DSCPNT+1
 	jsr poke_under_roms
 #else // CONFIG_MEMORY_MODEL_38K || CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
-	sta (DSCPNT), y
+	sta (DSCPNT+1), y
 #endif
 
 	// The end