From af3dcaf5fb68f3a7bbcbaa24c59d7ed52aca61da Mon Sep 17 00:00:00 2001
From: Joppe Blondel <joppe@joppeb.nl>
Date: Fri, 9 Oct 2026 17:07:17 +0200
Subject: [PATCH] csave-cload roundtrip irl works

---
 apps/basic/basic.asm | 47 +++++++++++++++++++++++++++++++++++++++++---
 memory.mk            |  4 ++--
 tape.asm             | 10 ++++++----
 3 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/apps/basic/basic.asm b/apps/basic/basic.asm
index bbaf2e3..0cc7d6f 100644
--- a/apps/basic/basic.asm
+++ b/apps/basic/basic.asm
@@ -4815,10 +4815,10 @@ CSAVEB: inc     hl              ; skip #
         inc     hl
         call    BYTESTOBLOCKS
         push    bc
-        ld      a,b             ; nr of blocks low byte
+        ld      a,c             ; nr of blocks low byte
         ld      (hl),a
         inc     hl
-        ld      a,c             ; nr of blocks high byte
+        ld      a,b             ; nr of blocks high byte
         ld      (hl),a
         inc     hl
         push    hl
@@ -4834,6 +4834,7 @@ CSAVEB: inc     hl              ; skip #
         inc     hl
         push    hl
         dec     e               ; count down str len
+        ld      a,e
         cp      0
         jr      nz,1$           ; repeat for the whole string
         exx
@@ -4843,9 +4844,49 @@ CSAVEB: inc     hl              ; skip #
         inc     hl
         ; Header block complete (rest of block is accepted garbage)
         call    BIOS_CAS_WRITE_BLOCK
-        
+        ld      a,'.'
+        call    OUTC
+        call    BIOS_CAS_WRITE_BLOCK
+        ld      a,'.'
+        call    OUTC
+        ld      a,250
+        call    BIOS_DELAY_MS
+        ld      a,250
+        call    BIOS_DELAY_MS
+        ld      a,250
+        call    BIOS_DELAY_MS   ; add a 750ms delay
         pop     bc              ; get back block count
         pop     de              ; get back start address
+        ld      a,b
+        or      c
+        jr      z,3$            ; no data blocks for a zero length
+2$:
+        ; load data into buffer
+        push    bc
+        call    BIOS_CAS_GET_BUFFER
+        ld      bc,128          ; block size
+        ld      a,0             ; raw type
+        ld      (hl),a
+        inc     hl
+        ex      de,hl           ; hl=src,de=dest
+        ldir                    ; copy the bytes
+        ex      de,hl           ; de back to being the src addr
+        call    BIOS_CAS_WRITE_BLOCK
+        ld      a,'.'
+        call    OUTC
+        call    BIOS_CAS_WRITE_BLOCK
+        ld      a,'.'
+        call    OUTC
+        pop     bc
+        dec     bc
+        ld      a,b
+        or      c
+        jr      nz,2$           ; repeat if not done
+3$:
+        ; All blocks are written
+
+        ld      hl,CLCLRF
+        call    PRS
 
         pop     hl
         pop     de
diff --git a/memory.mk b/memory.mk
index 85502b0..9a4dadd 100644
--- a/memory.mk
+++ b/memory.mk
@@ -14,8 +14,8 @@ BIOS_ROM_START          := 0x0080
 BIOS_ROM_SIZE           := 0x0780
 
 BASIC_ROM_START		:= 0x0800
-BASIC_ROM_SIZE		:= 0x2000
+BASIC_ROM_SIZE		:= 0x2200
 
 BIOS_RAM_START		:= 0xc000
 BIOS_WP_RAM_START	:= 0xc800
-BASIC_RAM_START		:= 0xcc00
+BASIC_RAM_START		:= 0xce00
diff --git a/tape.asm b/tape.asm
index 3e12d5a..486c304 100644
--- a/tape.asm
+++ b/tape.asm
@@ -636,7 +636,7 @@ gen_byte:
 ; -------------------------------------------------------
 gen_leader:
     ; short leader
-    ld          b,50            ; generate 50 short pulses
+    ld          b,100           ; generate 100 short pulses
 1$:
     call        gen_short
     dec         b
@@ -644,7 +644,7 @@ gen_leader:
     cp          0
     jr          nz,1$           ; repeat if not done
     ; long leader
-    ld          b,50            ; generate 50 long pulses
+    ld          b,100           ; generate 100 long pulses
 2$:
     call        gen_long
     dec         b
@@ -669,8 +669,9 @@ gen_leader:
 ; Writes the block stored in the block buffer
 ; -------------------------------------------------------
 write_block:
-    push        de
     push        bc
+    push        de
+    push        hl
     ; calculate the crc16 over the block
     ld          hl, BLOCK_BUFFER
     ld          a, BLOCK_SIZE-2 ; dont use crc value in block
@@ -706,8 +707,9 @@ write_block:
     ld          a,200
     call        delay_ms
 
-    pop         bc
+    pop         hl
     pop         de
+    pop         bc
     ret
 ; -------------------------------------------------------
 ; Strings