[apple2] light refactor of smartport code

Author: markjfisher

Changelog.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 
 - [network atari] Small tweak to ensure translation byte not lost when performing open, using stack instead of tmp variable which may get corrupt
+- [fuji apple2] Use "THE_FUJI" for fujinet device lookup instead of old hack for FUJI_DISK_0 - requires updated firmware
 
 ## [4.6.0] - 2024-09-01
 

apple2/src/bus/cc65/sp_dispatch.s

@@ -17,10 +17,9 @@ _sp_dispatch:
         
         ; the SP dispatch alters the return address by 3 bytes to skip the data below.
         ; it returs with any error codes.
-        .byte   $20             ; JSR - making this a byte so we can get exact location of address being called
-_sp_dispatch_address:
-        ; overwritten in sp_init to correct address
-        .word   $0000
+        ; The dispatch address is altered in sp_init
+        jsr     $0000
+_sp_dispatch_address = *-2
 
 dispatch_data:
         .byte   $00             ; command

apple2/src/bus/cc65/sp_init.s

@@ -12,12 +12,12 @@
         .include        "zp.inc"
         .macpack        cpu
 
-; C version 246 bytes, this is 104 or 110 bytes (65c02 vs 6502) as hand written asm
+; Find the SmartPort device that has a FujiNet NETWORK adapter on it.
+; Really we should search for the FUJI device on it, but historically that was hacked into the DISK_0 device for reasons I'll never ever understand.
 
 .proc _sp_init
 
 ; ptr1 = base (c701, c601, ...)
-; ptr2 = sp_detect_table
 
 .if (.cpu .bitand ::CPU_ISET_65SC02)
         stz     _sp_network
@@ -31,23 +31,16 @@
 .endif
 
         ; setup ptr1 to point to C700, it will decrease as we search cards
-        ldy     #$00
-        sty     ptr1
-        lda     #$c7
-        sta     ptr1+1
+        ldx     #$c7
+        stx     ptr1+1
 
         ; begin the detect loop
 main_loop:
-        lda     #<sp_detect_table
-        sta     ptr2
-        lda     #>sp_detect_table
-        sta     ptr2+1
-
         ldy     #$01
 
 four_loop:
         lda     (ptr1), y               ; Cn00 + y
-        cmp     (ptr2), y               ; table + y, which has extra bytes to align this loop
+        cmp     sp_detect_table, y      ; table + y, which has extra bytes to align this loop
         bne     no_match
         iny                             ; we look at Cn01, Cn03, Cn05, Cn07, so increment Y by 2
         iny
@@ -67,11 +60,11 @@ matched_four:
         lda     (ptr1), y
 .endif
         ; add 3, then store in dispatch address
-        ; clc - we know C is set because the previous cpy sets it in the comparison, so we can just add 2 here instead of 3 and save a byte
+        ; we know C is set because the previous cpy
         adc     #$02
         sta     _sp_dispatch_address
-        lda     ptr1+1
-        sta     _sp_dispatch_address+1
+        ; x is still Cn
+        stx     _sp_dispatch_address+1
 
 check_network:
         ; we set sp_is_init to stop sp_get_network_id from recursing
@@ -103,9 +96,9 @@ check_network:
 
 no_match:
         ; decrease ptr1+1 high byte of CnXX
-        dec     ptr1+1
-        lda     ptr1+1
-        cmp     #$c0
+        dex
+        stx     ptr1+1
+        cpx     #$c0
         bne     main_loop
 
         ; failed to find a network device on any card

apple2/src/bus/sp_find_fuji.c

@@ -6,11 +6,14 @@
 uint8_t sp_fuji_id = 0;
 
 bool sp_find_fuji() {
-	// this is a hack in firmware, the fujinet shares the same device as D0. for now...
-    int r = sp_find_device("FUJINET_DISK_0");
+    int r = sp_find_device("THE_FUJI");
 	if (r <= 0) {
-		sp_fuji_id = 0;
-		return false;
+		// backwards compatible hack check
+		r = sp_find_device("FUJINET_DISK_0");
+		if (r <= 0) {
+			sp_fuji_id = 0;
+			return false;
+		}
 	}
 	sp_fuji_id = (uint8_t) (r & 0xFF);
 	return true;