microdrive: move the work buffer somewhere better

it was at 0x4000 to help debug, move it offscreen

diff --git a/Kernel/platform-zx128/microdrive.s b/Kernel/platform-zx128/microdrive.s
index 519c967..462c240 100644 (file)
--- a/Kernel/platform-zx128/microdrive.s
+++ b/Kernel/platform-zx128/microdrive.s
@@ -34,6 +34,12 @@
                .globl _mdv_hdr_buf
                .globl _mdv_len
 
+
+;
+;      Temporary 512 byte buffer used during boot only
+;
+MDV_BOOT_BUF   .equ    0xB000
+
 SECTORID       .equ    0x08            ; FIXME - set real format up!
 CSUM           .equ    0x0E            ; FIXME ditto
 
@@ -371,7 +377,7 @@ mdv_boot:
 ;
 ;      Spin up the boot volume
 ;
-               ld hl, #0x4000
+               ld hl, #MDV_BOOT_BUF
                ld (_mdv_buf), hl
                ld a, #1
                out (0xfe), a           ; blue
@@ -411,12 +417,12 @@ mdv_boot_loop:
                out (0xfe), a           ; loading stripes
                ld d, a                 ; high byte of address
                ld e, #0
-               ld hl, (_mdv_buf)
+               ld hl, #MDV_BOOT_BUF
                ld bc, #512
                ldir
                call done_all           ; check if we are complete
                jr z, mdv_boot_done
-               ld hl, #0x4000          ; we may have reloaded over this
+               ld hl, #MDV_BOOT_BUF            ; we may have reloaded over this
                ld (_mdv_buf), hl
 not_fk:                pop hl
                dec hl
@@ -432,7 +438,7 @@ mdv_bad:    cp #3
                jr not_fk
 
 mdv_boot_done:
-               ld a, #0x7
+               xor a
                out (0xFE), a
                ret