trs80m1: boot loader now also handles selector

It's a bit tight but it fits. The code really wants a clean up and a squash

diff --git a/Kernel/platform-trs80m1/trs80load.s b/Kernel/platform-trs80m1/trs80load.s
index f2e70b9..e9ad460 100644 (file)
--- a/Kernel/platform-trs80m1/trs80load.s
+++ b/Kernel/platform-trs80m1/trs80load.s
@@ -12,6 +12,9 @@
 ;      load less empty space. On the other hand we've only got 256 bytes
 ;      of space to play in.
 ;
+;      We have zero free bytes, so to add anything you need to squash
+;      it a bit.
+;
 .area      BOOT        (ABS)
 .org       0x4200
 
@@ -36,15 +39,31 @@ start:
            ; Loader message
            ld de, #0x3C00
            call prints
-           .ascii 'TRS80Load 0.2m1\0'
+           .ascii 'TRS80LOAD 0.3M1\0'
            out (0x43),a                ; a is 0 on prints return
            in a,(0x43)
            or a
            jr z, bank_ok
+           ld hl,(3)
+           ld bc,#0x011f
+           ld a,c
+           ld (patch+3),a              ; patch the port
+           ld a,#0x08
+           ld (patch+1),a              ; patch the value
+           ld a,b
+           ld (patch2+1),a             ; pass the banker type
+           out (c),b
+           ld de,(3)
+           dec b
+           out (c),b
+           or a
+           sbc hl,de
+           jr nz, bank_ok
            call printse
-           .ascii 'Supermem not found\0'
+           .ascii 'BANKED MEMORY NOT FOUND\0'
 bad:       jr bad
-
+second_block:
+           .byte  0                    ; if we need to save use bank_ok+1 !
 bank_ok:
            ld bc, #0x4300              ; page aligned buffer we read into
            ld de, #FDCDATA             ; data port
@@ -106,10 +125,12 @@ flopin:       bit 1,(hl)
            inc b                       ; correct bc for next call
            jr nz, flopstat             ; passed FFFF ?
            ld b,#0x80                  ; go back to 8000 and change bank
-           in a,(0x43)
+           ld a,(second_block)
            or a
            jr nz, booted               ; already on second bank so boot
            ld a,#1                     ; switch to bank 2
+           ld (second_block),a
+patch:     ld a,#1                     ; patch for non supermem
             out (0x43),a
 flopstat:
            ld a, (hl)
@@ -119,7 +140,7 @@ flopstat:
            or a                        ; safe even though we rotated right
            ret z
            call printse
-           .ascii 'Read\0'
+           .ascii 'READ\0'
 fail:      jr fail
 
 
@@ -138,6 +159,5 @@ printsl:
 out:      jp (hl)
 
 booted:           call printse
-           .ascii 'Booting..\0'
-          xor a
-          jr 0x4300
+           .ascii 'BOOTING..\0'
+patch2:           ld a,#0