trs80m1: fix up model 3 NMI vector (its a JP xx xx) and turn it off at boot

Otherwise a couple of seconds in we get an NMI that randomly eats AF

diff --git a/Kernel/platform-trs80m1/trs80.s b/Kernel/platform-trs80m1/trs80.s
index 85b7e51..c50ad7a 100644 (file)
--- a/Kernel/platform-trs80m1/trs80.s
+++ b/Kernel/platform-trs80m1/trs80.s
@@ -97,8 +97,8 @@ init_early:
            ld (_trs80_model),a
            ld a,#0x74
            out (0xE0),a        ; Mask iobus, cassette
-           ld a,#0x40
-           out (0xE4),a        ; and NMI sources except motor off
+           xor a
+           out (0xE4),a        ; and NMI sources
            jr not_vg
 not_m3:
            ; Detect machine type (Model 1 or LNW80 or VideoGenie ?)
@@ -186,7 +186,7 @@ _rom_vectors:
 
            ; Model III only but just writing it does no harm
            ld hl,#fd_nmi_handler
-           ld (0x4049), hl
+           ld (0x404A), hl
            jp map_kernel
            
 ; outchar: Wait for UART TX idle, then print the char in A