feat(arnitech): a Blade autoboots the first program on device 8

With ARNITECH_BLADE, BASIC's cold start calls blade_autoboot before READY.: it
loads "*" from device 8 to BASIC's start, as LOAD"*",8 does, and BASIC then
ends that LOAD as a program's, which RUNs what it loaded. RUN/STOP held on the
Terminal Card, no Floppy, or no file goes on to READY.

src/kernal/arnitech/arnitech_autoboot.s

@@ -0,0 +1,40 @@
+;; #LAYOUT# STD *        #TAKE
+;; #LAYOUT# *   *        #IGNORE
+
+;
+; Autoboot of the Blade Firmware (mc64blade only, arnitech's ADR 0030): BASIC's cold start, before
+; READY., has a Blade LOAD"*",8, the first program on its internal drive's Floppy, and RUNs it.
+;
+; Out: carry clear if the program loaded, with X/Y the address after its end; carry set if
+; RUN/STOP is held on the Terminal Card, or the LOAD failed (no Floppy, no file, no drive).
+;
+
+!ifdef CONFIG_ARNITECH_BLADE {
+
+blade_autoboot:
+
+	jsr terminal_find
+	bcs @1
+	lda TERMINAL_STATUS, x
+	and #TERMINAL_STOP_HELD
+	beq @1
+	sec
+	rts
+@1:
+	lda #$01
+	ldx #<blade_autoboot_name
+	ldy #>blade_autoboot_name
+	jsr JSETNAM
+	lda #$00
+	ldx #$08
+	ldy #$00                           ; secondary address 0: to BASIC's start
+	jsr JSETFLS
+	lda #$00                           ; LOAD, not VERIFY
+	ldx TXTTAB+0
+	ldy TXTTAB+1
+	jmp JLOAD
+
+blade_autoboot_name:
+
+	!byte $2A                          ; "*"
+}