feat(iec): on a Blade the 1 ms wait counts on CIA1's timer B

A Blade has no VIC-II whose raster lines iec_wait1ms could count, so with
ARNITECH_BLADE it runs CIA1's timer B, which only the tape used, once for 1024
cycles, and waits for its START bit to clear. Its ICR flag would not do, as
the IRQ handler's read of the ICR clears it.

src/kernal/iec/iec_wait1ms.s

@@ -12,6 +12,28 @@
 ; 63 cycles, we need at least 17 full rasters to be 100% sure we wait enough
 
 
+!ifdef CONFIG_ARNITECH_BLADE {
+
+	; A Blade has no VIC-II: CIA #1's timer B, which only the tape used, counts 1024 cycles once
+	; (a little over 1 ms at the PAL clock of a Blade). Its START bit clears when it runs out;
+	; its ICR flag would not do, as the IRQ handler's read of the ICR clears it
+
+iec_wait1ms:
+
+	lda #$00
+	sta CIA1_TIMBLO
+	lda #$04
+	sta CIA1_TIMBHI
+	lda #%00011001                     ; one-shot, load the latch, start
+	sta CIA1_CRB
+@2:
+	lda CIA1_CRB
+	lsr
+	bcs @2
+	rts
+
+} else {
+
 !ifdef CONFIG_IEC {
 
 
@@ -55,3 +77,5 @@ wait_x_bars: ; additional entry point for delay in screen and tape support
 iec_wait_rts: ; dummy RTS, for very short waits
 
 	rts
+
+} ; CONFIG_ARNITECH_BLADE