more sane directory name, updated binaries

src/kernal/iec/iec_pull_release.s

@@ -0,0 +1,88 @@
+// #LAYOUT# STD *        #TAKE
+// #LAYOUT# *   KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// Helper IEC routines to pull/release certain lines
+//
+// Order of operation is set for extra robustness, on non-emulated hardware
+// lines might need few cycles to stabilize (released CLK = DATA considered valid),
+// see page 10 of http://www.zimmers.net/anonftp/pub/cbm/programming/serial-bus.pdf
+//
+
+
+
+#if CONFIG_IEC
+
+
+iec_pull_atn_clk_release_data:
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_ATN_OUT          // pull
+	sta CIA2_PRA
+	
+	// FALLTROUGH
+
+iec_pull_clk_release_data:
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          // pull
+	sta CIA2_PRA
+!:
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    // release
+	bne iec_pull_release_end           // branch always
+
+iec_pull_clk_release_data_oneshot:
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_CLK_OUT          // pull
+	bne !-                             // branch always
+
+iec_release_atn_clk_data:
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT    // release
+	sta CIA2_PRA
+	
+	// FALLTROUGH
+	
+iec_release_clk_data:
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_DAT_OUT    // release
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    // release
+	jmp iec_pull_release_end
+	
+iec_release_clk_pull_data:
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_DAT_OUT          // pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    // release
+	bne iec_pull_release_end           // branch always
+
+iec_pull_data_release_atn_clk:
+
+	lda CIA2_PRA
+	ora #BIT_CIA2_PRA_DAT_OUT          // pull
+	sta CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_CLK_OUT    // release
+	sta CIA2_PRA
+	
+	// FALLTROUGH
+
+iec_release_atn:
+
+	lda CIA2_PRA
+	and #$FF - BIT_CIA2_PRA_ATN_OUT    // release
+
+	// FALLTROUGH
+
+iec_pull_release_end:
+
+	sta CIA2_PRA
+	rts
+
+
+#endif // CONFIG_IEC