From bfa46ced49592d1034c278e88f38a34a2df870fa Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@linux.intel.com>
Date: Fri, 1 Mar 2019 22:11:33 +0000
Subject: [PATCH] zxuno: add some helpers for putting the ZX Uno into 14Mhz
 mode etc

From a Fuzix perspective we want to turn on all the features regardless
---
 Kernel/dev/zx/zxuno.c | 99 +++++++++++++++++++++++++++++++++++++++++++
 Kernel/dev/zx/zxuno.h |  3 ++
 2 files changed, 102 insertions(+)
 create mode 100644 Kernel/dev/zx/zxuno.c
 create mode 100644 Kernel/dev/zx/zxuno.h

diff --git a/Kernel/dev/zx/zxuno.c b/Kernel/dev/zx/zxuno.c
new file mode 100644
index 00000000..15a5817c
--- /dev/null
+++ b/Kernel/dev/zx/zxuno.c
@@ -0,0 +1,99 @@
+#include <kernel.h>
+#include <printf.h>
+#include <zxuno.h>
+
+extern uint8_t fuller, kempston, kmouse, kempston_mbmask;
+
+/*
+ *	Support routines for the ZX Uno. Can be built into _DISCARD.
+ *
+ *	Turn on all the I/O devices and mark them present
+ *	Set the CPU to 14Mhz
+ *	Check for 50 v 60Hz (only 50 works right now)
+ *	Turn on the video and MMU modes
+ *
+ *	We don't do anything with the MMU and video.
+ */
+
+__sfr __banked __at 0xfc3b uno_ctrl;
+__sfr __banked __at 0xfd3b uno_data;
+
+uint8_t probe_zxuno(void)
+{
+	uint8_t n;
+	uint8_t c;
+	uno_ctrl = 0xff;
+	uno_data = 0x00;
+
+	/* Check if Uno is present */
+	for (n = 0; n < 64; n++) {
+		c = uno_data;
+		if (c == 0)
+			return 1;
+		if (c < 32 || c > 127)
+			return 0;
+	}
+	return 0;
+}
+
+/* Turn on all the I/O devices, and fire up the turbos */
+
+void configure_zxuno(void)
+{
+	uint8_t c;
+
+	uno_ctrl = 0xFF;
+	uno_data = 0x00;
+
+	kputs("ZX Uno Detected\n");
+	for (c = 0; c < 64; c++)
+		kputchar(uno_data);
+	kputchar('\n');
+	
+	uno_ctrl = 0;
+	if (uno_data & 0x80)
+		kputs("Warning: ZX Uno configuration is locked.\n");
+	else {
+		c = uno_data;
+		/* Contention off, Pentagon timing (as best), NMI off,
+		   DIVMMC on */
+		c &= ~0x10;	
+		c |= 0x66;
+		uno_data = c;
+	}
+	uno_ctrl = 6;
+	uno_data = 0x12;	/* Plug in stick is Kempston, alt is fuller */
+	kempston = 1;
+	fuller = 1;
+	kmouse = 1;
+
+	/* Vroooomm.... */	
+	uno_ctrl = 0x0B;
+	c = uno_data;
+	c &= 0x3C;
+	c |= 0x80;		/* 14MHz (don't set C0!!!) */
+	uno_data = c;
+
+	uno_ctrl = 0x0D;
+	c = uno_data;
+	c &= ~0x80;		/* SD on */
+	c |= 0x40;		/* Horizontal MMU and Timex video on
+				   (although we don't use them yet) */
+	uno_data = c;
+
+	uno_ctrl = 0x0F;
+	c = uno_data;
+	c &= 0xF8;		/* ULAplus, Radistano, Timex on */
+	uno_data = c;
+
+	/* FIXME: do we need to set radasctrl |= 3 */
+	uno_ctrl = 0xFB;
+	if (uno_data & 1) 	/* 60 HZ */
+		kputs("Warning 60Hz not yet supported.\n");
+}
+
+uint8_t locked_zxuno(void)
+{
+	uno_ctrl = 0;
+	return uno_data & 0x80;
+}
diff --git a/Kernel/dev/zx/zxuno.h b/Kernel/dev/zx/zxuno.h
new file mode 100644
index 00000000..f59c31ec
--- /dev/null
+++ b/Kernel/dev/zx/zxuno.h
@@ -0,0 +1,3 @@
+extern uint8_t probe_zxuno(void);
+extern void configure_zxuno(void);
+extern uint8_t locked_zxuno(void);
-- 
2.34.1