diff --git a/m28f.c b/m28f.c
new file mode 100644
index 0000000..97224ed
--- /dev/null
+++ b/m28f.c
@@ -0,0 +1,98 @@
+/*
+ * This file is part of the flashprog project.
+ *
+ * Copyright (C) 2026 Nico Huber <nico.h@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdint.h>
+
+#include "flash.h"
+#include "chipdrivers/memory_bus.h"
+
+static int write_m28f_1(struct flashctx *flash, unsigned int pos, uint8_t val)
+{
+	const chipaddr base = flash->virtual_memory;
+	unsigned int tries;
+
+	for (tries = 25; tries > 0; --tries) {
+		chip_writeb(flash, 0x40, base);
+		chip_writeb(flash, val, base + pos);
+		programmer_delay(10);
+
+		chip_writeb(flash, 0xc0, base);
+		programmer_delay(6);
+
+		if (chip_readb(flash, base) == val)
+			return 0;
+	}
+
+	msg_cerr("Write failed at 0x%06x.\n", pos);
+	return 1;
+}
+
+int write_m28f(struct flashctx *flash, const uint8_t *src, unsigned int pos, unsigned int len)
+{
+	const chipaddr base = flash->virtual_memory;
+	const unsigned int limit = pos + len;
+	int ret;
+
+	for (; pos < limit; ++pos, ++src) {
+		if (*src == 0xff) /* skip no-op writes */
+			continue;
+
+		ret = write_m28f_1(flash, pos, *src);
+		if (ret)
+			goto return_to_read_mode;
+	}
+
+return_to_read_mode:
+	chip_writeb(flash, 0x00, base);
+	return ret;
+}
+
+int erase_m28f(struct flashctx *flash, unsigned int addr, unsigned int blocksize)
+{
+	const chipaddr base = flash->virtual_memory;
+	unsigned int tries, pos;
+	int ret;
+
+	/* Programming everything to 0 is required. */
+	for (pos = 0; pos < blocksize; ++pos) {
+		ret = write_m28f_1(flash, pos, 0x00);
+		if (ret)
+			goto return_to_read_mode;
+	}
+
+	for (pos = 0, tries = 1000; tries > 0; --tries) {
+		chip_writeb(flash, 0x20, base);
+		chip_writeb(flash, 0x20, base);
+		programmer_delay(10*1000);
+
+		for (; pos < blocksize; ++pos) {
+			chip_writeb(flash, 0xa0, base + pos);
+			programmer_delay(6);
+
+			if (chip_readb(flash, base) != 0xff)
+				break;
+		}
+		if (pos == blocksize)
+			goto return_to_read_mode;
+	}
+
+	msg_cerr("Erase failed at 0x%06x.\n", pos);
+	ret = 1;
+
+return_to_read_mode:
+	chip_writeb(flash, 0x00, base);
+	return ret;
+}