/* -*- mode: JavaScript; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* Copyright 2010-2013 Will Scullin <scullin@scullinsteel.com>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  No representations are made about the suitability of this
 * software for any purpose.  It is provided "as is" without express or
 * implied warranty.
 */

/*exported Thunderclock */

function Thunderclock(mmu, io, slot)
{
    var rom = [
        0x08,0x78,0x28,0x2c,0x58,0xff,0x70,0x05, // 00
        0x38,0xb0,0x01,0x18,0xb8,0x08,0x78,0x48,
        0x8a,0x48,0x98,0x48,0xad,0xff,0xcf,0x20, // 10
        0x1a,0xc8,0x68,0x68,0xba,0x8d,0xf8,0x07,
        0x0a,0x0a,0x0a,0x0a,0x8d,0x78,0x07,0x68, // 20
        0x68,0x68,0xa8,0x68,0x9a,0x09,0x04,0x48, 
        0x28,0x98,0xac,0x78,0x07,0xae,0xf8,0x07, // 30
        0x29,0x7f,0x48,0x50,0x0e,0xb8,0xa5,0x36,
        0xd0,0x04,0xe4,0x37,0xf0,0x0a,0xa9,0x08, // 40
        0x85,0x38,0x38,0x90,0x16,0x4c,0x50,0xc9,
        0xa9,0x0b,0x85,0x36,0xa9,0x5e,0x9d,0xb8, // 50
        0x04,0xa9,0x0a,0x9d,0x38,0x04,0xa9,0x00,
        0x9d,0x38,0x05,0x68,0xc9,0x25,0xf0,0x5c, // 60
        0xc9,0x26,0xf0,0x58,0xc9,0x3c,0xf0,0x54,
        0xc9,0x3e,0xf0,0x50,0xc9,0x23,0xf0,0x4c, // 70
        0xc9,0x5e,0xf0,0x5a,0xc9,0x21,0xf0,0x4a,
        0xc9,0x2a,0xf0,0x52,0xa2,0x20,0xc9,0x2c, // 80
        0xf0,0x52,0xa2,0x28,0xc9,0x2e,0xf0,0x4c,
        0xa2,0x30,0xc9,0x2f,0xf0,0x46,0xae,0xf8, // 90
        0x07,0x48,0xbd,0xb8,0x04,0xc9,0x21,0xf0,
        0x41,0xc9,0x5e,0xf0,0x0e,0x68,0x29,0x1f, // A0
        0x0a,0x38,0xe9,0x01,0x9d,0x38,0x04,0xa9,
        0x5e,0xd0,0x23,0x68,0x38,0xe9,0x41,0x30, // B0
        0x20,0xc9,0x16,0x10,0x1c,0xaa,0xbd,0x8d,
        0xcb,0x4c,0x04,0xcb,0x9d,0x38,0x05,0x4c, // C0
        0x2f,0xc9,0xa9,0x20,0x20,0xb7,0xca,0xa9,
        0x08,0x20,0xb7,0xca,0xa9,0x21,0x9d,0xb8, // D0
        0x04,0x4c,0x2f,0xc9,0x8a,0x20,0xb7,0xca,
        0xd0,0xf7,0x68,0xc9,0x0d,0xf0,0x13,0xc9, // E0
        0x20,0xf0,0x44,0x29,0x0f,0x20,0xcf,0xca,
        0xf0,0x02,0xa9,0x0a,0x9d,0x38,0x07,0x18, // F0
        0x90,0x35,0x20,0xcf,0xca,0x7d,0x38,0x07,
        0x48,0xa9,0x09,0x9d,0x38,0x06,0x20,0xcf, // 00
        0xca,0x48,0xde,0x38,0x06,0xd0,0xf7,0xa9,
        0x0a,0x9d,0x38,0x06,0x68,0x20,0xcf,0xca,
        0xde,0x38,0x06,0xd0,0xf7,0xa9,0x10,0x20,
        0xb7,0xca,0xd0,0xb2,0xba,0x68,0x68,0x98,
        0x48,0x68,0x68,0xa9,0x8d,0x48,0x9a,0xae,
        0xf8,0x07,0xac,0x78,0x07,0xbd,0xb8,0x03,
        0xdd,0x38,0x07,0xd0,0x0c,0x1d,0x38,0x07,
        0xf0,0x07,0xc9,0x40,0xd0,0x03,0x99,0x80,
        0xc0,0x68,0xa8,0x68,0xaa,0x68,0x28,0x60,
        0x68,0xa9,0x18,0x20,0xb7,0xca,0xa9,0x08,
        0x20,0xb7,0xca,0xa9,0x09,0x9d,0x38,0x06,
        0x20,0xcf,0xca,0xc9,0x0a,0x30,0x02,0xa9,
        0x00,0x48,0xde,0x38,0x06,0xd0,0xf1,0x20,
        0xcf,0xca,0xc9,0x0d,0x30,0x02,0xa9,0x00,
        0x48,0xbd,0x38,0x05,0xf0,0x04,0xc9,0x23,
        0xd0,0x5e,0xa0,0x00,0x68,0xc9,0x0a,0x30,
        0x04,0xc8,0x38,0xe9,0x0a,0x48,0x98,0xa2,
        0x00,0x20,0xa6,0xca,0x68,0x20,0xa6,0xca,
        0xac,0xf8,0x07,0xb9,0x38,0x05,0xd0,0x2a,
        0xa9,0xaf,0x20,0xa8,0xca,0x68,0xa0,0x04,
        0x68,0x20,0xa6,0xca,0x68,0x20,0xa6,0xca,
        0x88,0xf0,0x07,0xa9,0x3b,0x20,0xa8,0xca,
        0xd0,0xee,0xa9,0xa0,0x8d,0x05,0x02,0xb9,
        0xf3,0xcb,0xf0,0x19,0x20,0xa8,0xca,0xc8,
        0xd0,0xf5,0xa9,0x00,0x48,0xa0,0x05,0x20,
        0xaf,0xca,0x68,0x20,0xa6,0xca,0x68,0x20,
        0xa6,0xca,0x88,0xd0,0xf2,0x4c,0x9a,0xca,
        0x68,0xaa,0x68,0x0a,0x0a,0xa8,0x8a,0x0a,
        0x0a,0x48,0xae,0xf8,0x07,0xbd,0x38,0x05,
        0xa2,0xa0,0xc9,0x3c,0xb0,0x02,0xa2,0xa2,
        0x8a,0xa2,0x00,0x20,0xa8,0xca,0xb9,0xa3,
        0xcb,0xc8,0x20,0xa8,0xca,0xc9,0xa0,0xd0,
        0xf5,0x68,0xa8,0xb9,0xbf,0xcb,0xc8,0x20,
        0xa8,0xca,0xc9,0xa0,0xd0,0xf5,0x68,0x20,
        0xa4,0xca,0x68,0x20,0xa6,0xca,0x20,0xb3,
        0xca,0xa0,0x03,0x68,0x20,0xa4,0xca,0xd0,
        0x03,0x20,0xa6,0xca,0x68,0x20,0xa6,0xca,
        0x88,0xf0,0x09,0xa9,0xba,0x20,0xa8,0xca,
        0x68,0x4c,0x29,0xca,0xac,0xf8,0x07,0xb9,
        0x38,0x05,0xc9,0x25,0xf0,0x04,0xc9,0x3e,
        0xd0,0x50,0xa0,0x41,0xad,0x0c,0x02,0xc9,
        0xa0,0xd0,0x02,0xa9,0x30,0x0a,0x0a,0x0a,
        0x0a,0x8d,0x20,0x02,0xad,0x0d,0x02,0x29,
        0x0f,0x0d,0x20,0x02,0xc9,0x12,0x30,0x02,
        0xa0,0x50,0xc9,0x00,0xd0,0x04,0xa9,0x12,
        0xd0,0x09,0xc9,0x13,0x30,0x16,0xf8,0x38,
        0xe9,0x12,0xd8,0xa2,0x0c,0x48,0x20,0xff,
        0xca,0x29,0x0f,0x20,0xa4,0xca,0x68,0x29,
        0x0f,0x20,0xa6,0xca,0xa2,0x14,0x20,0xb3,
        0xca,0x98,0x20,0xa8,0xca,0xa9,0x4d,0x20,
        0xa8,0xca,0x8a,0xa8,0xa9,0x8d,0x20,0xa8,
        0xca,0x4c,0x24,0xc9,0xf0,0x0d,0x09,0x30,
        0x09,0x80,0x9d,0x00,0x02,0xe8,0x60,0xa9,
        0xac,0xd0,0xf5,0xa9,0xa0,0xd0,0xf1,0x99,
        0x80,0xc0,0x09,0x04,0x99,0x80,0xc0,0x20,
        0xc7,0xca,0x49,0x04,0x99,0x80,0xc0,0x20,
        0xca,0xca,0x48,0x48,0x68,0x68,0x60,0x48,
        0xa9,0x04,0x9d,0xb8,0x06,0xa9,0x00,0x9d,
        0xb8,0x05,0xb9,0x80,0xc0,0x0a,0x7e,0xb8,
        0x05,0x68,0x48,0x29,0x01,0x99,0x80,0xc0,
        0x09,0x02,0x99,0x80,0xc0,0x49,0x02,0x99,
        0x80,0xc0,0x68,0x6a,0x48,0xde,0xb8,0x06,
        0xd0,0xe0,0x68,0xbd,0xb8,0x05,0x18,0x6a,
        0x6a,0x6a,0x6a,0x60,0x48,0xae,0xf8,0x07,
        0xbd,0x38,0x04,0x9d,0xb8,0x06,0x20,0x50,
        0xcb,0x68,0x48,0x20,0x4c,0xcb,0x68,0x48,
        0x49,0xf8,0x20,0x4c,0xcb,0xa2,0xa0,0x20,
        0x69,0xcb,0xa2,0xa0,0x20,0x69,0xcb,0xa0,
        0x18,0x20,0x60,0xcb,0xae,0xf8,0x07,0xde,
        0xb8,0x06,0xd0,0xda,0x68,0xa0,0xbc,0xca,
        0xd0,0xfd,0x88,0xd0,0xfa,0x4c,0x2f,0xc9,
        0x48,0x90,0x05,0x20,0x50,0xcb,0xf0,0x03,
        0x20,0x59,0xcb,0x68,0x0a,0xd0,0xf1,0x60,
        0xa2,0x50,0x20,0x69,0xcb,0xa0,0x28,0xd0,
        0x07,0xa2,0x18,0x20,0x69,0xcb,0xa0,0x44,
        0xa2,0x13,0xca,0xd0,0xfd,0x88,0xd0,0xf8,
        0x60,0xac,0x78,0x07,0xa9,0x20,0x99,0x80,
        0xc0,0xea,0xea,0xea,0x49,0x20,0x99,0x80,
        0xc0,0xea,0xea,0xea,0x49,0x20,0x99,0x80,
        0xc0,0xea,0xea,0xea,0x49,0x20,0x99,0x80,
        0xc0,0xca,0xd0,0xe0,0x60,0x64,0xe4,0x24,
        0xa4,0x14,0x94,0x54,0xd4,0x74,0xf4,0x34,
        0xb4,0x04,0x84,0x44,0xc4,0x2c,0x3c,0x5c,
        0x4c,0x1c,0x0c,0x53,0x55,0x4e,0x20,0x4d,
        0x4f,0x4e,0x20,0x54,0x55,0x45,0x20,0x57,
        0x45,0x44,0x20,0x54,0x48,0x55,0x20,0x46,
        0x52,0x49,0x20,0x53,0x41,0x54,0x20,0x45,
        0x52,0x52,0x20,0x4a,0x41,0x4e,0x20,0x46,
        0x45,0x42,0x20,0x4d,0x41,0x52,0x20,0x41,
        0x50,0x52,0x20,0x4d,0x41,0x59,0x20,0x4a,
        0x55,0x4e,0x20,0x4a,0x55,0x4c,0x20,0x41,
        0x55,0x47,0x20,0x53,0x45,0x50,0x20,0x4f,
        0x43,0x54,0x20,0x4e,0x4f,0x56,0x20,0x44,
        0x45,0x43,0x20,0xae,0xb0,0xb0,0xb0,0x00,
        0xae,0xb0,0xb0,0xb0,0x00,0xa0,0xa0,0xc1,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff
    ];

    var LOC = {
        CONTROL: 0x80
    };

    var FLAGS = {
        DATA: 0x01,
        CLOCK: 0x02,
        STROBE: 0x04
    };

    function _init() {
        LOC.CONTROL += slot * 0x10;
    }

    var auxRomFn = {
        start: function auxRom_start() {
            return 0xc8;
        },
        end: function auxRom_end() {
            return 0xcf;
        },
        read: function auxRom_read(page, off) {
            return rom[(page - 0xc8) * 256 + off];
        },
        write: function auxRom_write() {}
    };

    var _command = 0;
    var _bits = [];

    function _calcbits() {
        function shift(val) {
            for (var idx = 0; idx < 4; idx++) {
                _bits.push((val & 0x08) !== 0);
                val <<= 1;
            }
        }
        function shiftBCD(val) {
            shift(parseInt(val / 10, 10));
            shift(parseInt(val % 10, 10));
        }

        var now = new Date();
        var day = now.getDate();
        var weekday = now.getDay();
        var month = now.getMonth() + 1;
        var hour = now.getHours();
        var minutes = now.getMinutes();
        var seconds = now.getSeconds();

        _bits = [];
        shift(month);
        shift(weekday);
        shiftBCD(day);
        shiftBCD(hour);
        shiftBCD(minutes);
        shiftBCD(seconds);
    }

    function _access(off, val) {
        switch (off) {
        case LOC.CONTROL:
            if (val !== undefined) {
                if (val & FLAGS.STROBE) {
                    if ((_command & 0x78) == 0x18) {
                        _calcbits();
                    }
                }
                _command = val;
            } else {
                if (_bits.pop()) {
                    _command |= 0x80;
                } else {
                    _command &= 0x7f;
                }
            }
            break;
        }
        return _command;
    }

    _init();

    return {
        start: function thunderclock_start() {
            io.registerSwitches(this, LOC);
            return 0xc0 + slot;
        },
        end: function thunderclock_end() {
            return 0xc0 + slot;
        },
        read: function thunderclock_read(page, off) {
            mmu.auxRom(slot, auxRomFn);

            return rom[off];
        },
        write: function thunderclock_write() {
            mmu.auxRom(slot, auxRomFn);
        },
        ioSwitch: function thunderclock_ioSwitch(off, val) {
            return _access(off, val);
        }
    };
}