dieskaarj / xiyoubu

Mega Drive hardware mod; Switchless region cycling, in-game reset, USB power and 68K overclock. Built on top of the MH-ATtiny88 and AD9833.

Xiyoubu - Mega Drive Does What Genesis-done.

Xiyoubu is a hardware console mod for the Mega Drive/Genesis that targets MH-ATtiny88 boards. It lets the Mega Drive change between 50Hz and 60Hz for video output (through scart) and enables language options for compatible software on the board. It also details a method for decreasing the power intake of the unit by way of a USB-C power port.

Xiyoubu will load the last saved profile on console power on.

Default config...

Controller

Menu I: (START + A + C + [...])

• B - In-Game Reset
• D-PAD
• • RIGHT - Region Cycle Forward (see: fig. 1)
• • LEFT - Region Cycle Backward (see: fig. 1)
• • UP - Save current region to EEPROM
• • DOWN - Check Overclocking (see: fig. 2)

Menu II: (START + B + [...])

• D-PAD
• • UP - Overclock (+) (Step up MAJ)
• • RIGHT - Overclock (+) (Step up MIN)
• • DOWN - Overclock (-) (Step down MAJ)
• • LEFT - Overclock (-) (Step down MIN)

Console

• Hold RESET to cycle regions
• Tap once to reset
• Tap twice to save region
• Tap thrice to enable/disable Xiyoubu controller handling (this option is saved and will be remembered after poweroff.)

Fig. 1

Region	LED
USA	Blue
PAL	Red
JAP	Magenta

Fig. 2

Mhz	Color
7+	Green
8+	Yellow
9+	Red
10+	Magenta
11+	Blue
12+	White

Status

• v1.04
• • Tested on: MD2 VA1 PAL

Features

• Controller Region Cycling
• Physical Region Cycling
• Restore Region On Power On
• In-Game Reset
• Overclock
• Installation Walkthrough
• Use Guide

Other Mega Drive related projects from the Author

• Ko-fi blog discussing the development of Xiyoubu: https://ko-fi.com/dieskaarj
• BlastEd - Mega Drive/Genesis Art Tool: https://dieskaarj.itch.io/blasted

Thank you for your hard work, research and resources

• SukkoPera: https://github.com/SukkoPera/MegaDrivePlusPlus
• TurBoss: https://github.com/TurBoss/MegaDrivePlusPlus/tree/overclock
• Smudger D: https://stompville.co.uk/?p=853
• SpenceKonde: https://github.com/SpenceKonde/ATTinyCore
• Raspberryfield: https://www.raspberryfield.life/2019/03/25/sega-mega-drive-genesis-6-button-xyz-controller/
• Charles MacDonald: https://gendev.spritesmind.net/forum/viewtopic.php?t=1262
• Liam Riordan: https://www.analog.com/media/en/technical-documentation/application-notes/AN-1070.pdf
• Atmel: http://ww1.microchip.com/downloads/en/DeviceDoc/atmel-9157-automotive-microcontrollers-attiny88_datasheet.pdf
• Analog Devices: https://www.analog.com/media/en/technical-documentation/data-sheets/ad9833.pdf

License

Xiyoubu (software) is Copyright © 2023 by David 'Erosion' Oberlin.

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 3 of the License, or (at your discretion) a 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.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.