Basic SNES Reproduction Board Guide

Please look at the main entry for more information on how to prepare the ROM file!

Here I will detail to you a quick and dirty guide to making SNES games using my basic custom boards. These boards are great for making simpler games, or transplanting working parts from any original SNES games that may be damaged in some way. There are two ROM socket types, but only one can be used at a time. This gives you the ability to:

  1. Make a game up to 1 MB (8 Mbit) using a 27C801 EPROM in the bottom set of sockets (note that ROM file must be swapbinned for use on the 27C801)
  2. Make a game up to 2 MB (16 Mbit) using a 27C160 EPROM in the top set of sockets
  3. Make a game up to 4 MB (32 Mbit) using a 29F032 + TSOP adapter board in the bottom set of sockets
  4. Make a game using a ROM chip from an original SNES board in the bottom set of sockets

This page will detail the hardware necessary for using the board in different modes – I will not be going over how to prepare the ROM file. You can view the main SNES tutorial to determine those details. And it is important to note, these boards cannot be used to replicate games that used specialty chips on their boards – this means you cannot make games that require: SuperFX, SuperFX2, DSP chips, SA-1, C4, S-DD1, or SPC7110.

Parts Needed (topside)

Here’s a breakdown of what parts you need based on what kind of game you’re making. All parts are located on the front of the board. For the discrete parts (resistors, capacitors, diodes, transistor) there are both surface mount pads and through-hole sockets available.

ROM – EPROM or EEPROM

Needed for: Every game
Part Number: Bottom set – 27C801, 29F032 (plus adapter), or original Mask ROM; Top set – 27C160
Function: Holds the ROM file (use only one ROM chip)
How to Program: Check the reproduction article for more information (Steps 1, 5, 6, and 7)

C1 – Electrolytic Capacitor

Needed for: Every game
Value: ~22 uF, at least 10 V rated
Function: Smooths out supply voltage for the board due to transients on the power supply, prevents quick changes in supply voltage when power is turned off

C2, C3, C4 – Ceramic Capacitors

Needed for: Every game (only use C3 for 27C801/Mask ROM, only use C4 for 27C160)
Value: ~0.1 uF, at least 10 V rated
Function: Filters out high-frequency noise that can interrupt the function of the chips on the board

C5, C6 – Ceramic Capacitors

Needed for: Games that save
Value: ~0.1 uF, at least 10 V rated
Function: Filters out high-frequency noise that can interrupt the function of the chips on the board

CIC – Region Lock-out Chip

Needed for: Every game (on un-modded SNES systems)
Part Number: 12F629, or the original CIC (only use one)
Function: Completes the region check with the SNES to let you play the game
Click here to jump to Step 9g of the main SNES tutorial to find out how to program the CIC, if yours isn’t pre-programmed

R1, D1, D2 – Resistors and Diodes

Needed for: Games that save
Value: ~1 kΩ for resistors, Schottky diodes (such as 1N914 or BAT81) for D1 and D2
Function: Combines the battery and SNES voltage rails to power the SRAM and keep it working after the SNES power is turned off

RB, RC, NPN – Resistors and NPN Transistor

Needed for: Games that save
Value: ~1 kΩ for RC; ~10 kΩ for RB; 2N2222, 2N3904, or equivalent for NPN
Function: Puts the SRAM into a low-power state during power-off

Battery

Needed for: Games that save
Part Number: C2032
Function: Keeps the SRAM on to retain data while power is off

SRAM

Needed for: Games that save
Part Number: 6264 (64K), 62256 (256K), or 1008 (1024K) series SRAM (be sure to get low standby current model)
Function: Holds save game data

74HC139 – SRAM Decoder (choose only one for LoROM or HiROM)

Needed for: Games that save
Part Number: 74HC139 (or equivalent)
Function: Activates the ROM or RAM, depending on the memory address being accessed

Solder Pad (frontside)

There is only one set of solder pads on the front of the board.

Decoder Bypass

Shorted: Enables output on boards without SRAM or the SRAM decoder
Open: Does nothing (do not short unless you do not have an SRAM decoder)

Solder Pads (backside)

There are a handful of solder pads you’ll need to bridge on the back of the board in order to make your game work.

HiROM/LoROM Selection

There are a few sets of three-way solder pads located in various locations on the board. You need to bridge two of the three depending on what bank type your game is.

SNES Mask or 27C801 Selection

If you are using the bottom set of sockets, you need to solder these two sets of pads on the back to the type of chip you are using. If you are using the (swapbinned) 27C801, then solder the middle pads to the right; if you are using the original ROM or a 29F032/29F033 on a TSOP adapter board, solder the middle pads to the left.

SRAM Enable

If you’re using SRAM, in the top left corner of the board bridge these pads together. If you reprogram your EPROM with a new game, you should disconnect these pads by desoldering them to reset the SRAM (they only need to be disconnected for a second). Then, resolder them together for your new game.

SRAM SIZE (SRAM selection pads)

These are another set of three-way solder pads, located in the top middle of the board. You need to bridge the set of pads (the middle and one to the top or bottom) depending on the size of the SRAM your game uses. Similar to the pads above, solder the two in the direction of the size of SRAM your game uses.

10 thoughts on “Basic SNES Reproduction Board Guide

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s