Shared Projects by ziggy

NOT TESTED

-U1 - 74HC04 -R1 - 1 k ohm -R2 - 100 k ohm -R3 - 10 k ohm -C1 - 100 nF -C2 - 10 nF

This is an adapter that will allow you to replace the 73LS00 with a 74LS139 on a SHVC-2J3B-01 PCB. This may only be useful for a single purpose: To put the fan translated Final Fantasy 5 on an authentic Final Fantasy 5 SFC cart that uses the 2J3B board by using three 27C080’s.

Final Fantasy V is a 16 Mebibit game, but the fan translation bumps the size up to 20 Mebibit. FF5 can be found on a 1J3B board, which has a single 36-pin mask ROM, in which case patching it with the fan translation is straight forward. But FF5 also came on a 2J3B board, which has two 32-pin mask ROMs and a 74LS00, in which case it’s not so easy to patch the fan translation without some rework.

One method is to use three 8 Mebibit EPROMs (such as 27C080) but an additional 74LS139 decoder is needed for this. In this case, the 74LS00 is no longer needed. Since the 74LS00 socket already has most of the connections needed, it is a convenient place to mount the new 139 (using this adapter). You will need to remove the 74LS00 from the board. And you will need to add two jumper wires: A21 (pin-14 on the 74LS139 that comes on the 2J3B) and /OE3 which you will connect to the /OE pin of your third EPROM. Be sure to connect EPROM 1 and 2 to the correct socket on the board.

There are drill holes on this adapter PCB located close to the OE3 and A21 pads. They are there so that you can more neatly route the jumper wires for those pads.

C1 is for a 0.1µF capacitor in the 0603 package.

If you want to use the SNES ROM Utility SwapBin function to prepare your 20 Mebibit fan translated ROM, you must first expand it to 24 Mebibits. What I suggest doing is copying the last 4 Mebibits and pasting it onto the end of the ROM and that will expand the ROM to 24 Mebibits. Then, use the split ROM and SwapBin functions of the SNES ROM Utility. That will output 3 files that are 8 Mebibits each, ready to burn to 27C080 or 27C801 EPROMs. Of the three split files, install the first one in socket P0, the second one in socket P1, and then wire the /OE pin from the third one to the OE3 pad on this adapter board. The third EPROM will have to be installed upside down on the bottom side of the board.

This is a simple circuit that will turn on an ATX power supply using a momentary switch. I made this specifically to use an AT style motherboard in an ATX case, however, you could use this generically in any case that you want to turn an ATX PSU on/off using a momentary switch.

The mounting hole is sized to fit a 6-32 screw so that you can mount the board using a standard motherboard standoff.

If using one of those common AT-to-ATX power adapters, you will most likely have to add a pin/wire for the +5VSB signal.

A parts list is silkscreened on the back of the PCB. Resistors and capacitors are 0805 size. You can use standard 2.54mm single row pin headers for the switch and PSU connections.

This has been tested using an AT motherboard and ATX power supply for several hours and found to work as intended. But as always, use at your own risk.

This circuit was taken from a post found on Stack Exchange. More info can be found here: https://electronics.stackexchange.com/questions/186841/momentary-button-as-switch

Tested with Framemeister and found to be working. I’ve read that this is also compatible with the OSSC. Use at your own risk.

http://dcemulation.org/?title=Dreamcast_480p_XRGB-mini_Framemeister_Cable

All the info you need is in the above link. The only additions I made are C6 decoupling capacitor (0.1µF) and JP1 (wire to SPST switch to select between 240p/480i and 480p modes). You can jump pin 6 inside the AV connector if that’s easier (one less conductor needed). You could also omit pin 7 or connect it to ground inside of the AV connector if you don’t care to switch between resolution modes.

Stereo to Mono Audio Adapter

Note, the web address on the PCB is no longer valid. The article that this is based off of has moved and can be found at the following address.

https://www.ranecommercial.com/legacy/note109.html

See Figure 2 from the above link. This takes a stereo audio signal and sums it to a mono output. Read the above linked page for more info.

TRS = Tip, Ring, Sleeve. T is the LEFT channel and R is the RIGHT channel (although it really doesn’t matter since you’re summing them). S is GROUND. All resistors are 0805 size. Use either mono output, they are both the same (or use both for a dual mono output).

R1/R2: 475 ohm, 1% tolerance R3: 20 k ohm, 1% tolerance

Use shielded cable for inputs/outputs for best results.