A "2-in-1-portable?"

Chu_Chu · Post by **Chu_Chu** » Mon Feb 06, 2006 7:06 pm

Arright, im new to this forum (registered like a few minutes ago).
Me and my girlfriend's got an idea about making a portable. We were just discussing wich games would be most entertaining to play for a portable Mega Drive... or Genesis as you might call it on your side of the planet. However we figured that what we would look most forwards for to play would already exist in the Radicas, verision 1 and 2. Basically for the Sonic games of course.

So we thought that it would be kinda neat to have a portable "Genesis" without the cart slot. But instead using what's already inside Radica 1 and 2, for the same portable. So in a way combining them both.

How possible would that be?

SgtBowhack · Post by **SgtBowhack** » Mon Feb 06, 2006 7:17 pm

You could just... wire the Radica ROM to a cartridge and then add the cart slot and make a more simple portable. Do that for both Radicas and you'll be set

Chu_Chu · Post by **Chu_Chu** » Mon Feb 06, 2006 7:33 pm

I guess that's no bad idea actually. Wondering though, how easy it would be to wire the Radica rom to the actual cart? Yeah, planning to start up the first try so i guess im a newbie.

Fanboy · Post by **Fanboy** » Mon Feb 06, 2006 7:35 pm

Hmm, I recall someone working on a similar project a while back. They managed to attatch a switch between both ROMS, so you could play either one...

Chu_Chu · Post by **Chu_Chu** » Mon Feb 06, 2006 7:42 pm

Yeah that was sort of the idea... cool to know that it'd be possible. Seems a bit complicated, how to attach both Radicas to the same controller... or am i just imagening that it'd be a problem?

Fanboy · Post by **Fanboy** » Mon Feb 06, 2006 8:07 pm

As far as I know, it seems pretty simple. You'd have to ask someone who knows better than me of the functions of the Megadrive...

SgtBowhack · Post by **SgtBowhack** » Mon Feb 06, 2006 8:21 pm

Wiring to the cart shouldn't be too hard... I think there were some schematics somewhere as far as how to do it. Would be best to use some 32Mbit game, since the Radica ROM uses all of the address pins, I believe. You could probably do it anyway, but it'd require more precision. The ROM is smaller than normal too, so it wouldn't exactly be a drop-in replacement.

Here's what you do to switch the ROMs:
Disconnect the voltage pin from the ROM on the board. Wire all pins from the second Radica ROM onto the pins of the first (just stack the ROMs on the board), except for the voltage pin. Connect both voltage pins to a SPDT switch (I think it's SPDT), with center connected to voltage (I think it's +5V but it could be +3.3V), and each of the outer pins connected to the voltage pins of each ROM, respectively. Now the switch turns the power on one ROM only. Yay. You could even ground the other ROM if you wanted, rather than leaving it floating using a DPDT switch:

G V
1 2
V G

where G = ground, V = voltage, 1 and 2 are the voltage pins of the ROM.

xriverfalconx · Post by **xriverfalconx** » Wed Feb 15, 2006 7:26 pm

Make sure you wire the cart the the FIRST genesis plug and play system, not the second one or the streetfighter one. I tried the street fighter one first and soon found out the hard way that the settings are a bit different. Stick to the original one with sonic 1 before soldering on the cart.

Also, soldering the cart slot isn't that difficult, just be very patient and start on the bottom of the board soldering from the board to the cart on wire at a time. That's all I can really say for this...have fun!

Tomorrow, I'm going to try one more time finishing up my genesis project, however, this time, I have a good helper helping me take things off at work. I'm sure I'll have a better chance finishing my portable this time around =P