Update on Radica Genesis / Continued Talk

Post by **benheck** » Tue Dec 21, 2004 7:33 pm

The old topic was getting a bit long anyway...

I got an email from a Jonathan Scobbie who filled me in on some Genesis cart particulars...

The cart pinouts that say the first address line is A1... A0 is not included on the cart because it's 16 bit addressing.

Therefore, the Radica ROM has address lines A1-A21... 22 lines allowing 4 meg cartridges to run. Which is also the limit for Genesis. Apparently the last 2 address lines (A22 and A23) on the cart connector are for writing to battery-backed games.

So carts that don't work are because of compatibilty/regional issues, NOT memory addressing. The Radica can do it! Sure, it SAID a 4 meg ROM, but now I believe it!

Anyway, I'm finishing up my Sega Exodus layouts... It's gonna be 4.5" x 7.5" x 1.75", have a 3" screen, run off 4 AA's and have the cartridge slide down the back ALA Gameboy.

I noticed in EWJ2 the music seems a littlle "weak" in places. Couldn't the Radica just throw a Z80 in that glop-top? What did it do, synthesis?

SgtBowhack · Post by **SgtBowhack** » Tue Dec 21, 2004 7:43 pm

Ah-ha. That makes some sense

I wondered about that a little bit, actually (since if a 4MB ROM was working fine, it had to have everything handled somehow, right?) Like I said, try finding a Game Genie though to handle the region issues- it apparently can get by that somehow. Then again, it wouldn't surprise me if it required more connections than the Radica has for that to work either...

Post by **Sparkfist** » Tue Dec 21, 2004 8:03 pm

Cant wait to see it Ben, it really is a shame you couldnt get this one into the book. Oh well if anyone wants they can come and read about it after the book is released.

JackFrost22 · Post by **JackFrost22** » Tue Dec 21, 2004 8:30 pm

The radica is probably mssing the same chips as the gennesis 3

Post by **gannon** » Tue Dec 21, 2004 8:41 pm

as was said by me a few times also

I think it's a z80. If you could mod a radica to have that chip, then it'd be awesome

JackFrost22 · Post by **JackFrost22** » Tue Dec 21, 2004 9:14 pm

I think it would be to hard to mod a glob top Ive tried

SgtBowhack · Post by **SgtBowhack** » Tue Dec 21, 2004 9:42 pm

You know, the Genesis 2 also was missing the Z80, according to a bunch of sources. It's apparently not that big of a deal. How they got around it, I don't know...

Post by **gannon** » Tue Dec 21, 2004 9:54 pm

SgtBowhack wrote:You know, the Genesis 2 also was missing the Z80, according to a bunch of sources. It's apparently not that big of a deal. How they got around it, I don't know...

I could've swore that it was in the genesis 2, but it was combined with a few other chips, but it was completley removed in the genesis 3

SgtBowhack · Post by **SgtBowhack** » Tue Dec 21, 2004 10:26 pm

I don't have a Genesis 2 handy to check, but someone said that was one of the things that went with the size decrease *shrug*

gotchocolatemilk2 · Post by **gotchocolatemilk2** » Tue Dec 21, 2004 10:32 pm

I have a genesis 2 what should i look for

Post by **Sparkfist** » Tue Dec 21, 2004 10:38 pm

I have a Genesis v.2 and looking over it I see a chip that is labled as such;

Z84C0006FEC
Z80 CPU
9441 JP

The thing is tiny thoug only 0.4 inches on each side.

So correct me if I'm wrong here but, if we can some how hook that Z80 CPU up the the Radica Genesis we'll be able to play every game?

Edit one- Thought so everyone can see. Look on the left for a small square chip and its under some red text, that has the same symbol as the Z80 chip on my Genesis mobo so it should be the same chip. http://www.doomportables.org/images/sgenesis.png

Edit two-Found this looking for a way around the region lock that the genesis games had. "Still, beware that the Region Lock-up software based protection which has been used in a few dozen of Megadrive/Genesis games in the last year of the 16-bits era is not bypassed by the Nomad, and for this you would still need a GameGenie or an Action Replay for Megadrive/Genesis." The url is http://www.lik-sang.com/news.php?artc=3043 You need to scroll down and read the paragraph between the second and third groupe of Nomad pics.

gotchocolatemilk2 · Post by **gotchocolatemilk2** » Tue Dec 21, 2004 11:12 pm

is that a version 2 because the insides of my version 2 look completely different

Post by **Sparkfist** » Tue Dec 21, 2004 11:16 pm

Yeah it is to my knowlege, I know I have a v2 and its chips are not setup the same way (my z80 chip is on the other side of the board). It also doesnt have the head phone jack so I've 99% sure.

G-force · Post by **G-force** » Tue Dec 21, 2004 11:28 pm

Just thought I would point out... that I am psychic!!!
Heres proof!

http://benheck.com/ipw-web/bulletin/bb/ ... c&start=15

I foretold of Ben making a Genesis Portable! And the way you describe it is exactly the way I saw it, but it had a blue color scheme in my dream.
Ooooohhh...Creepy.....
I need a girlfriend.

Post by **Sparkfist** » Tue Dec 21, 2004 11:32 pm

That a little odd, or your just wishing hopefully for a new portable.

I need a girlfriend.

Dont we all.