I got a Radica Genesis today

[Red5]

These are available in the UK now & I was considering a modding one to use actual Mega-Drive carts as well (I have a couple of dead MkI's knocking around for the edge conector) with the possibility of portablising it later. So Scherzo, did you get it working yet?

[scherzo]

No, unfortunately, it's a little out of my technical abilities for now. If feel if I try anything, I'll surely end up destroying the Radica. I've already taken out the ROM chip from it, so it's currently not fucntional. I'll just keep the parts around until I'm confident I can pull it off.

I'm working on a NOAC portable now instead. It'll be easier.

[G-force]

Practice soldering on some junk electronics until you're good. Thats the best way to learn how to solder with out breaking your stuff. Just solder a bunch of wires even if you aren't making anything.
Oddly, last night I had a dream that ben made a genesis portable using that thing, and I hadnt even read this yet! It was really cool looking and thats about all I can remember. I wonder what it means...

[scherzo]

Oh oh, I'm good at interpreting dreams. Watch...




It means you need to get out more. hehe, JK

[Red5]

I found a better DOC about the Genesis ROM chip/carts and the Connector Port which looks like it might be a bit more helpful: http://rafo.free.fr/Docs/Genesis_HARDWARE.TXT

[segasonicfan]

I got a Radica today so I can take a crack at it. I'm very good at soldering so wiring a genny cart port won't be a problem for me. Of course, I'm trying to figure out a couple things with this unit. If I do make it portable I'm going to want stereo sound and RGB. I don't know if the unit is capable of these things yet but I'm checking it out. The stereo sound is likely though, because it uses a small chip to convert it into mono sound. As for RGB, I don't see a chroma encoder but the lines are likely there, I just gotta find em. It's a shame the chip is one of those crappy black drop gooey kinds, without any of the pins showing. makes it hard to work with. The ROM is certainly 32MB and easily removable from the board, I just don't have a clue about what order the 44 pins need to be. Acording to the pinpout however, pin 32 is ground, same as A32. I'll look at it more and post my findings.

-Segasonicfan

[scherzo]

Good luck with that, fan. My Radica Gen is out of comission until some breakthru is made.

[shelter pitfall]

I got one too... I just need something to test it on... (I never owned a gen but wanted one)

[Sparkfist]

Well I just got an N64 game for $2.25 after shipping so I'm sure you could find a cheap game to test it on. And if any of you (is it) three finish that and make a better Nomad, Sega or Radica may end up kicking themselves for giving up such a worth while endever.

[Red5]

I spoke to DevStar about this because he seems to know his way around a Genesis... He's built a "Genesis Computer" with loads of extra memory & a hard drive!! Look here: http://devster.retrodev.com/pictures.html

Anyways back on topic, he believes it's most likely a custom chip (i.e not the same pinouts as a Genesis Carts) which will make the job a lot more difficult, though not impossible, to connect a cart slot. You can see the relevaent thread on his forum here: http://devster.proboards22.com/index.cg ... 1100894698

Also he has some information about the "unknown" pins on the other (older) docs linked earlier in this thread. I hope Ascii art works here!

Sega Connector (cART PORT)
--------------------------

The cartridge port pins are numbered 1A-32A and 1B-32B, left-to-right,
with the A row toward the back of the Genesis and the B row toward the front.

NOTE: I have changed the names from 1a, 2a etc. in Rick McTeagues Docs so as not to confuse 1A on the edge connector with the A1 signal etc.
I have also reversed the diagram from the others on the NET so that it corresponds with what you see when you have a REAL edge connector in your hand so you don't have to mentally reverse everything when looking at the diagram!



SideB SideA
(front) (Back)

-----------------
1B -|SL1 GND|- 1A
2B -|!H_RST +5V|- 2A
3B -|SR1 A8|- 3A
4B -|A9 A11|- 4A
5B -|A10 A7|- 5A
6B -|A18 A12|- 6A
7B -|A19 A6|- 7A
8B -|A20 A13|- 8A
9B -|A21 A5|- 9A
10B -|A22 A14|- 10A
11B -|A23 A4|- 11A
12B -|YS A15|- 12A
13B -|VSYNC A3|- 13A
14B -|HSYNC A16|- 14A
15B -|EDCLK A2|- 15A
16B -|!OE A17|- 16A
17B -|!CE_L A1|- 17A
18B -|!AS GND|- 18A
19B -|CLK D7|- 19A
20B -|!DTACK D0|- 20A
21B -|CAS D8|- 21A
22B -|D15 D6|- 22A
23B -|D14 D1|- 23A
24B -|D13 D9|- 24A
25B -|D12 D5|- 25A
26B -|!CE_H D2|- 26A
27B -|!RES D10|- 27A
28B -|!WR_L D4|- 28A
29B -|!WR_U D3|- 29A
30B -|!S_RES D11|- 30A
31B -|TIME +5V|- 31A
32B -|!CART_IN GND|- 32A
-----------------

(Copy & Paste into NOTEPAD and that should be readable)

Red5

[segasonicfan]

Thanks for the helpful info Red5
I tested out my Radica a little more and the 32MB board is definitely the 6-game Rom, the system turns on without it but won't show anything (obviously). Weird thing is, the system doesn't run off 5 or 6v. It has reeeally small voltage regulater that takes 5-6 and brings it down to a steady 3.27v which powers everything. Unfortunately when I removed the rom I lifted a lot of traces because this thing is 100% CRAP. It's one of those "drop" IC chips where they just drop the liquid cover over the silicon instead of making pins and processing it into a complete chip. This will make working with it much harder too...

Anyway, I'm really not a software person so my know-how for this ends with finding VCC and Ground. Pins 1 and 32 are ground by my readings and just about anything can be VCC since they all have 3.27v coming from them.

Anyway, I hope you software people can finish a pinout for this, I have many spare connectors and could easily make this the smallest portable genesis ever

-Segasonicfan

[segasonicfan]

...I forgot to mention a couple other things:
If the system and rom outputs only peak at 5v, are you sure normal Gen carts will work? I'm sure the ICs on their boards require 5v which would make this whole project impossible.

Also, do you guys think this thing has RGB? The UK one has a SCART connector, maybe somebody from across the pond will fill us in on that one. Also, I wonder if it outputs stereo sound...I think so cause I traced the audio line back to a simple amplifier IC that probably takes the two lines and connects them to mono sound. It can't be stereo L or anything either, cause Sonic for example swaps ring chime sounds from speakers R to L.

-Segasonicfan

[gannon]

well, if the cart ICs use 5V just patch in 5V from somewhere else.

[Red5]

As Gannon said you can probably pull the 5v from before the point where it is dropped to 3.7v on the board so that shouldn't be a problem.

Not sure about RGB, Scart sockets can be "full" (ie RGB) or "partial" (ie composite). In fact here in the UK you can buy little adapters that allow you to plug somthing using composite leads into a scart socket, it's still a composite input you just happen to be using the scart socket though. The same applies to the sockets on the back of the TV, most european TV's come with 2 scart sockets, the first one will always be a full RGB socket but to save money manufacturers will quite often make the second connector composite only... saving them about 50cents for about 5 pieces of wire!

Other mods to consider for this are:

1) Is a 50/60Hz mod possible?

2) Can you wire a 6-button controller onto it instead of the 3-button one supplied?

3) Can you wire in a second pad for 2-player games?

All those are pretty irrelevent of course until some one figures this out. I've been holding off buying one for now because I've already got the games that are built in, I'm waiting to see if anyone cracks this baby first!

[segasonicfan]

True, you can pull the 5v from elsewhere, but then I don't know if it'll last on batteries (4 AAs) as well...I guess we'll have to see. As for the 6-button controller, I'm 99% sure you can hook one up because the original Genesis systems were not desined with this in mind yet the two are compatible. If you check my web site I have a lot of detailed info on the Genesis 6-button controller and it would be pretty easy to hook up.

Well, I hope someone can figure out that pinout (Devster?), cause like I said, it's really out of my hands now.

-Segasonicfan