Okay I found VCC, it's pin 33. It's actually running from a place market "VDD" whatever that means. I also scraped off all the white stuff under the ROM. They also use it on PS2 constroller and other PCBs. It's very annoying because it hinders the ability of seeing the traces. It's all off on mine though, so I can see where everything goes. I'll see if I can get a pic up so it can help out everyone.
So here's what I got-
1-ground
23-VCC (connected to 33)
32-ground
33-VCC (+3.27v)
I can also tell which traces run to which chips (the ones under the PCB, not the Main 'drop chip' cause it doesn't have pins) if anyone thinks that would help out. LMK!
-Segasonicfan
I got a Radica Genesis today
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Re: More Info...
Use code tags for ascii art.
I've got a bunch of Genesis games at home. I'd love to make a pocket-sized console for them, even if I don' t put a screen on it. VDD and VCC are often the same, or at least connected to each other.
Code: Select all
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
------------------
JackFrost22
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JackFrost22
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segasonicfan
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benheck
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I don't see how this could be that hard. The hardest part will be fixing the trace pads that got torn off 
Some games may not use as many leads on the card-edge because they may not have as much memory. Example, In the old days you need 16 address bits to address memory in a 64k space (which is why all the 6502 based computers had 64k, that was the limit of the 6502). Every additional address bit doubles the amount of memory you can access.
Systems such as the NES started using bankswitching chips in the carts (the MMC chips) to allow larger games to be sequentially loaded in. Kind of like disk-swapping!
The Atari 2600 could have accessed more than 4k per ROM (without bankswitching) but there weren't enough address pins on the cart edge connector (this they did to save 50 cents per machine by using only 24 pin connectors)
So if you have 20 address bits you could access 1024k, and by adding 1 pin you'd get that up to 2048 and so on. This is why different ROMs may have different #'s of pins going to them. A lot of the older Genesis games like Sonic 1 are just 512k.
Some games may not use as many leads on the card-edge because they may not have as much memory. Example, In the old days you need 16 address bits to address memory in a 64k space (which is why all the 6502 based computers had 64k, that was the limit of the 6502). Every additional address bit doubles the amount of memory you can access.
Systems such as the NES started using bankswitching chips in the carts (the MMC chips) to allow larger games to be sequentially loaded in. Kind of like disk-swapping!
The Atari 2600 could have accessed more than 4k per ROM (without bankswitching) but there weren't enough address pins on the cart edge connector (this they did to save 50 cents per machine by using only 24 pin connectors)
So if you have 20 address bits you could access 1024k, and by adding 1 pin you'd get that up to 2048 and so on. This is why different ROMs may have different #'s of pins going to them. A lot of the older Genesis games like Sonic 1 are just 512k.
I talked to a Genesis buff, and he says that it is possible that they removed the functionality for all games above 512K and just used the 512K roms. Is there an indication otherwise on the board?benheckc wrote:I don't see how this could be that hard. The hardest part will be fixing the trace pads that got torn off
Some games may not use as many leads on the card-edge because they may not have as much memory. Example, In the old days you need 16 address bits to address memory in a 64k space (which is why all the 6502 based computers had 64k, that was the limit of the 6502). Every additional address bit doubles the amount of memory you can access.
Systems such as the NES started using bankswitching chips in the carts (the MMC chips) to allow larger games to be sequentially loaded in. Kind of like disk-swapping!
The Atari 2600 could have accessed more than 4k per ROM (without bankswitching) but there weren't enough address pins on the cart edge connector (this they did to save 50 cents per machine by using only 24 pin connectors)
So if you have 20 address bits you could access 1024k, and by adding 1 pin you'd get that up to 2048 and so on. This is why different ROMs may have different #'s of pins going to them. A lot of the older Genesis games like Sonic 1 are just 512k.
Warranty-Voiding fun!
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shelter pitfall
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hmm, this is getting interesting..
even though they only know more software stuff, I'll poke around SWS2B forums. I think one time they pointed out segasonicfan's cdx portable or something.
even though they only know more software stuff, I'll poke around SWS2B forums. I think one time they pointed out segasonicfan's cdx portable or something.
Friend's site: http://rhapsody.shiroi-kaisou.net/
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JackFrost22
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I dont want to put a damper on your efforts but i think this genesis pad is a custom thing.
Only reason i think this is a custom cpu is a 68k cpu alone is just to big to be emulated in shuch a small area.
there are 2 chips which must be emulated 1 for sound 1 for game/graphics
I just dont think there is a chip out there powerful enough and that small to emulate the 68k cpu but i hope im wrong
If they did emulate the 68k source only then u will find not all games have sound as the genesis games sometimes used the 68k core for all video and sound processing skipping the sound chip.
Please someone prove me wrong just think its highly unlikely that its a full genesis system.
Only reason i think this is a custom cpu is a 68k cpu alone is just to big to be emulated in shuch a small area.
there are 2 chips which must be emulated 1 for sound 1 for game/graphics
I just dont think there is a chip out there powerful enough and that small to emulate the 68k cpu but i hope im wrong
If they did emulate the 68k source only then u will find not all games have sound as the genesis games sometimes used the 68k core for all video and sound processing skipping the sound chip.
Please someone prove me wrong
just think its highly unlikely that its a full genesis system.-
JackFrost22
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NIN, you keep saying "emulated". I'm sure nothing is emulated in the Radica. Everything is the hardware equivilent. And I don't think it's unlikely at all. I mean, how long have NES-On-A-Chip systems been in development? Many years actually. Probably since the Tristar64 came out. The Genesis and it's supporting hardware isn't that much more powerful.
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segasonicfan
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...and they already have the equivelent of a Dreamcast on a chip out. So Genesis on a chip is very likely. Also, there are other chips on the board for audio, video, etc. Not sure what the other chips to though but they must be for something! Hrmmm, lemme look them up and see what I can find...
-Segasonicfan
-Segasonicfan