Radica Upgrade MODs

Includes but not limited to: SNES, Genesis, Sega CD, PlayStation 1, Nintendo 64, Dreamcast, Game Gear and I guess the Virtual Boy.

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paulpsomiadis
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Radica Upgrade MODs

Post by paulpsomiadis » Tue Mar 13, 2007 1:44 pm

After some forum reading and some HEAVY research and testing...it's time to publish! 8)

Greetz and thanx go to those who made this possible - you know who you are! :wink:

Extra Radica Mods Tutorial
====================

We all know that a cartrige slot can be added to the Radica (thanks to @benheck), but there are other mods that can be done to improve this little marvel!

The picture below shows the locations of all these MODs on the underside of the Radica PCB...
Image

Link to Full Size Images (you WILL need this!)
==============================
http://www.box.net/shared/k2idfq3jif

Mod t€h 1st - Devsters SnK MOD
========================

1) Locate the HC174 chip on the underside of the Radica PCB (see picture at top of post)
2) Cut the trace as shown in the picture.
3) Solder pin 9 to the base of C31 (or any other +5v source)
4) Scrape the track in the location shown and solder a wire from here to cartrige slot pin B31.
5) Now play Sonic & Knuckles!

Mod t€h 2nd - 5v regulator MOD
=======================

1) Locate U7 on the underside of the Radica PCB (the voltage regulator)
2) Desolder the three small pins and remove AS MUCH solder as possible from the ground pad at the back.
3) Heat the ground pad, and 'carefully' use an exacto knife to lift U7 off the PCB.
4) Get your new 7805 voltage regulator.
5) Solder the 7805 Ground to any ground point (see picture)
6) Solder the input to the middle solder pad (see picture)
7) Solder the output to the right solder pad (see picture)
8.) You now have +5v VCC on the Radica PCB!

Mod t€h Final - Stereo sound!
======================
(thanks to @Blackpata for his initial and invaluable research)

This is my version of the stereo sound MOD done by @Blackpata, just with more / better diagrams!

The diagram below shows the Radica Audio section, and what will need to be removed / replaced...
Image

The Diagram below shows the MODDED Audio section afterward...
Image

Now for the instructions...(not for noobz!)
---stage 1---
1) Locate the resistor R16 to the right of the LM358 chip - remove R16.
2) Locate the resistor R12 to the left of the LM 358 chip - remove R12.
---stage 2---
3) Solder a 2.25nF bead capacitor onto a 47k resistor in parallel to each other.
4) Solder these where R12 used to be.
---stage 3---
5) Cut the via between R26 and R25.
6) Solder a link from the top of R19 to where the top of R16 USED TO be.
---stage 4---
7) Solder a wire to where the bottom of R16 used to be.
8.) Connect this wire to the POSITIVE side of the 10uF electrolytic capacitor.
9) Connect the 13.8mH inductor to the NEGATIVE end of the electrolytic capacitor.
10) Connect the 668.4pF bead capacitor to the NEGATIVE end of the electrolytic capacitor.
11) Connect the other end of the 668.4pF capacitor to GROUND.
12) Connect the POSITIVE of LEFT audio to the other end of the inductor.
13) Connect the NEGATIVE of LEFT audio to GROUND.
14) RIGHT audio comes from the standard audio points on the Radica PCB.
15) You now have (reasonable) Stereo sound.


Q & A Section
===========

Q) Can I use other inductor values - 13.8mH is hard to find!
A) ANY inductor of 4Mh or more (up to 13.8mH) can be used...I used 6mH for example!

Q) Can I build ---stage 4--- on some veroboard for safety?
A) Yes, it's better to do this. (It's what I did)

Q) Can I use normal components if I don't have access to SMT components?
A) Yes, by all means - I did this, as they are easier to get than SMT ones...just harder to solder onto teeny solder pads!

Q) What do you mean by 'reasonable' Stereo sound?
A) Although the Radica DOES seem to emulate all of the Yamaha 2612 sounds quite effectively, some of these seem to have incorrect volume levels - so it will sound like some music notes / sound effecs are missing.
If you listen REALLY carefully, they ARE there - just whisper quiet! (best using headphones)
Although this could be due to the fact that some of the operators on the Emulated YM2612 are not entirely correct...
A more precise sound MOD would involve DOUBLE LM358 amps, and all four channels would be amplified separately - then fed into a stereo mixing chip like on the REAL SEGA Megadrive (Genesis)...I might have a crack at this sometime in the future...
Another idea is to use variable resistors for the four inputs and two outputs, this would let you do all the work with just the one LM358 - but adjust the audio so you can hear the quieter channels...

@Devster - if you decide to mirror this tutorial on your page, please give me and @Blackpata credit for our work...

Thanks! 8)
Last edited by paulpsomiadis on Wed Mar 14, 2007 7:06 pm, edited 3 times in total.
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tom61
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Post by tom61 » Wed Mar 14, 2007 3:32 pm

Awesome. What is "t€h" though?

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Skyone
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Post by Skyone » Wed Mar 14, 2007 4:10 pm

T€h = the = the, I guess.

Nice compilation.

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Life of Brian
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Post by Life of Brian » Wed Mar 14, 2007 4:19 pm

Sweet. That's a lot of excellent info!

Is there any way you could make the text on the large Radica pic any sharper and larger? I've tried zooming in but it gets too fuzzy then.
dragonhead wrote:sweet. ive spent a third of my life on benheck!
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paulpsomiadis
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No can do!

Post by paulpsomiadis » Wed Mar 14, 2007 5:35 pm

Sorry @joedog86 - the text on the PCB picture HAS to be small, or it won't fit between components on the board. :roll:

This would cover them up and make it hard to see component labels... :?

Although I do see what you mean, the hi-res version 'should' fix this, but photobucket resizes it to 1024x768...

...I'll see what I can do.

@Skyone - correct!

T€h = the

==edit==

Image link changed, it now goes to online storage where you can get the full size images... :wink:
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werejag
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Post by werejag » Wed Mar 14, 2007 6:38 pm

how abouta bigger pic paulpsomiadis???

paulpsomiadis
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linky...

Post by paulpsomiadis » Wed Mar 14, 2007 7:07 pm

@werejag - use the link under the PCB image to get to my online shared pictures... :wink:

...then just DL the full size PCB image! 8)
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segasonicfan
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Post by segasonicfan » Wed Apr 25, 2007 5:09 am

Nice to finally have all this info in one place. That first full size image is a great reference too.

However, the 7805 is really unnecessary I think. The entire unit runs off +3.3.v (that's essentially a 7803 IC in there). Just get a 3v voltage regulator if you want to use high voltages. This will decrease the heat and power your Radica uses and is simply 10x more sensible and efficient. ;)

-Segasonicfan

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segasonicfan
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Post by segasonicfan » Wed Apr 25, 2007 5:10 am

Nice to finally have all this info in one place. That first full size image is a great reference too.

However, the 7805 is really unnecessary I think. The entire unit runs off +3.3v (that's essentially a 7803 IC in there). Just get a 3v voltage regulator if you want to use high voltages. This will decrease the heat and power your Radica uses and is simply 10x more sensible and efficient. ;)

-Segasonicfan

paulpsomiadis
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awrighty then...

Post by paulpsomiadis » Sun May 06, 2007 9:05 pm

Heh, I know it only runs on 3.3v, but I wanted to see if the 5v output would make any difference in compatibility - since the REAL Genny has a 5v output on the cart slot. :roll:

Unfortunately it didn't do anything (except for boosting the video output colours a bit) :P

Oh, and @segasonicfan - careful when hitting the POST button [doublepost...] :wink:
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segasonicfan
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Post by segasonicfan » Thu May 10, 2007 9:53 am

I went ahead and Stickified this since is the best source for Radica modding info on the forums. And it's all compiled into one nice thread... ;)

-Segasonicfan

paulpsomiadis
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Thanks!

Post by paulpsomiadis » Fri May 18, 2007 5:43 pm

Cheers @segasonicfan! 8)

Remember folks "sticky" is GOOD in forums - and BAD when you get superglue on your fingers!
:roll:
LOL! :lol:
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segasonicfan
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Post by segasonicfan » Mon Oct 08, 2007 12:55 am

now you should add my Radica S-video mod ;)

http://www.freewebs.com/vgmods/segamodifications.htm

-Segasonicfan

drjayphd
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Post by drjayphd » Sat Dec 15, 2007 2:15 am

segasonicfan wrote:now you should add my Radica S-video mod ;)

http://www.freewebs.com/vgmods/segamodifications.htm

-Segasonicfan
...your mod's a 404 page? :?: :?

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sam_thornley
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Post by sam_thornley » Mon Feb 18, 2008 8:28 am

drjayphd wrote:
segasonicfan wrote:now you should add my Radica S-video mod ;)

http://www.freewebs.com/vgmods/segamodifications.htm

-Segasonicfan
...your mod's a 404 page? :?: :?

Try Here http://forums.benheck.com/viewtopic.php?t=18907
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