Upcoming Sega MegaDrive modded consoles

[retromod]

I will offer a series of modded Sega Megadrives (model 1 and 2) beginning 2015.

The base are refurbished devices with an unique design:
 






function keys and label are in silver. blue power led (yellow in setup mode).  Delivered with manual, controller (in similar design) and modern power supply.

built in:
- surround sound mod (for best sound ever on a megadrive)
- RGB enhanced output (for one of the best video signals) via SCART adapter (includes stereo).
- pause function (via controller)
- tube tv emulation for flat screens  (disable if required)
- 50/60 Hz and region switch (handled via controller)

there are no additional switches.

[zapiy]

Great work fella.

[retromod]

Yesterday I completed the design. Added an internal dust protection to the cartridge slot (which looks much nicer now as it is completly black inside). Also added black shields to the connectors on the back so pcb is now invisible if you look on the back.

The RGB mod works fine but have some glitches due to technical limitations on the custom chips. Try to improve that by directly hook to the VDP.

The surround mod is working! Better and bigger sound than the "plain" sound coming out of a stock megadrive console.  Also having an amp included to increase sound level to normal (not using the stereo output header and so do not follow volume control on the console). You are able to switchless enable/disable this feature.

Tried to improve the overall sound and found a way to improve digital sound output in favour of modulated sound. But the result is not very spectacular as the megadrive do not use sampled audio rarely. So only some intro audio and effects get improved (like collection of rings on sonic or pitfall title intro). I decided to drop the 2nd mod and use it on the SNES as this console uses more sampled audio output 

So now focus is on a better RGB output removing the glitches of the chipset and to implement the CRT emulation as well.

[retromod]

The components arrived the last days. The new surround mod seems to be complete now. There will be a run of 10 megadrive model 1 and 10 model 2 devices in the black/silver design with the following features:

- white box with manual and nice cover
- very good RGB output with CRT emulation (switchless)
- surround mod (worldwide unique, switchless), sound better than clear audio and all the other hacks.
- 50/60hz switch (switchless)
- multi region mod (switchless)
- new power supply and one controller (in new design)

not clear if a "freeze" function will be available via joystick so you are able to freeze the whole console and also disabling the screen/audio output (so a real pause mod preventing burn in).

[retromod]

The first consoles and components arrived yesterday.



I improved the RGB output a little bit and played around with the circuit of the console. Tested the CRT emulation mode but it seems it needs some additional work to make them compatible with the megadrive as it looks a little bit too bright.

[zapiy]

Look forward to seeing these completed. 

[Greyfox]

Yeah, so am I, some amazing mod tweaks in there I would say, these will problems be better looking than the original hardware, but that's a to order to fit, I think these MD mods are gonna sell really well IMO.

[retromod]

I completed the RGB mod. The Sega megadrive is a typical sample that there is always an improvement possible 

the stock RGB output lacks some sharpness and stable picture. Also have problems with some TV sets regarding sync signal. Finally I added my own RGB circuit and the picture can't be better. Crisp, right colors and no background noise or color rolling anymore. So with less than $5 you'll get a much better output than a stock megadrive. due to a clever trick the sync issue should be solved as well (requires some testing on different tv sets, my tv troublemakers have no issue anymore) together with the surround and audio mod a new audio experience, too.

next days I will check how to simplify and implement the switchless mod and also adding the CRT emulation for overall retro game experience. followed by some days to draw the final pcb.

hopefully I'm able to order the final PCB's end of this week and start to restore/prepare the first batch of mega drives.

[retromod]

Completed audio mod pcb which is now very small and perfectly fits into the console. I currently design the switchless mod and plan a generic PCB which can be used on other consoles as well. It will offer configuration and possibility to add more options later.

Console will be frozen and screen switched to a setup screen until you return to game by pushing reset button again. that provides a really cool and extendable method to deal with current and future config options. I also take into consideration to use a special controller button combination to activate that screen.

[retromod]

Video improvements completed. CRT emulation mode implemented and working well.


Picture taken with smartphone camera about 2 meters away from plasma screen (ignore the slightly mirroring)

Next step is to get a proper sync-signal logic implemented. the signal delivered by a factory console is bad and the composite signal add ghosting and all kind of noise to the video signal. I use a trick to use the pure sync signal delivering a quite better picture but this is not really compliant and may fail on different tv sets. so i will try to get a compliant solution here (will do that today).

I will also prepare the switchless mod and start programming tomorrow. I also decided to use SMD components if possible to lower the size of the board as MD2 has less room.

[zapiy]

That looks proper awesome..

[Shadowrunner]

That does look awesome, great start!

[retromod]

Finally fixed the common csync/sync issue and kept the picture quality 

Verified the single mods like console freeze and controller bypass which work as designed. Started with switchless mod by first implementing the composite menu, then rgb driven output. Good thing is that will be also used on other consoles as well (atari, coleco etc.) allowing to maximize functionality and options by preventing any additional hole or switch.

[retromod]

Working on the OSD option. Allows to output a menu on composite and RGB which makes it quite universal for all consoles. Final board will be SMD based to lower size and price tag.

[zapiy]

Fantastic. Look forward to seeing.