Upcoming Sega MegaDrive modded consoles

[retromod]

yesterday I optimized the OSD firmware. To prevent using a bigger MCU for that (so keep it cheap)  it is required to deal with code and data size (like in the past) in a way both fits into the flashram.

Finally I decided to show only one option a time and you control via joystick to move on/activate it. similar to the sony crossbar. so less need for a full blown charset and complex drawings on the screen. it is really fun in trying to get the last bit out of the memory, specially as the mcu fulfill other jobs as well starting from control of the console to some video clippings to hide the typical megadrive vdp bug in RGB mode.

[zapiy]

Fantastic, when do you think you will tool up for this?

[retromod]

Fantastic, when do you think you will tool up for this?

The whole Sega Megadrive modding project will be completed within 2-3 weeks. I completed the RGB output mod, the CRT emulation mod, the Surround Audio mod (including much better sound and volume adjustment, too, stereo on SCART etc), the Sync mod (get rid of CSync/Sync issues) and have completed the proof of concept for 50/60, eng/jap, console halt (freeze the console immediately and continue) and the circuit for the OSD has also been completed.

I'm currently dealing with OSD firmware implementation/optimization which then feeds back to other consoles and I want to include the clipping mod as well. The clipping mod removes the noisy lines seen at the bottom of some consoles by using RGB. Those happens on some games/playfields and as I know it depends on the used VDP version. It is low hanging fruit but would be a nice to have. Why stopping at a 99% perfect system if you are able to easily reach 100%?  " title="Roll Eyes" />

I also look into possiblities in parallel to combine several mods like Stereo/Surround, OSD, CRT Emulation etc into one MCUU. But this is more longterm strategy to lower costs and simply production.

Next step is to redesign the PCB with SMD components which requires one day and sent to manufacturer. Schedule target is beginning/mid of february. Starting with ~20 mega drive 1 consoles in "25th Anniversary Edition" (prepared during waiting for the PCB's). Later with a simplified version also available via online configurator. there will be only one full blown mod as it makes no sense to split the mod's up as all of them uses functionality from each other.

[retromod]

There is one single bug in OSD firmware left: there is some flickering under certain conditions. A simple but may be time consuming bug which must be addressed.

But this will not delay the new board as the production requires about 1 1,2 weeks so plenty of time to fix this remaining issue.

As there are several video and audio signals to be switched I played around with the best (price/components) solution for it. Finally I dropped the "common" MOS related solution path and uses a slightly more expensive but less overheaded solution.

So it's now time to design the PCB board and place the order. Next fixing the flickering issue as this is only firmware related.

[retromod]

I completed all boards but sadly to say I failed the vacation time of china as new year celebration starts 18th most companies closed their doors.

So one week manufacturer delay! I will use the time to prepare as much as possible so assembly is faster later.

the whole mod consist of 3 PCB's plugged together. One for the surround system which is optional on later (cheaper) versions, one board for the sync and CRT emulation (optional later) and the mainboard containing the OSD, RGB part and all logic required to halt the console, control and manage it. the whole mod is about 6cm x 5cm x 1cm and really heavily integrated. I started several times to find the optimal arrangement for all parts.

Plan is to assemble 10 "25th anniversary version" of the megadrive I followed by a cheaper version of megadrive II models without some features. Currently working on the cover for the box and the manuals.
I also got brand new power supplies and controllers.

[zapiy]

This sounds awesome. Will you have a demo version to so either via images or a video?

[retromod]

i will create product videos and images of course.

[retromod]

This weekend I prepared 10+1 Sega Megadrive consoles. So if the new PCB's arrive it is only a small step until product is ready for shipping.


consoles fresh from storage


consoles after cleanup and refurbish of housing. added silver buttons/stripes.

[retromod]

Yesterday I refurbed the controllers now having 10 of them in really good shape.
The start button was painted in silver to match the design of the 25th anniversary edition.

I also found a small bug in the circuit of the mod which must be fixed by cutting one trace and solder an additional component.

[zapiy]

Great work. Look forward to seeing the finished product.

[retromod]

here the first prototyp of the box. currently working on manual, serial stickers, warning plates for power supply.
design might change for console itself as I plan to replace the "16 bit" by the "25 year" logo (same as on box).
Currently try out how to accomplish that in an easy way.

[retromod]

Tested possible new logo's. The 16-Bit logo will be replaced by the "25th year" logo. Here a test console with focus on different logo aspects.

It is still open if silver/black or black/white/silver. Depend on the upcoming ordered material.

[retromod]

First prototype of the box. The logo will be moved a few centimeters to the right but then production is ready.

[zapiy]

Honestly I am not to sure on the new badge!!!!

[retromod]

well the new logo has some big advantages:
1. most of the surfaces have scratches exactly on the 16-bit logo text
2. the 16-bit logo text is wiped out on most older consoles

adding the 25th logo will create a new shining surface on that location and it reflects "this console is something special". the final implementation will be most likely to be shorter so the small stripe with the LED is visible again (and shines in silver but is another single piece) which looks nicer as it provides more details.