megadrive/genesis -> video hardware/devkit/demo related questions

category: general [glöplog]

Just got the GBS at the end of the week, it works fine on my pc monitor.
I am waiting for the cables (I finally spent a bit more to get properly mounted cables, as it was 'cheap')
I may be abble to start to follow Pulko Mandy's guidelines on github to get it work synchronized.
I am also waiting the speedball 2 cartridge I could buy for almost nothing.
(I also looked the Chaos Engine one, which was...100€ !! what ??? :) ). I love bitmap brother's games.

Later, I will try to bring back to life an old cpc6128 with Gbs, the one I found in the street alone and crying, lost under the rain. lol
Unfortunately I couldn't bring the color screen with me but that's another story.

As I tried to explain precedently (trying is the right word, sorry it reads really weird !), your time is certainly counted PulkoMandy.
So, as I would appreciate support, I will start to figure out what's the content in your github by myself first.
Then go find what's necessary for my rpi2 if I can properly understand all of that.

Also, some links found in between posts,

Sega transfert suite's cable : https://www.retrodev.com/transfer.html (another 64k upload to ram possibility -so simple I wonder if it works-)
Actually I am wondering if learning with that cable wouldn't be a simple/ practical solution (for now) to test my garbage/lamer code on real hardware, then buy an everdrive later (and maybe usb this time, the most expensiv, but far away the most practical).
So any return from someone who had tested it, would be instructive..

In first post, I forgot the link for Chris Shrigley's webpage (official games source code) :
(easy to find though)

And a great source for documenting : http://info.sonicretro.org/

Due to the planet-d hosting problem, https://fra.planet-d.net/ is offline for now..

If anyone reading this post knows where I could find sporadic help with megadrive (asm) on IRC please tell me !
I highly consider learning by myself, but sometimes, you don't know what you don't know. ^^

added on the 2017-09-30 20:29:36 by nemka nemka
If you have a Pi2 you don't need any of my github sources. Follow the link to the forum where these things were first worked on, and somewhere in there you should find a link to a set of bash scripts for the Pi to drive the GBS8200.

I don't know how easy it is to setup, but the end result should be the same (since it's sending the same values I use with my devboard eventually).
yep, I'll do that, Thanks
added on the 2017-09-30 21:07:55 by nemka nemka
PulkoMandy, do you have by chance a scheme for the scart2vga cable please ?
I am looking for it.. it seems mine is badly soldered ! As my female scart/female scart was (what a mess :) )
added on the 2017-10-06 17:36:18 by nemka nemka
Nothing extraordinary in that cable:

scart pins 7, 11, 15: blue, green, red
pin 9: ground
pin 20: sync

VGA pins 3, 2, 1: blue, green, red
pin 9: ground
pin 13: sync

One last thing, I have following wire colors :

- blue
- large raw (not coverred by plastic)
- white
- brown (separated in 2 wires -> 0ne smallest brown one, one big brown one)

My question is about the brown one, is it used for color + Sync ?
Like small one for color and the bigger one for sync ?
Does the small brown wire stand for red color then ?

As delivered, this scart2vga cable would certainly have been used for a different purpose than mine. Wire weren't soldered the good pins.
added on the 2017-10-08 10:45:51 by nemka nemka