USB MegaDrive DevKit

For hardware talk only (please avoid ROM dumper stuff)
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prophet36
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Post by prophet36 »

I don't know, I don't have a 32X to try it on. I don't remember the exact cycle-counts of the memory controller, and I'd rather not spend time messing with it now because I'll need to revisit it anyway when I move everything off the Nexys2 board (on which it is currently based) onto my own PCB which will use a different RAM chip.

The good news is I now have a GDB remote daemon working, so when I hit F11 in Eclipse, it runs the build and uploads the generated ELF binary to the MegaDrive over USB, and hits a breakpoint in main(). It's very cool to be able to step through the code running on a real MegaDrive. I'll make a video demo of it in the next few days and upload it to YouTube.
KRIKzz wrote:prophet36 i wonder if your memory controller enough fast for 32x?
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prophet36
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Post by prophet36 »

As promised:

Quick tour of the USB MegaDrive DevKit
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TmEE co.(TM)
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Post by TmEE co.(TM) »

that's pretty cool stuff :D
Mida sa loed ? Nagunii aru ei saa ;)
http://www.tmeeco.eu
Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen
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KanedaFr
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Post by KanedaFr »

Hmmmmmmm.... didn't know about this GDB serial debugging...
I was about to make something similar (porting KDebug to use port 3 of the MD1) and ordered a serial to USB board 2 days ago !!
I now see something else to do with this board ;)

anyway, your work is just AWESOME ! Congratulations on this!
Last edited by KanedaFr on Sat Jul 02, 2011 11:56 pm, edited 1 time in total.
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prophet36
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Post by prophet36 »

Thanks!

Actually I was surprised too. The GDB remote protocol is very simple, and you can get away with only implementing a small subset of the protocol. In my case I implement the protocol on the PC side, and have it forward requests over a custom USB protocol to trigger actions either in the FPGA or in the 0.4KiB monitor program that runs on the MD. But you could implement the whole protocol easily enough entirely on the MD side, provided you have some kind of bidirectional port on the MD side.

I made a few changes to GDB to make it use Motorola format (and drop the %-prefixes for registers) for the disassembly. The code for those diffs is here.

I will update the UMDKv2 repository in the next few days; hopefully you'll find my remote protocol implementation useful as a starting point.

Next thing for me is to debug my VHDL SD-card interface and its 68000 driver! And at some point I need to start laying out the final PCB...
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doragasu
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Post by doragasu »

This is really neat. I would love having a tool like this!

If this could be produced using a cheap FPGA, I would surely buy one (or build it myself).
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MintyTheCat
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Post by MintyTheCat »

doragasu wrote:This is really neat. I would love having a tool like this!

If this could be produced using a cheap FPGA, I would surely buy one (or build it myself).
It is one of the most useful things to be seen in the MD Dev Scene since the start I'd say. He needs the support of the community to finish it.
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KanedaFr
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Post by KanedaFr »

I don't exactly remember but I think he moved to something else...
He more or less learnt FPGA with this project ....
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MintyTheCat
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Post by MintyTheCat »

KanedaFr wrote:I don't exactly remember but I think he moved to something else...
He more or less learnt FPGA with this project ....
He's working on a number of Projects such as FPGALink - the MD received less interest so it is a lower priority - er..... Community!!!!!
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bastien
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Post by bastien »

Hi , i have just a question about custom megadrive cart builing.
I want to make a PCB with a 0,6mm for route track.
is-it ok for the console ?
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MintyTheCat
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Post by MintyTheCat »

bastien wrote:Hi , i have just a question about custom megadrive cart builing.
I want to make a PCB with a 0,6mm for route track.
is-it ok for the console ?
I'd try asking that in the Hardware Section and not in this Thread.
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Teancum
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Post by Teancum »

Looks like the repository has been updated as recently as 3 months ago. Hope to see an update on this soon.
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MintyTheCat
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Post by MintyTheCat »

Teancum wrote:Looks like the repository has been updated as recently as 3 months ago. Hope to see an update on this soon.
He has been busy:

http://www.youtube.com/watch?v=iett8oM92J0
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KanedaFr
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Post by KanedaFr »

OK, so now I have to convince Prophet to selling some of us (me included) his dev kit ;)

edit : just watched the vimeo video...is it Linux only (umdk) ?
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MintyTheCat
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Post by MintyTheCat »

KanedaFr wrote:OK, so now I have to convince Prophet to selling some of us (me included) his dev kit ;)

edit : just watched the vimeo video...is it Linux only (umdk) ?
It is not 'Linux only' but many of the Tools are UNIX Tools.

Come on, kaneda, are you looking for reasons not to use it or what?
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