Looking for latest GEMS

For anything related to sound (YM2612, PSG, Z80, PCM...)

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r57shell
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Looking for latest GEMS

Post by r57shell » Thu Dec 27, 2012 11:50 pm

Ok, let's start.
I'm searching for GEMS devkits.
I spent few days already in google :D.
I've found only GEMS devkit for 2.1, and for 2.5.

But, nevermind. I want only latest possible version or best version of GEMS.
Where can I get it?) I see only one way: rip from some game, but...
I don't know which versions of GEMS used there.

BTW: How you think about creating some opensource toolkit for GEMS?
For example, something like: parser, tracker, merge, statistics(used/not used instruments, pcm...), jukebox, or may be something already exists?
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powerofrecall
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Post by powerofrecall » Fri Dec 28, 2012 1:48 am

I have GEMS 2.0 and 2.5 and I know it went up to at least 2.8. One neat thing included in those devkit zips that I've never seen anyone mention is the ROM for the Genesis side is included; it's GEMS.ABS. It's an s-record and can be converted to a flat binary with an s-record tool.

The changes between 2.0 and 2.5, at least, don't seem very significant. They are very different though than the very early versions of GEMS used in a few games. TaleSpin is one game that I can think of that uses an old GEMS (listen to sound effects playing with different musics; the sfx is locked to the music tempo).

There would be no point in making a tracker for GEMS because of the way it functions, from my understanding even the internal data format isn't really optimized when the stream is built, the Z80 program handles channel allocation and program changes on the fly. A lot of GEMS' internals seem to more or less map to MIDI CC's. This is both its greatest weakness and ironically its strength... it makes it easier to convert MIDI input into something the hardware can work with at the cost of being sloppy and unoptimized. Much easier on musicians. That said, a "midi2gems" type utility could be possibly feasible & I'd love to see it but not enough to scrape through the format myself. The source is all there in Z80.ASM though.

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TmEE co.(TM)
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Post by TmEE co.(TM) » Fri Dec 28, 2012 10:03 am

I got GEMS 2.8
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

r57shell
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Post by r57shell » Fri Dec 28, 2012 10:07 am

TmEE co.(TM) wrote:I got GEMS 2.8
I'm glad that you got it. But, where I can get it?) And, is it latest version?

About midi2gems - I don't know, but I wrote gems2midi -_-
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superjoebob
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Post by superjoebob » Thu Jan 03, 2013 2:21 am

I'm also fairly interested in this, I checked out the release on Hidden Palace (http://www.hidden-palace.org/?releases/44) but the link doesn't work!

I guess you'd need the hardware to do anything useful with it anyways? I'm assuming that's completely impossible to find.
On a never ending quest to compose for the Genesis/Megadrive

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Post by neologix » Thu Jan 03, 2013 4:49 am

Knowing Tiido he probably made his own hardware ;)

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TmEE co.(TM)
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Post by TmEE co.(TM) » Thu Jan 03, 2013 2:32 pm

Nope, I did not build a thing :P
I paid ~80usd for all the stuff and I still have not made anything too useful with them. The 256KB of RAM on the carts is cool though :)

http://www.tmeeco.eu/Fileden/GEMSstuff.jpg
http://www.tmeeco.eu/Fileden/GEMSworks.jpg
http://www.tmeeco.eu/BitShit/GEMS28.rar
http://www.tmeeco.eu/BitShit/DUMPS.rar

There we go !
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

r57shell
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Post by r57shell » Thu Jan 03, 2013 3:51 pm

Big thanks.

I did some research... I wrote some script on Perl to extract and compare dumps of GEMS z80 driver from romset. Only dumps - not asm.
So summary I have GEMS dumps from 1331 rom, it's from 214 different games. It's 27 different GEMS dump from games. Only z80 code - main driver.
Not all done yet. Many GEMS found but, exitst some troubles with extraction.

So in exchange I can upload log of tool: it's a rom name, start and end of GEMS code (main driver in z80), and in the end of log - grouped roms by identical GEMS driver :).
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Huge
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Post by Huge » Fri Jan 04, 2013 8:39 pm

TmEE co.(TM) wrote:Nope, I did not build a thing :P
I paid ~80usd for all the stuff and I still have not made anything too useful with them. The 256KB of RAM on the carts is cool though :)

http://www.tmeeco.eu/Fileden/GEMSstuff.jpg
http://www.tmeeco.eu/Fileden/GEMSworks.jpg
http://www.tmeeco.eu/BitShit/GEMS28.rar
http://www.tmeeco.eu/BitShit/DUMPS.rar

There we go !
Could you do some clean back/front photos of those dev carts?

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TmEE co.(TM)
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Post by TmEE co.(TM) » Fri Jan 04, 2013 8:58 pm

I'll sort out some urgent things first and fire up my scanner and do some scans !
Feel free to reming me !
Mida sa loed ? Nagunii aru ei saa ;)
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Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen

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Huge
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Post by Huge » Sat Jan 05, 2013 9:48 am

Hehe, I'll keep "reminging" you.

A scanner might not be the best choice though, as it gets out of focus on anything but whatever is the closest to the glass. I think it depends on scanner though.

I need to stop being lazy and start working on my own stuff, so I can set better examples on the kind of info I wish we had compiled on all these old sega stuff...

I've never seen that board on the upper right though. What is it? An EXT port to parallel interface??

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TmEE co.(TM)
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Post by TmEE co.(TM) » Sat Jan 05, 2013 1:07 pm

The scanner can scan your face at 50cm away with no problem. It is good stuff !

And I no longer have the EXT to LPT interface. I had to return it after making a schematic. It is basically nothing but a nibble exchanger (that works on all ports not just budirectional ones).
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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Huge
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Post by Huge » Sat Jan 05, 2013 6:17 pm

Scanning for so far is one thing, varying the focus on-the-fly is something different.... well, we'll see how it goes I guess.

Do you have any more pics of that interface? It says SEGA 1988 171-5734, right? I want to build a database of these things.

r57shell
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Post by r57shell » Sun Jul 21, 2013 11:39 pm

r57shell wrote:I did some research... I wrote some script on Perl to extract and compare dumps of GEMS z80 driver from romset. Only dumps - not asm.
So summary I have GEMS dumps from 1331 rom, it's from 214 different games. It's 27 different GEMS dump from games. Only z80 code - main driver.
Still not all done, but there is current results:
Log: http://pastebin.com/rt2yfD1Y
Graph of revisions: (weight calculated by xdelta patch count)
PNG: Image
SVG: http://elektropage.ru/r57shell/GEMS_xdelta.svg
PDF: http://elektropage.ru/r57shell/GEMS_xdelta.pdf

Edges between known driver version and some game means that drivers are equal.
I thought about doing same thing with disasm listening, but I don't know good z80 disassembler under win7 with console interface :)
I don't want to open each of 27 drivers in any GUI.
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Christuserloeser
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Post by Christuserloeser » Mon Jul 22, 2013 11:11 am

Wow, 214 different games using GEMS ... No wonder people thought YM2612 sounds bad :?
http://www.DCEvolution.net - Gigabytes of free Dreamcast software for you

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