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Game Gear prototype/samples cartridges photos/scans (Was: Request: Game Gear Prototype Cart scans)
Posted: Sat Jan 08, 2011 8:32 pm Last edited by Snow_Cat on Sun Jan 23, 2011 6:10 pm; edited 2 times in total |
Hello;
I've been assistng Gary_Man with his GameGear dev cart project, and I would like to reproduce the original board arts however, lacking an actual cartridge to study need your help.
These are the initial traces of the 1990 171-5986B 1M/256K ROM +RAM board I drew last night. These are based on images taken from http://devkits.handheldmuseum.net/, http://lostlevels.org/, and an ecco the dolphin fan site (the domain of which is now a [spamword] site). As you can see there are some gaps were the boards were populated and I need to figure out where those wires go, but given the pinouts this shouldn't be a problem. I'll get around to porting this into Eagle or KiCad in a couple of weeks. edit: images moved from external host to attachements. edit: images moved from attachments to external host edit: added host name/warning to image link I cannot do the same for the 1992 171-6305B board however, as I have not found an image of this with the component markings clear enough to identify. I believe that those were designed for 512K/.../4M ROM +RAM, and had a square top bit, roughly twice the size of a regular cartridge and was mostly populated with surface mount components. There was probabally a ?/32M version later, but I've no specifics data for it. If someone could bring me a high resolution scan of the board (populated or not) I should be able to produce an accurate 1:1 reproduction of the original board art. (Also; I am not a spam bot) |
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(Lack of) progress update
Posted: Sat Jan 15, 2011 10:56 pm Last edited by Snow_Cat on Sun Jan 23, 2011 6:04 pm; edited 1 time in total |
The eagle files got corrupted while I was working out the connections of the multplexor. I likely won't be reverting to an earlier version and continuing this clone since there does not seem to be any intrest in it.
Remarks (correct me where I am wrong but I think...) It appears that either the multiplexor controlls the output enable and upper address lines, while the pager(IC4) controls the chip enable signals independantly; or the multiplexor controls the configuration of IC4(25,27,28) and the chip enables of ROM(IC1); though this seems much less likely.
(Note, line 16 of the pager enables IC2-ROM chip in this configuration, and two address lines are not connected) Has the configuration of the mapper chip been documented, and is the datasheet of the voltage supervisor (Microchip 1026B) availble? Or would implementing a 'fresh' 74xxx board with support for larger memories be prefered? edit: attachments moved to external host. |
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Posted: Sun Jan 16, 2011 2:13 am |
I should be able to provide you detailed pictures in April. | |
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Posted: Sun Jan 16, 2011 5:32 am |
Thanks;
though you don't need to hand deliver the pictures in person. If there are any other pcbs already scanned with the same mapper I could try and determine the chip configuration/wiring from those. |
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Posted: Sun Jan 23, 2011 7:25 pm |
I now have a copy of much more complete and detailed Memory mapper hardware notes by Charles MacDonald hosted at cgfm2.emuviews.com, and a youtube video Gerry_MAN found of the board.
I will be updating the Eagle library and comparing it against this dev-board to check it's consistency. |
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SEGA's Prototype GG cart
Posted: Sun Jan 23, 2011 7:59 pm
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Hi Bock,
If you're actually going to be getting your hands on one of these official SEGA DEV carts, depending it might have an EPROM chip installed with it that holds a GG system diagnostics program made by SEGA programmers. I think a lot of these units were used for the purpose of testing custom games during development of course, but also for testing the GG systems themselves. It would be amazing to get a copy of this Diagnostics ROM image off the EPROM. I'm sure by having all of the Code gurus here take a look at the code....it might reveal new things about the GG hardware. It just made me really curious and want to check it out. As described in the Youtube video by AssemblerEX he talks about the diagnostic test program on the EPROM. http://www.youtube.com/watch?v=axWvKighZ50 Anyhow, if by chance you get your hands on a similar diagnostic EPROM.... if you could download the image and post it for us to check out that would be amazing. Plus it would just be great to add to the global ROM collection out there. I've made several attempts and asked AssemblerEX if he could share this ROM image, but to this point he has not responded. It could be that he doesn't have an EPROM reader or doesn't know how to do this. It could also be that he just has no desire to. :( In any case, I think it would be really interesting to check out. Regards, -Gerry |
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Posted: Sun Jan 23, 2011 9:57 pm |
The video is only of the cart so no real help in knowing what the software is doing. | |
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Re:Request: Sega's Prototype Cart scans.
Posted: Sun Jan 23, 2011 10:17 pm
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Hi Maxim,
Yeah this is true. However, do you think that if we did manage to acquire this Diagnostics Image, and analyzing its code, could possibly shed light on certain functions of the GG? Or do you think it would only show things already known? -Gerry |
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Posted: Sun Jan 23, 2011 11:52 pm |
I'll include a Game Gear slot in the papercraft library so to make dumping these easier. Also, I've updated the Eagle Library- the component list has not been significantly expanded however the descriptions for some of the existing components are now morecomplete. the 315-5235 for example now includes the pin and signal descriptions for 4M mode usage.
edit: sorry, Google has been taking the piss since I uploaded this file: docs.google.com HPFix.zip - it allows users to print with an HP printer using HP ink on a HP (windows) desktop more than a year after purchase. Also works with third party ink refills, and other windows machines. The links should never have demanded a login for access. |
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Posted: Mon Jan 24, 2011 9:10 am |
It's likely to contain: - checks of RAM, VRAM etc (can I write something and read it back) - maybe some interactive tests (exercise the VDP/controllers in obvious ways) - maybe some CPU sanity checks (Although if that is screwed, how's the test going to run?) - maybe some stuff to do with the development hardware. We already know a fair amount from the official docs, but it's of little interest as it's not really useful to us. |
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Posted: Mon Jan 24, 2011 1:55 pm |
So then it's down to having it strictly for the sake of collecting!
Well It sounds interesting and I'd still like to check it out regardless. Thanks Maxim. -Gerry |
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Posted: Mon Jan 24, 2011 7:21 pm |
I can imagine the discovery of Sega's initilization for some graphics mode not used in actual games, or finding parts of other files from the dev machine carelessly burnt onto the ROM.
Neither of which are particularly useful, but I would be entertained by someone hacking together the details. Gerry, once I have the papercraft instructions complete, would you be wililng to test the GG slot component? edit: punctuation mark. |
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Posted: Mon Jan 24, 2011 8:01 pm |
Sure, I can do that. :) | |
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Posted: Wed Feb 02, 2011 5:56 am |
I have found (more) complete schematics at ~haf09260 www2.odn.ne.jpEnri's Home Page and will try cloning from these some time this week.
Also, My initial papercraft experiments have found that using stranded (ide) cables is far too prone to failure. If it doesn't break while striping, then it frays while threading, if it doesn't fray while threading then it is tearing while stitching. Another week while I try again using scrap network cables, with solid cores the later two problems should be less apparent. |
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Posted: Wed Feb 09, 2011 4:52 am |
I've done a prototype of the GG-papercraft component;
I will have to make an ilustrated guide later.
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Game Gear 171-5986B boards
Posted: Thu Mar 26, 2015 1:02 pm
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Attached a bulk of pictures of the Game Gear prototype 171-5986B boards.
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Game Gear 171-6305B boards
Posted: Thu Mar 26, 2015 1:10 pm
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Attached a bulk of pictures of the Game Gear prototype 171-6305B boards.
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GG DEV Carts
Posted: Thu Mar 26, 2015 2:49 pm
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Hi Bock,
Nice collection!! Very cool. -Gerry |
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Posted: Fri Mar 27, 2015 8:47 pm |
Thanks, and a few days before April (2015) even!
It has been so long that I have lost familiarity with my old project files but I should be able to produce new CAD files for an accurate reproduction board if there is any intrest. |
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Posted: Wed Apr 15, 2015 10:19 am |
Attached close up pictures of a 171-5986B board.
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Official SEGA DEV Cart clone
Posted: Mon Jun 08, 2015 1:31 am
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Hi Snow_Cat, It's been a while.... :)) We've all been busy with regular life getting in the way it seems. I'm working for a new company as an Electronics debugging Technician and I have access to a PCB XRAY machine. I was thinking I could take a few scans of my Official SEGA DEV cart and send them to you. You could probably use them to map out the proper trace paths. You might have to use your own judgement...... as some traces can sometimes be faint. It would be awesome to get a full clone of one of these Badboys. :)) Your thoughts? -Gerry |
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Megaman sample, CAD-TEAM/Capcom? GG board
Posted: Mon May 01, 2017 9:19 am
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EPROM:
US Gold ROM: Megaman Date: 10/23/95 Board: (c) Sega 1995 Made in Japan 171-7101A CSPD CAD-TEAM It's currently on eBay for a stupid price ($7999) http://www.ebay.com/itm/272652334022?ul_noapp=true&autorefresh=true Presumably someone will end up snatching it for a 3 digit price. Because of the date it is probably a final build. |
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