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Re: Epoch Cassette Vision and uPD77X chips [Re: seanriddle] #112219
01/18/18 02:21 PM
01/18/18 02:21 PM
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plgDavid Offline OP
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Awesome update, thanks. When you mean matching Kevtris's ROM dumps, that was for which type of chips? if its upD77X, given the procedure I could dump the rest of my cartridges.
Cheers

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112224
01/18/18 07:02 PM
01/18/18 07:02 PM
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ssj Offline
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Sean, did you ever check with Kevin if he is able to dump these electronically? I recall checking with him a few years back and iirc he hadn't tried it by then.

I recently sent a Hanimex HMG7900 machine and some games to PeT so he could have a look at it and the machine chip is from the same family (upD779C).

ECV games aren't particularly expensive so even if the dumping process ends up being destructive wouldn't be a big deal I think, I'd love to see this one emulated that's for sure. ECV, HMG-7900 and Gakken TV Boy are some tough nuts to crack.

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112225
01/18/18 10:55 PM
01/18/18 10:55 PM
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seanriddle Offline
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Turns out I had already Whinked the chip, so I took pics with the top metal removed. I also re-composited the top metal pics and created a larger die shot: https://seanriddledecap.blogspot.com/2018/01/blog-post.html

plgDavid- I decapped chips from some games that Kevtris had already electronically dumped so that I could figure out the physical location of the ROM bits. I used that information to visually dump Fabulous Fred's D557 and Computer Gin's D650. So I was hopeful that the ROM layout was the same in the D77x.

ssj- Not recently. A couple of years ago I sent him a Cassette Vision D777 that incog had sent to me.

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112245
01/20/18 09:16 AM
01/20/18 09:16 AM
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seanriddle Offline
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Unfortunately the D777 ROM is unlike any of the other NEC chips I've decapped. There are actually 2 ROM areas: a smaller one at top center with 50 rows of 114 bits, and a larger one across the bottom of the die with 64 rows of 360 bits. The smaller one has 7 columns of 16 bits and one column of 2 bits. The larger one has 24 columns alternating between 14 and 16 bits.

I transcribed both of them visually:
www.seanriddle.com/d777_1_raw.bin for the smaller one and

www.seanriddle.com/d777_2_raw.bin for the larger one.

Since 114 isn't divisible by 8, the first file has 50x15 bytes; each row has 6 bits of padding added to the end. I also rotated the 1st ROM array 180 degrees before transcribing so that the address decoding for the 2 ROM areas had the same orientation.

Because I dumped these visually, there are likely a few errors, so please double-check them

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112601
02/13/18 09:13 AM
02/13/18 09:13 AM
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ssj Offline
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Anyone managed to figure something out of the dumps?
The D777 is an all-in-one micro iirc as the console board doesn't have any video or audio hardware so maybe that would explain the 2 ROM areas.

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112604
02/13/18 02:29 PM
02/13/18 02:29 PM
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plgDavid Offline OP
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Hey Thanks Sean!
I just noticed this topic was updated.
Wow, that is some serious puzzle.

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112743
02/26/18 10:49 AM
02/26/18 10:49 AM
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Gilles Fétis Offline
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@ssj: for HMG7900-SD204 I think I sent you a dump of the 8049 2 years ago (this cartridge is based on a software "dumpable" 8049 clone).
but there may be a part of the 779 used for graphics or sound.

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112744
02/26/18 01:44 PM
02/26/18 01:44 PM
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incog Offline
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Is that from the early TV-Game, which also uses this chip, Epoch Space Invaders?

Last edited by incog; 02/26/18 01:45 PM.
Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112746
02/26/18 07:24 PM
02/26/18 07:24 PM
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Gilles Fétis Offline
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SD204 is https://www.youtube.com/watch?v=l82RbXcq6qA "racing turtle"... it's not a very great game and fixed volume speaker (preset to "loud") is awfull. This console is probably the lowest level of fun of all my collection. SD203 is a bit close to Epoch Space invader but in a reduced version (no shields)

Re: Epoch Cassette Vision and uPD77X chips [Re: plgDavid] #112747
02/27/18 12:39 AM
02/27/18 12:39 AM
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ssj Offline
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I recently sent the HMG 7900 console and some games to PeT to see if he could make something out of it, but he wasn't able to make any progress on it. Kevtris was interested to look at it at some point, but then got too busy. I think Sean will probably be able to dump the Motorolla micros based on what I spoke with him a couple years back, but without the 779 they won't be of much use.

Yes, I believe the 8049 will use the graphics and video from the 779 and iirc SlyDC came to that conclusion when he was reverse engineering the Cassette Vision and the HMG 7900. I think all the A/V stuff is done in the 779. Either way if someone figures out to emulate the Cassette Vision I'm sure HMG 7900 will likely be possible to emulate too.

I made that dump public back then, but don't think it ever got added to the softlists probably because there is no driver for the system.

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