DS 16

For hardware talk only (please avoid ROM dumper stuff)
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KanedaFr
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DS 16

Post by KanedaFr » Tue Apr 18, 2017 10:29 pm

This "demo kiosk unit" was always a mystery to me.

At first, I think it was some sort of "5V line switch" but then I discovered it was connected throught the expansion port (same as MegaCD).
Image

why is it connected through the MCD port ?!
on the available doc, the cart is defined as a "slave cart" not as a main cart with logic which could load game
The only reason I saw was : the DS16 loading as main hw (for slave /cart to 1), loads the game on slave cart then reboot with slave /cart to 0
but a pic of the cart broke this idea (http://nintendoage.com/forum/messagevie ... did=141994) : no memory nor logic on pin 32
Image
so, again, if the DS16 redirect the selected cart pin to the Genny cart through the slave+cable, why on earth is it connected to the MCD port ?

I know the DS16 also include some kind of timer which switch the selected game every X (?) minutes but it doesn't explain it!
the DS16 is a rather complex as you can see on this assembler' thread
https://web.archive.org/web/20141104162 ... he-Genesis
(sorry, assembler seems to still be unavailable)
so what do you think it REALLY does, which could explain the MCD port use (and i really hope you won't say "because of the 9V lines")



On a side note, I saw a ferrite on (almost) every DS16 pics I found, over the DS16<->slave cart cable
How long could be the cable with a ferrite ? i though it was very bad idea to use this kind of cable (which runs the data and address lines it seems)...but not the real reason (noise?)
I ask because I'd like to do it on my dev unit but don't know if it won't create problem...

Mask of Destiny
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Re: DS 16

Post by Mask of Destiny » Tue Apr 18, 2017 11:24 pm

Well if you look at the cart slot PCB, it's clear that there aren't nearly enough pins on that ribbon cable for everything to be going through the cart slot. There are only 26 pins, but at a minimum you need 21 address lines, 16 data lines, !CE_0, !CAS_0, +5V and GND which is a total of 41 lines. So I suspect what is instead happening is that the DS16 primarily uses the signals available on the expansion port slot and is only using the cartridge to provide the missing signals.

Now why they did that rather than making something that fits in the cart slot exclusively is a bit of a mystery, but if I had to guess it's probably for mechanical reasons. Much easier to make a stable unit that gets a bunch of carts plugged into it if it's plugged in the side expansion port than delicately balanced on top. Also avoids issues with case redesigns.

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HardWareMan
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Re: DS 16

Post by HardWareMan » Wed Apr 19, 2017 3:25 am

Also it has no VD12-VD15. But it provide higher addresses and CE0. Also, it provides MRES and M3. So, basic signals it takes from EXT port, higher addresses and CE0 via this cartrige (that's why 244s need for) and able to MRES (more powerfull than VRES!) and M3. Simple and clever I think.

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