schematic DSP-1, DSP-2, DSP-3, DSP-4

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Kayumba
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schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Sun Mar 21, 2021 11:09 am

Hi,
Can somebody please share schematic for cart :
DSP-1, DSP-2, DSP-3, DSP-4

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Fisher
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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Tue Mar 23, 2021 6:34 am

A while ago I tried to add battery backup to a pirate Mario Kart and this is what I ended with:
https://drive.google.com/folderview?id= ... TVMMjJpLVU

Probably the battery circuit is not correct, the other parts needs to be checked but I think it's mostly fine.
Any corrections and additions are welcome.

Hope it helps.

Kayumba
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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Tue Mar 23, 2021 4:02 pm

Fisher wrote:
Tue Mar 23, 2021 6:34 am
A while ago I tried to add battery backup to a pirate Mario Kart and this is what I ended with:
https://drive.google.com/folderview?id= ... TVMMjJpLVU

Probably the battery circuit is not correct, the other parts needs to be checked but I think it's mostly fine.
Any corrections and additions are welcome.

Hope it helps.
Hi Fisher,
Yeah , I already saw your pictures ;)
Thank you for sharing with us your project.

I don’t know if there is some equivalent chip to remplace DSP chips?
The price on Aliexpress of original DSP chips is about 10€ For one !
So its become not intresting to do it.

About schematic circuit of DSP games :
I got one original cartridge on Mario Kart at home, I can beep every circuit and see all connections but I thought maybe it’s exist already somewhere.

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by calima » Wed Mar 24, 2021 1:03 am

No, I don't think DSP clone chips exist.

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Fisher
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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Wed Mar 24, 2021 2:07 am

A while ago I saw some "blank" upd77p25d for sale on Aliexpress. I've heard that they're common on some kinds os semaphors.
Unfortunatelly I don't know how ro write these chips neither what files should be used.

There are rumors that the firmware was dumped and is used on Higan (or BSNES?), but I'm not sure if these files can be written as-is to the chip, since they seem to have been obtained by decapping.
But I can be totally wrong and would love to be corrected and learn how to write these chips. :-)

calima wrote:
Wed Mar 24, 2021 1:03 am
No, I don't think DSP clone chips exist.
Yes, they do.
SNES Central has a small article talking about it.
If you take a look at the pictures I shared you'll see that the DSP1 chip used on my pirate carttidge is also a clone with some weird issues that disconnecting some pins seems to have fixed it. :shock:

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Wed Mar 24, 2021 2:56 am

Fisher wrote:
Wed Mar 24, 2021 2:07 am
A while ago I saw some "blank" upd77p25d for sale on Aliexpress. I've heard that they're common on some kinds os semaphors.
Unfortunatelly I don't know how ro write these chips neither what files should be used.

There are rumors that the firmware was dumped and is used on Higan (or BSNES?), but I'm not sure if these files can be written as-is to the chip, since they seem to have been obtained by decapping.
But I can be totally wrong and would love to be corrected and learn how to write these chips. :-)

calima wrote:
Wed Mar 24, 2021 1:03 am
No, I don't think DSP clone chips exist.
Yes, they do.
SNES Central has a small article talking about it.
If you take a look at the pictures I shared you'll see that the DSP1 chip used on my pirate carttidge is also a clone with some weird issues that disconnecting some pins seems to have fixed it. :shock:
OMG !
If upd77p25d must be programed before ...
Anyway upd77p25d chip still cost very expensive (for me).
For few games that exist with those chips, it's became not interesting to do it.

I found some info here,
guys made some emulation with dumped files of DSP chips.
https://forums.bannister.org/ubbthreads ... 1&page=all

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Fisher
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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Wed Mar 24, 2021 3:34 am

WOW!
I took a look at Aliexpress and the price is WAY bigger than before. :shock:
Fortunatelly EBay seems to have better prices, but not as low as it was.

If I understood correctly the datasheet, the chip should be written just as an ordinary EPROM.
Is it correct?

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Wed Mar 24, 2021 3:52 am

Fisher wrote:
Wed Mar 24, 2021 3:34 am
WOW!
I took a look at Aliexpress and the price is WAY bigger than before. :shock:
Fortunatelly EBay seems to have better prices, but not as low as it was.

If I understood correctly the datasheet, the chip should be written just as an ordinary EPROM.
Is it correct?
Dont know about how to program them.
Have to read more about that.

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Wed Mar 24, 2021 4:04 am

I forgot to post the datasheet.
Page 29 describes the programming process.
Seems pretty similar to a EPROM to me, maybe with some pins swapped.
Attachments
UPD77P25D.pdf
(1.46 MiB) Downloaded 20 times

Kayumba
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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Wed Mar 24, 2021 4:48 am

Fisher wrote:
Wed Mar 24, 2021 4:04 am
I forgot to post the datasheet.
Page 29 describes the programming process.
Seems pretty similar to a EPROM to me, maybe with some pins swapped.
now rest to to find dumped files of DSP chips and make some thousand of tests :roll:

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Wed Mar 24, 2021 4:57 am

Looks like Caitsith2 has dumped then and posted here.
Please, keep us updated with your DSP "adventures". :wink:

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Wed Mar 24, 2021 5:40 am

Fisher wrote:
Wed Mar 24, 2021 4:57 am
Looks like Caitsith2 has dumped then and posted here.
Please, keep us updated with your DSP "adventures". :wink:
Great !
Thank you for links.
Yeah, I will keep you update if I will progress :lol:

I found uPD77C25C on eBay for good price, but not sure if its can be erased :
https://www.ebay.fr/itm/10pcs-UPD77C25C ... 4965123429

And on Aliexpress uPD77P25D.
Look's like this one can be erasable like any EPROM:
https://fr.aliexpress.com/item/10050012 ... web201603_

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Wed Mar 24, 2021 7:06 am

The datasheet states that the windowless versions are OTP, the only version being able to be reprogrammed is the windowed one.
It's eraseable with exposure to ultraviolet light with an wavelength shortrt than 400nm, 250nm typical and a power of 1200 μW/cm2, pretty much the same way as an EPROM.
Unless there's a newer version wich supports flash, but I'm not sure if this exists.

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Kayumba » Wed Mar 24, 2021 8:34 am

Fisher wrote:
Wed Mar 24, 2021 7:06 am
The datasheet states that the windowless versions are OTP, the only version being able to be reprogrammed is the windowed one.
It's eraseable with exposure to ultraviolet light with an wavelength shortrt than 400nm, 250nm typical and a power of 1200 μW/cm2, pretty much the same way as an EPROM.
Unless there's a newer version wich supports flash, but I'm not sure if this exists.
Thanks for info.
I didn't find on eBay windowless versions, only on Ali.

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Re: schematic DSP-1, DSP-2, DSP-3, DSP-4

Post by Fisher » Fri Mar 26, 2021 9:18 am

I think the eraseable windowed ones are the way to go, at least until you know exactly what an how to write it. :wink:

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