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Can I use a TSOP to make 8 megabit LoRom repros? (SNES)
https://forums.nesdev.com/viewtopic.php?f=28&t=12377
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Author:  nepharax [ Fri Feb 13, 2015 9:39 am ]
Post subject:  Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

Hi all, I'm new here - but I've been reading up on how to create repros.

I understand that you can use an 29f032 to make larger games, but what if I want to use a 16Megabit TSOP (16 Mbit (2Mbx8)) to make an 8 megabit game?

I acquired 10 29f016b chips and I'd like to use them for that purpose.

In addition, from what I can tell - the 8 Mb cartridge boards MASKROM only has 32 pins whereas a larger game MASKROM has 36 pins.

The DIP36-TSOP40 adapters I have (adapter III) have more pins (4) than these 8 megabit boards have. Is there any documentation or advice anyone could offer on what I'd need to do to use the 36-pin TSOP board on a 32-pin board?

Appreciate any help with this.

Thanks!

Author:  lidnariq [ Fri Feb 13, 2015 1:50 pm ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

nepharax wrote:
I understand that you can use an 29f032 to make larger games, but what if I want to use a 16Megabit TSOP (16 Mbit (2Mbx8)) to make an 8 megabit game?
Either duplicate the 1MiB of data (e.g. copy /b 1MB.BIN+1MB.BIN 2MB.BIN), or tie the EEPROM's A20 line to Vcc or Gnd.
Quote:
In addition, from what I can tell - the 8 Mb cartridge boards MASKROM only has 32 pins whereas a larger game MASKROM has 36 pins.
8Mbit = 1 Mbyte.
1 Mbyte → 8 data lines + 2 power lines + 2 control lines + 20 address lines = 32 pins
Quote:
The DIP36-TSOP40 adapters I have (adapter III) have more pins (4) than these 8 megabit boards have. Is there any documentation or advice anyone could offer on what I'd need to do to use the 36-pin TSOP board on a 32-pin board?
Look up the datasheets for the parts. In general, all inputs need to be connected to something, either an address line or power or ground.

Author:  MaarioS [ Fri Feb 13, 2015 5:05 pm ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

Basically the TSOP40-DIP36 adapter was intended to use for SNES so the pinout is the same as mask ROMs on the board. It looks exactly like this:
Image

Well in your case if you're using 29F016, it looks more like this:
Image

So if you want to use it as 1MB chip on a 32pin socket, I'd suggest this solution:
1.Double 1MB image to get 2MB in total
2.Program your chip like normal, just put it in the adapter, choose 29F016 and write the image
3.After you program it, remove 4 upper legs from the chip (pins 1,2, 35 & 36)
4.Connect the legs as shown in the picture (just connect pins 1, 34, 35 & 36 together)
Image

Author:  nepharax [ Sat Feb 14, 2015 5:55 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

Thank you both for your detailed responses.

Here's the data sheet on these particular chips.

http://pccomponents.com/datasheets/ST-M29F016B.PDF

The pinout looks different from the one for the other 29F016.

Author:  MaarioS [ Sat Feb 14, 2015 10:13 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

The pinout of your memory matches mine so the above instructions I provided to you should do the job

Author:  nepharax [ Mon Feb 16, 2015 8:12 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

MaarioS wrote:
The pinout of your memory matches mine so the above instructions I provided to you should do the job


How do you figure? I compared it and I only see 3 similar pinouts between the two. Am I looking at it wrong?

Image

Author:  MaarioS [ Mon Feb 16, 2015 8:30 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

What I showed you above is actually not the pinout of your TSOP memory but rather pinout of that TSOP->DIP adapter and it presents the final rearranged DIP36 pinout. This is the entire point of this- adapter, it's supposed to rearrange the pins from memory to specific places where SNES expects them. If you don't really understand what I just said and you don't believe it- analyze the traces on this adapter, you'll confirm what I said

Or to put it simple: THIS is what you provided the pinout for:
http://i.imgur.com/cgjkhrf.jpg
and THIS is what I provided the pinout for:
http://i.imgur.com/RVFg4n6.jpg
Ah and by the way, in case you didn't know, remember to strap these pins:
http://i.imgur.com/aP7OWHv.jpg

Author:  nepharax [ Mon Feb 16, 2015 9:18 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

Oh ok, I get you now. Sorry about that - I was confused by the pinout.

Thanks for your help!

Is this correct according to your layout?

Image

Author:  MaarioS [ Mon Feb 16, 2015 9:39 am ]
Post subject:  Re: Can I use a TSOP to make 8 megabit LoRom repros? (SNES)

Exactly, this is the correct way

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