Changing BIOS ROM on Twin Famicom?

[boye]

I'm planning to get a Sharp Twin Famicom in the near future, but the Famicom logo in the FDS bios feels kinda odd. Is it possible to rplace the BIOS ROM in the Twin Fami? I'm going to get the AN-505-BK if that helps.

[adori_12]

I've seen some Japanese guys making videos about Faulty Twin Famicoms, and sometimes they just swap the disk drive of a working standalone FDS and use that on a Twin, getting the Nintendo branded logo you want on a Twin Famicom.
The drives are completely interchangeable, so just go ahead and do that.

[zmaster18]

You could maybe be do this by desoldering all the similar chips you see on the Twin and replace them with similar chips on the RAM adapter.

Putting a drive from an FDS in a Twin does not change the logo on the BIOS.

[80sFREAK]

BIOS ROM hiding in 2C33 chip. Replace it with one from regular FDS... if you can 

[boye]

Does anyone have a pic of the  AN-505 board?
(And yes, I know it's essentially a Famicom with a Disk System bolted on.)

[adori_12]

Putting a drive from an FDS in a Twin does not change the logo on the BIOS.

So where in the main boards is the BIOS ROM located in? 

[P]

80sFREAK just told you:

BIOS ROM hiding in 2C33 chip.

Which is in the RAM adapter part, not the disk drive part (remember you can start the FDS screen without the disk drive).

[adori_12]

80sFREAK just told you:

Sorry, I meant where in the Twin Famicom is the BIOS ROM, since there is no external RAM adapter on a Twin.

[jpx72]

Just google a bit!
https://console5.com/wiki/Twin_Famicom
Look for IC109..... it's the big one on top in the picture.

[P]

Yeah the RAM adapter is still a separate part from the drive in the Twin. The 2C33 chip is still there (written with prefix and possibly a suffix as in that picture).