Famicom World

Family Computer => Technical & Repair Assistance => Topic started by: boye on June 06, 2019, 06:57:57 pm

Title: Changing BIOS ROM on Twin Famicom?
Post by: boye on June 06, 2019, 06:57:57 pm
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.
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: adori_12 on June 07, 2019, 01:19:38 am
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.
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: zmaster18 on June 07, 2019, 03:21:33 am
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.
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: 80sFREAK on June 07, 2019, 06:13:27 am
BIOS ROM hiding in 2C33 chip. Replace it with one from regular FDS... if you can  ::)
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: boye on June 07, 2019, 10:25:45 am
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.)
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: adori_12 on June 08, 2019, 12:09:18 pm
Quote from: zmaster18 on June 07, 2019, 03:21:33 am
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? 
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: P on June 08, 2019, 01:28:13 pm
80sFREAK just told you:
Quote from: 80sFREAK on June 07, 2019, 06:13:27 am
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).
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: adori_12 on June 12, 2019, 07:57:58 pm
Quote from: P on June 08, 2019, 01:28:13 pm
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.
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: jpx72 on June 12, 2019, 11:15:09 pm
Just google a bit!
https://console5.com/wiki/Twin_Famicom
Look for IC109..... it's the big one on top in the picture.
Title: Re: Changing BIOS ROM on Twin Famicom?
Post by: P on June 13, 2019, 05:01:28 am
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).