What's new

Kujako

Grand Master
Joined
Jun 3, 2020
Messages
1,327
Reaction score
786
Location
USA, California
Anyone know of a good guide to parts for making SOP 40/44 UniBIOS chips for MVS MV1B and MV1C boards? I've been just getting them from aliexpress, but thinking I should start making my own.
 
Expanding on this... I think the MV1C can use a R27V6402G SOP44 but I'd like confirmation since it's 4MB and ~3.3v. Not sure what the MV1B uses, but they're not interchangeable from my experience. The replacements from aliexpress use a clearly sanded and relabeled chip for the 1B (SP-S3) and for the 1C they use an obfuscated (partial sanding of the label) Toshiba chip. Looking to try and figure out what these are, so I can order in bulk and make my own. Ideally looking for a compatible 1MB SOP40 at 5v (or maybe 3v is fine, no clue).

1707493579506.jpeg


1707493614309.jpeg
 
Last edited:
I didn't know anyone ever bothered. Just get a "BiosMasta." The imitations on ebay are cheap -- just search for "neobiosmasta"
 
I didn't know anyone ever bothered. Just get a "BiosMasta." The imitations on ebay are cheap -- just search for "neobiosmasta"

I have several, I prefer to replace the chip as my experience with them hasn't been ideal (keeping them secured in place seems to be an ongoing issue). But I get the appeal and agree they are a good option, but for how cheap the replacement pre-flashed chips are I find it easier to go that route, especially since I tend to just remove the stock BIOS when going the Bios Masta route.

Edit: having said that, I'll be installing a Neo BiosMasta this weekend since it looks like one of the pads on this MV1B is damaged. I'm far too lazy to run a new trace and looks like I've got one of the good red/white ones left.
1707513044184.jpeg


@Neo-Alec do you use hot glue when attaching these? Even with I've had them pop off at inopportune times...
 
Last edited:
I think that a MX29F1610 does the trick... 1M word*16 or 2M byte*8 5v read/write. It's 44 pin, but we can ignore the extra 4 from the look of things.

1707513685744.png
vs
1707513805516.png
used by SNK.

Not clear why the MV1B and MV1C act differently, but I've mistakenly used a MV1C UniBIOS chip on a MV1B and it didn't post and the ones from aliexpress are clearly different. But will order some and see what I can figure out...
 
I have several, I prefer to replace the chip as my experience with them hasn't been ideal (keeping them secured in place seems to be an ongoing issue). But I get the appeal and agree they are a good option, but for how cheap the replacement pre-flashed chips are I find it easier to go that route, especially since I tend to just remove the stock BIOS when going the Bios Masta route.

Edit: having said that, I'll be installing a Neo BiosMasta this weekend since it looks like one of the pads on this MV1B is damaged. I'm far too lazy to run a new trace and looks like I've got one of the good red/white ones left.
1707513044184.jpeg


@Neo-Alec do you use hot glue when attaching these? Even with I've had them pop off at inopportune times...
No, never needed hot glue. I wouldn't expect that to really help.

How are they popping off? During transport?
 
No, never needed hot glue. I wouldn't expect that to really help.

How are they popping off? During transport?

Transport or even storage. Granted, most of the problematic ones are third party. The original ones like the red one I pictured seem far less problematic.
 
Transport or even storage. Granted, most of the problematic ones are third party. The original ones like the red one I pictured seem far less problematic.
I see. Sounds like a problem with the connector on the third party ones. In my experience with the originals, there's no reason they should come off in storage. I haven't even had a NeoTurfMasta one pop off for any other reason either.
 
Back
Top