[Tech] Rainbow Islands roms

[guddler]

[ukvac] [Tech] Rainbow Islands roms
Hi,

IC23 and 24 on a Rainbow Islands that I have for someone here are
'custom' Taito chips. They are labelled B22-03 & B22-04, which according
to the mame driver (and my best guess too), these just look like roms.

The mame code suggests they are in the order of 8*128 (ri_m03/4.rom) and
the board is marked '23C1000'.

As I can't find any reference to 23C1000 in my device list or the chip
dir, anyone have any idea what device I should use to dump these two? I
have tried 27C1000, but got pretty uninspiring results.

TIA,
Guddler.

 

[PaulSwan]

Re: [ukvac] [Tech] Rainbow Islands roms
Gud,

Are these 28-pin 128K MASK ROMS? There is no equivalent EPROM pinout.

You can read them as two 27C512 by manually tieing the OE pin high for
one read and low for the other (bending the pin out of the programmer
socket).

You can replace them with a 27C100 with the alternate pinout. These are
32-pin so you have to strap the upper 4 pins that dangle out of the
socket. I've done this once to fix a broken ROM on an NZ story.

My programmer has two options for 27C100, it has a "27C100 (EPROM)" and
"27C100 (MASK)". The latter is for reading these 28-pin versions. Check
that first. You can also try 27C100 and see if it works anyway

Regards,

Paul.

Guddler wrote:
>
> Hi,
>
> IC23 and 24 on a Rainbow Islands that I have for someone here are
> 'custom' Taito chips. They are labelled B22-03 & B22-04, which according
> to the mame driver (and my best guess too), these just look like roms.
>
> The mame code suggests they are in the order of 8*128 (ri_m03/4.rom) and
> the board is marked '23C1000'.
>
> As I can't find any reference to 23C1000 in my device list or the chip
> dir, anyone have any idea what device I should use to dump these two? I
> have tried 27C1000, but got pretty uninspiring results.
>
> TIA,
> Guddler.
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

 

[guddler]

RE: [ukvac] [Tech] Rainbow Islands roms
> Gud,
>
> Are these 28-pin 128K MASK ROMS? There is no equivalent EPROM pinout.
>
> You can read them as two 27C512 by manually tieing the OE pin
> high for one read and low for the other (bending the pin out
> of the programmer socket).

They appear to be mask roms, so I dumped the first half by just using
the 27512 device setting and this looks the same as the first half of
the mame rom, but when I bend pin 22 out of the programmer to get the
next half I get the same dump again.

Am I doing something wrong?

Guddler.

 

[PaulSwan]

Re: [ukvac] [Tech] Rainbow Islands roms
Gud,

Need to tie the pin to +5V on one read and GND on the other to get the
two halves.

Paul.

> I get the same dump again.
>
> Am I doing something wrong?
>
> Guddler.

 

[guddler]

RE: [ukvac] [Tech] Rainbow Islands roms
Oh!, okay, cool - got it, and it checks out fine - thanks...

> Gud,
>
> Need to tie the pin to +5V on one read and GND on the other
> to get the two halves.
>
> Paul.
>
> > I get the same dump again.
> >
> > Am I doing something wrong?
> >
> > Guddler.