On Wed, 13 Jun 2001, Ian Castle wrote:
> ...Unfortunately it has a PLCC socketed BIOS - I wasn't expecting this
> from the photograph on the web site and some
> of the comments in previous weeks. But reading between the lines, Ron's
> hunting down of PLCC adaptors seems to
> imply that this is what he is using for the motherboard.
no, my 810lmr has a DIP. But I'm anticipating trouble such as this.
> I've also had no luck so far in getting hold of a DoC Millennium. The
> UK distributor (Arrow) mentioned on M-System's web site wants a
> minimum order value of �1000 ($1500 or so) - and this is a project
> funded with pocket money at the moment...
> - The BIOS chip is an SST inc. Multipurpose flash (MPF), 90ns,
> 256Kbits x 8. Which I guess means 256Kbytes which is too small for a
> Linux Kernel, but large enough for UTC Tiara. The part number is
> SST39VF020-90-4C-NH. (http://www.ssti.com/products/39lf_vfxxx.html).
> So I could look at using Tiara with this motherboard.
If you are stuck for size tiara is the way to go.
> - Is it possible to plug in a bigger part and have that work - I guess
> the 512K x 8 (39VF040) which seems to be available in the same
> packaging/voltage etc. This would be 512Kbytes which would do. Anybody
> know if this is possible?
no.
>
>http://rom-emulator.com/cgi-bin/index/index.cgi/PLCC/21156498/Adapters-with-ZIF-DIP-socket.htm
Anybody know? I need to know too.
> - The motherboard still has some bits of solder and silk screen stuff
> for where the DIP socket would have gone. Could I invest in a
> soldering iron and put a socket on the motherboard. Not a project for
> a beginner I suspect?
You should check the connectivity of the traces with a meter or at least
your eyeball ...
> - How does one go about flashing the existing chip?.... Boot up, build
> image (e.g. tiara) and hope that it still works - or are you using
Most people now burn chips by putting them in the mainboard and "doing the
deed". Much cheaper than a programmer.
But prying out a PLCC and putting in a different one with power on is a
big deal I think --- much messier than DIP!
We need some clever ideas from the list.
ron
