26 May
2006
26 May
'06
9:42 a.m.
I have data sheets on the generic 82C55, what I'm looking for is
specifically the speed rating for the Mitsubishi 82C55AP-2... the
reason it matters is that the SBC6120 needs a 5MHz part, and many
82C55s are 2MHz.
Thanks for any pointers.
-ethan
26 May
26 May
10:18 a.m.
Ethan Dicks schrieb:
I have data sheets on the generic 82C55, what I'm
looking for is
specifically the speed rating for the Mitsubishi 82C55AP-2... the
reason it matters is that the SBC6120 needs a 5MHz part, and many
82C55s are 2MHz.
I haven't found an explicit datasheet for Mitsubishi, but:
typically, the -2 means 2MHz for other manufacturers, and since there
appears
to be a 82c55AP-3 and AP-5 available as out-of-stock part, I suspect
that the
-2 also means 2MHz for Mitsubishi. So you likely got a 2MHz part.
Fortunately,
82c55-5 chips are not so rare (see unicornelectronics, for instance).
--
Holger Veit
10:27 a.m.
On 5/26/06, Holger Veit <holger.veit at ais.fraunhofer.de> wrote:
Ethan Dicks schrieb:
> I have data sheets on the generic 82C55, what I'm looking for is
> specifically the speed rating for the Mitsubishi 82C55AP-2... the
> reason it matters is that the SBC6120 needs a 5MHz part, and many
> 82C55s are 2MHz.
I haven't found an explicit datasheet for
Mitsubishi, but:
typically, the -2 means 2MHz for other manufacturers, and since there
appears to be a 82c55AP-3 and AP-5 available as out-of-stock part, I suspect
that the -2 also means 2MHz for Mitsubishi.
Very likely, but I have a dim memory of a vendor (don't recall which
one) that doesn't
append the speed rating explicitly, it's a -1 -2 -3 thing where you
have to have the datasheet to cross-reference the particular speed in
MHz. I was hoping that Mitsubishi might be the one.
-ethan
3:06 p.m.
On 5/26/2006 at 12:18 PM Holger Veit wrote:
typically, the -2 means 2MHz for other manufacturers,
and since there
appears to be a 82c55AP-3 and AP-5 available as out-of-stock part, I
suspect
that the -2 also means 2MHz for Mitsubishi. So you
likely got a 2MHz part.
Fortunately, 82c55-5 chips are not so rare (see
unicornelectronics, for
instance).
Since I was in the same position a couple of months ago, there is a glaring
exception to this: NEC.
The uPD 8255AC-2 is rated at 5 MHz and the 8255AC-5 is rated at (ready for
this?) 4 Mhz!
Cheers,
Chuck
27 May
27 May
1:53 a.m.
On 5/27/06, Chuck Guzis <cclist at sydex.com> wrote:
On 5/26/2006 at 12:18 PM Holger Veit wrote:
Thanks, Chuck. That was almost certainly the particular vendor I was
dimly remembering.
So it seems that the Mitsubishi "-2" parts are most likely 2MHz, but
I'll keep an eye out for NEC "-2" parts.
-ethan
typically, the -2 means 2MHz for other
manufacturers...
I suspect that the -2 also means 2MHz for Mitsubishi. So you
likely got a 2MHz part.
Since I was in the same position a couple of months ago, there is a glaring
exception to this: NEC.
The uPD 8255AC-2 is rated at 5 MHz and the 8255AC-5 is rated at (ready for
this?) 4 Mhz!
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days inactive
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