National Semiconductor Mass Storage Handbook

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Hi Tony,

Thanks Al for the heads-up on the datasheets !! Tony, do you think it is
some kind of  Manchester / Miller encoder / decoder ? Do we know if it is a
National chip or has it's total identity been wiped ? Maybe Signetics or
Plessey or TI or ?? Where are the power pins ( sometimes that is a good
tell ) ?   You mentioned 24 pin skinny DIP ? I'll keep looking. This is for
some type of magnetic disk / floppy media system ?

Pinouts are the same for the AMD 8051 / 8053. Hope that helps.

Best regards, Steven

> >
> > Tony,
> >
> > I have a datasheet for the DP8464 ( supposed to be similar to the 8468 )
and
>
> That datasheet is on Datasheetarchive, so I'd got a pinout of that. The
> 8468 is similar in consept, but has more pins (I think it only came in a
> PLCC package) and thus a diferent pinout
>
> > a bunch of Application Notes for using that family of parts ( i.e.
AN774,
> > AN414, etc..). It would be helpful to know if it is a pulse detector,
data
> > separator or whatever function you think it might serve.
>
> Thanks to Al Kossow, I've now seen all the datasheets (on bitsavers) and
> know that, alas, none of them apply to the chip I am looking at. The
> power and groudn pins don't agree, for example.
>
> All I can tell you is that it's some kind of data encoder/decoder. The
> Read and Write data signals, together with the Read and Write clock lines
> go directly to it. I've not traced out enough to know more.
>
> >
> > I also have a datasheet for the AMD8751 / 8753 which are the EPROM
versions
> > of the factory mask ROM  8051 and 8053. The 8753 has 8 K of EPROM and
same
> > functionality as the 8051 / 8751 ( 4 K ROM / EPROM ).
>
> If you've got the data sheets to hamd, can you check if it's the same
> pinout as the 8051, please (it looks to be).
>
> -tony