>From: "Philip Pemberton" <philpem_at_dsl.pipex.com>
>
>Stan Barr wrote:
>> While looking for some op-amp chips earlier I came across a
>> couple of 8751s (labelled Intel '80). A quick google search
>> failed to turn up a data sheet, anyone any ideas where I can
>> look?
>IIRC, the 8751 is an EPROM (windowed package) version of the 8051 MCU. The
>thing about the 8051 (and the 8052) is that it can also be used as a CPU -
>add a 74LS573 (or 74LS373) latch and a bit of decoding and you can disable
>the internal program memory and use external memory instead.
This is the EA pin. It controls where the program memory is.
The 8031 ( 8032 ) is the version that is sold to be used this
way. As far as I know, the 8031's are just units that the
mask part failed or overruns of mask 8051 parts. Early
on, 8031's, with EPROMs were more common in keyboards and newer
keyboards use just 8051's.
Dwight
I use
>8051-derivatives a fair bit - Atmel's AT89S8252 is a particularly nice
>chip - basically an 8052 with 8k of internal FLASH memory and an SPI
>programming interface.
>
>Later.
>--
>Phil.
>philpem_at_dsl.pipex.com
>http://www.philpem.dsl.pipex.com/
>
>
Received on Mon Jan 20 2003 - 17:48:01 GMT