Hi all,

1.
The most important invention of Intel on the 8051
was the EA pin.
So every 8051 can be used with external EPROM.
On the introduction of the 8051, most micros are only
factory programmable.
But only for high quantities (>10,000).
And so wrong programmed devices
can be still selled as cheap 8031 romless devices
(some of my 8031 can be read out).

So the 8051 was ideal for poor students to start with
micros and push it into its company later.
Iself starts also with nothing than a data book,
an 8031, a 74LS373 and a 27C64.

2.
Philips made later a wide range of 8051 derivates,
especially with the cheap and easy I2C bus

3.
Also later Atmel was the 1. company, which introduce
the first cheap flash 8051 derivates.
Only many many years later also other micro manufacturer
goes to flash.

4.
Since the architecture was good until today and further
improvements never stops (e.g. DS80C390),
its still a good choice.


Peter