20 Dec
2009
20 Dec
'09
4:13 a.m.
jd wrote:
Perhaps the 8291 used less code on the
microcontrollers? Or perhaps it
could do seomthing on it's own, unlike the 9914, such as assert NRDF
when it's databuffer was full? Come to think of it, wasn't the 8291
almost "smart", like a hard coded microcontroller?
The 8291 appears to have been hardwired logic; the microcontrollers of
the time would not have been able to transfer data at anywhere near the
speed of the 8291. The 8292, which was used to implement bus controller
functionality, appears to have been an 8041 "UPI". That's a
mask-programed 8048 derivative which has a slave interface to a
processor bus, to act as a smart peripheral.
Eric