Hello everyone,

There's something that makes me wonder.

In the 1970s, Intel's i8080 and Zilogs Z80 were competitors.

The Z80 was made by ex-Intel employees who foundet Zilog and which did work on the i8080s previously.

The Z80 had a numerous features over the i8080, but was cheaper in price and binary compatible.
Some of these features were a single 5v voltage (ttl comppatible) and an internal DRAM refresher.
Which both were a big success.

Intel subsequently released the i8085, with a few extra instructions and also a 5v supply voltage,
but no internal DRAM refresher.
While thst chip was used in a few applications, it never came close to the famous Z80.

Now, why didn't Intel learn from this, I wonder?
Why didn't have the i8080's bigger brother, the i8086, featured a DRAM refresher?
Or its "castrated", low-cost version, the i8088, at least? Wasn't it meant to suit cheap 8-Bit motherboard designs, after all?

I know there was the late 80186/80188 from 1982 later on (-with DRAM refresher, but other incompatibilities-), but it was just like another i8085.

Why were no lessons learned?
Does anybody have any clues or theories about this matter?

Best regards,
Jo22