Meet The Z80 Family of peripherals

names and part numbers

Originally there was no need to remember part number.
because the Z80 chips all had their name/function on them.

CPU	8400
DMA	8410
PIO	8420
CTC	8430
DART	8470
SIO	8440/41/42

Then NMOS gave way to CMOS
so the part number starts to matter:

NMOS CTC is Z8430
CMOS CTC is Z84C30

Then higher speed were available
and part numbers were inevitable.

MHZ	name	part number
2.5	Z80	z8400
4.0	Z80A	z84c0006
6.0	Z80B
8.0	Z80H
10		z84c0010
20		z84c0020

They click together almost like Legos

The beauty of the Z80's native peripherals
is the way they interface directly to the CPU.
No interrupt controller, no bus controller.

the tail that wagged the dog

Zilog SIO/ESCC	8250 / 1650

40 pin DIP	40 pin DIP
2 UARTS		1 UART
async/sync	async only
HDLC/SDLC	no

The z8440/1/2/4 SIO chip became more popular than the Z80 CPU:
ONE 40 pin DIP with dual independent serial channels
capable of async, sync, HDLC, SDLC protocols.
It is so smart it's almost a NIC in a chip.

HOW POPULAR WAS IT?

It was so popular
that the bus interface was made generic (for non-Z80 systems)
as the "SCC Serial Communications Controller"
part number Z80C30/Z85C30
(made by Zilog, second sourced by AMD, SGS, Mostek and others).
enabling Appletalk and SDLC mainframe connectivity.

part numbers:
Z08530 NMOS Serial Communication Controller
Z80C30 CMOS Serial Communication Controller

from datasheet for the
ESCC Enhanced Serial Communications Controllers Z80230/Z85230 Product Brief PB000402-0311

Zilog's Enhanced Serial Communications Controllers (ESCC, Z80230/Z85230)
are pin- and software-compatible members of the SCC family.
The ESCC is a dual-channel, full-duplex
multiprotocol data communication peripheral,
designed for use with both 8- and 16-bit microprocessors.
The ESCC is an enhanced version of Zilog’s industry
standard SCC core (Z08530) which was introduced by Zilog in 1981.