What the Z80's pins do...

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Note:
There is extensive use of “Tooltips” text to support learning which do not seem to render on a Smartphone. Therefore this site is best viewed via a computer’s HD monitor

The 16-bit address bus pins are all outputs

The 8-bit data bus is bi-directional (determined by the state of /RD or /WR)

/M1 and /RFSH are rarely used

/BUSRQ and /BUSACK are rarely used (because DMA is rarely used on the Z80)

I have NEVER seen /HALT being used !! It goes low when the Z80 HALT instruction is executed

/WAIT is an active-low input used to force the Z80 to slow down

Image#1: Taken from the Zilog Z80 CPU User Manual Fig 3, Page 19

Important Note:
You can find images, etc, of Z80 Pinouts on the Internet… I looked at loads
ALL the ones I looked at were INCORRECT !!
NOBODY who actually has any real knowlege of Z80 hardware WOULD EVER publish incorrect information !! ¹ Discussion here