From: zzyyzz@mixcom.com (Vincent Mulhollon) Subject: Re: Z80 Reset question Date: 1 Jun 1996 01:38:36 GMT Rocky (suesound@iafrica.com) wrote: : Maybe you could use the /BUSRQ signal - that definitely causes the bus : to be released. I think /RESET does not tri-state the /WR & /RD lines but : /BUSRQ does. "The Z80 microcomputer handbook" William Barden, Jr, 1978, page 29 says: "When /RESET is brought low, the following actions occur: 5. The address bus goes to a high-impedance state. 6. The data bus goes to a high-impedance state. 7. All output-control signals go to the inactive state." So "Rocky" is right. /WR and /RD go high, NOT high-z. Might I suggest OR logic for the /WR and /RD with a few invertors and stuff? Of course, /BUSRQ will actually do what you want. Extra credit for you if you implement handshaking with the /BUSAK signal. Vince Mulhollon N9NFB