Re: 6502 BE function ?

[Patrick Schaefer <pa.schaefer@fz-juelich.de>]

friedt@lpmo.univ-fcomte.fr wrote:
>
> As I do not have a datasheet of the original 6502, I am unable to figure out
> how to set its data bus, @ bus and R/W# to hiZ state. Is that done using the
> BE (bus enable) pin ? 

There is no bus enable. Usually pin 1 is connected to ground.

For a DMA circuit with bus hold get a copy of the Apple II Reference
Manual and look how the cpu section is designed. Basically you have to
set the RDY line low and disconnect the address bus using tristate
buffers.

There is a maximum time for the cpu to be stopped, after this time it
will need a reset to recover. 


Patrick