Microwriter MW4 help

[John S]

> From: john_a_s2004 at hotmail.com
> To: cctalk at classiccmp.org
> Subject: RE:Microwriter MW4 help
> Date: Tue, 12 Oct 2010 08:47:11 +0000
>
> Here's the adapter I used to read the 2564 in a 2764 programmer:
>
>
> 2564 pins       2764 pins
> 20 (A11)        23 (A11)
> 23 (A12)        2 (A12)
> 2+27(CS1+CS2)   22 (OE)
> 1 (Vpp)         28 (Vcc)
> 22 (PD/PGM)     20 (CE)
> (NC)            27 (PGM)
>
> All other pins connected straight through. The above can't be always used in the
> reverse direction (eg using a 2764 in a 2564 socket), as CS1 and CS2 may or may not
> be tied together depending on the circuit.
>

On the 2564 the chip is selected when CS1 and CS2 are both low, I thought perhaps a pair of diodes could be used to feed an OR of these signals to the OE (active low) on an 2764? If not then a 74LSxxx would have to pressed into use.

Regards,
John