12 Oct
2010
12 Oct
'10
3:03 p.m.
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