testing 6550s outside a 6502 bus

From: Francesco Messineo <francesco.messineo_at_gmail.com>
Date: Thu, 4 Jan 2018 18:56:53 +0100
Message-ID: <CAESs-_zc8RQUPN35wCgrFD+LX_pjXpA_XEsFg54QXo2CinJavw@mail.gmail.com>
Hi all,
as I'm repairing a 2001 320008 assy, I'm trying to test the 6550s and
6540s on a microcontroller board that I've made.
I would use a real 6502, but I've only one spare left, so that's not
an option :)

It seems that the 6550 latches the selects, address and R/W line (for
example lowering R/W after PHI2 L->H always results in a read cycle)
on the rising edge of PHI2, but still I can't make a correct read or
write cycle.
Did anyone succeed in reading/writing these outside a 6502 bus?
We can continue in private chat if anyone...
Best regards

Frank

       Message was sent through the cbm-hackers mailing list
Received on 2018-01-04 18:02:30

Archive generated by hypermail 2.2.0.