29 Aug
2005
29 Aug
'05
9:51 a.m.
Does anyone have the pinout for the Motorola MC6881 or MC3449 chip? (16
pin DIL package) (Those 2 devices are equivalents, the ones I have are
marked with both numbers.). From what I can tell, it's a triple
bidirectional bus switch.
They are used in the HP37201 HPIB extender, HP seem to have created
separate data buses for the memroy and I/O chips. I guess this device is
on-topic here, mine dates from 1979, a pair of them allow an HPIB bus to
be fed over various types of serial link, including asynchronous and
synchronous modems.
-tony
29 Aug
29 Aug
12:41 p.m.
... just put up the following:
http://www3.telus.net/~bhilpert/tmp/XC6881.gif
If you need more electrical specs let me know.
Tony Duell wrote:
Does anyone have the pinout for the Motorola MC6881 or MC3449 chip? (16
pin DIL package) (Those 2 devices are equivalents, the ones I have are
marked with both numbers.). From what I can tell, it's a triple
bidirectional bus switch.
They are used in the HP37201 HPIB extender, HP seem to have created
separate data buses for the memroy and I/O chips. I guess this device is
on-topic here, mine dates from 1979, a pair of them allow an HPIB bus to
be fed over various types of serial link, including asynchronous and
synchronous modems.
-tony
12:42 p.m.
... just put up the following:
http://www3.telus.net/~bhilpert/tmp/XC6881.gif
If you need more electrical specs let me know.
Thanks, I will take a look tomorrow when I am on a machine with some kind
of graphical display...
-tony
2:09 p.m.
On 8/29/05, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Does anyone have the pinout for the Motorola MC6881 or
MC3449 chip?
IIRC, Commodore used MC3449s in their IEEE-488 equipped CPUs and disks
(PETs, 2040s, 3040s, 4040s, etc.)
I don't know about just pinouts, but they should be locatable in
schematics on funet.
-ethan
3 p.m.
On 8/29/05, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Are you sure you're not thinking of the MC3446 or something like that?
Motorola made a number of GPIB buffers with numbers in that range (I've
come across serveral of them, I have data sheets on them).
The MC3449, as I now know, is basically a bidirectional multiplexer. I
The I/O levels are TTL, not strictly GPIB levels.
-tony
Does anyone have the pinout for the Motorola
MC6881 or MC3449 chip?
IIRC, Commodore used MC3449s in their IEEE-488 equipped CPUs and disks
(PETs, 2040s, 3040s, 4040s, etc.)
3:34 p.m.
On 8/29/05, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Are you sure you're not thinking of the MC3446 or
something like that?
Motorola made a number of GPIB buffers with numbers in that range (I've
come across serveral of them, I have data sheets on them).
Ah... I might be at that. Sorry for the confusion.
-ethan
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