25 Apr
2005
25 Apr
'05
3:05 p.m.
Hi Marvin
They didn't have the intel part but did have a spec
sheet from Siemens on a SAB 8286/87. It seems that yes,
the i8287 is the part that will work on the board I've
been trying to get work. The current rate is a little
lower 32ma instead of 48ma but I doubt that will have
any effect on the SYM-1's bus.
The 8308 is configured differently on the enables.
It has separate receive and transmit enables. I needed
the T/R pin with the single Disable pin. This seems to match
the i8287 that I just located at Halted :)
The Am8303 you sent me matches the schematic I have for
the DP8303. The sheet for the SAB 8287 has the same
functions as the DP8303.
I think my search has endded. It would be great to have
a cross reference of these old chips.
Dwight
From: "Marvin Johnston" <marvin at
rain.org>
Just out of curiousity, wouldn't you really prefer the PDF datasheet for
the DP8303? It appears to be the same as an AM8308 (AMD) (Octal
Three-State Bidirectional Bus Transceivers) and I am guessing that the
suffix is "J". I couldn't find any info on the i8287 or uPD71087. At any
rate, check your email :).
In may searches for a DP8303, I have found
nothing.
I did find with the help of those in this group that
the 8304 was the same except non-inverted. Looking
for this part, I found that several places list
a 8286 as being the same. This is also refered to
as a uPD71086. While looking at the Jameco catalog,
I found the next list stated as an inverting buffer
with the number 8287. I believe this may be the same
as the 8303 that I've been looking for.
Can anyone tell me what the pinout is for either
a i8287 or a uPD71087 ??
Thanks
Dwight