UARTs (was: Switch settings: Facit 4070 tape punch) - test-drb@ccmp.vtda.org

17 Mar 2008

Date: Sat, 15 Mar 2008 13:06:36 -0700
From: dwight elvey <dkelvey at hotmail.com>
Subject: RE: UARTs (was: Switch settings: Facit 4070 tape punch)

...
 > According to the Marketing Memo from GI announcing
the discontinuation
> of the AY-5-1013, the -A replacement is identical except for the higher max
> baud rate (in fact, it is a 5-1013 that has been tested to 40kb instead of 30).

...
 Hi
 For AY-5-1013 to AY-5-1013A, I reference the table on page ten of the document.
 I don't disagree with the maximum rates but the table does show different stop bits.
 For most users, of old systems, 1200 or 9600 was maximum so the top rate of 
 the part is of no special value.
 Dwight 
Not to belabour the issue, but since cross-references are notorious for their
inaccuracies I think I'll go by GI's AY-5-1013/A datasheet, especially since
they made a point of issuing a bulletin to their customers assuring them that
the 5-1013A was in fact a 5-1013 selected for the higher baud rate. Also 
notice that this part was marked on your cross-reference with a note
to consult the factory for detailed interchangeability information.

Other cross-references list these SMC equivalents:
AY-5-1013	COM2502
AY-5-1013A	COM2502H (not 2017)
And it makes more sense that the same number with a different suffix would
indeed be the identical part with a different speed.
(e.g. http://tvservice.org/components/CROSSREF.PDF)

Finally, GI part numbers are easily confused. As an example, if you want
to look at the AY-5-1013A data sheet to convince yourself that it is indeed
a 1 & 2 stop bit UART, you will find it at datasheetarchive.com and
alldatasheet.com, but listed as an AY-3-1013 at the former, and AY-3-1013A
at the latter (neither of which, AFAIK, was ever a valid GI part number).

I just wanted to set the record straight in case someone for whom it's actually
relevant reads this thread some day.

m