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

15 Mar 2008

...
 >> Difference between A and non-A is number of
stop bits.  
...
   In what way?
The UARTs I am familiar with have a single pin that selects 
 between either 1 or 2 stop bits (1 or 1.5 stop its if the word length is > 5 
 bits). What does the other type do? 
  -tony I my meant that the primary difference was that one could do 1.5 
 stop bits while the other could do 2. There is also the differences in supply 
 voltages as mentioned by others. Still, as far as how they work, the data 
 sheet in the catalog I point to is more than I've seen in other places. 
 My IMSAI has the AMI chip. I recall programming it with just the pinouts. 
 Dwight  ---------
I'm afraid I have to disagree with you again, Dwight:

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).

The AY-3-1014A (there was no 1014) and 1015 are the two UARTS that use
1 1/2 stop bits instead of 2 in 5 bit mode.

Looks like this previous post of mine didn't make it, so I'll repost it here:

AY-3-1014A*	CMOS, 480kHz/30kb
AY-3-1015*	NMOS, 480kHz/30kb
AY-5-1013	PMOS, 480kHz/30kb	
AY-5-1013A	PMOS, 640kHz/40kb
AY-6-1013	PMOS, 360kHz/22.5kb

* = 1 1/2 Stop bits
PMOS = +5 & +12V, NMOS = +5V only

m