Pinout for SED9421

[Allison]

>
>Subject: Pinout for SED9421
>   From: lee davison <leeedavison at yahoo.co.uk>
>   Date: Sat, 26 Nov 2005 01:13:45 +0000 (GMT)
>     To: cctalk <cctalk at classiccmp.org>
>
>>> 6850 Async UART clocked at 125K bits/s, and a PIO for the control
>>> lines.
>
>>> Lee.
>
>> Sure it wasnt the 6852 SSDA? UARTs generate start and stop bits and
>
>I checked the OSI610 schematic before replying. 8^)=
>
>Lee.

Figures..  However they loose a full sector for every four which is
pretty bad considering sync and other overhead that floppies incur.

I'd used the 6850 in my first tape system back in '75-76 as it was 
available and worked well without baud rate clock scaling to do block 
replaceable FM format at around 30 kbaud.  Problem was the tapes I used
only got 60k of usable storage due to overhead.  Going to a sync part
upped that to 80k.  Then I found a decent floppy that was affordable.


Allison