[GreenKeys] USB-teletype adapters (update)

[Jones, Douglas W]

On Mar 28, 2016, at 11:13 AM, Gil Smith wrote:

> So, not including the start/stop bits:
> 
> 33 format is technically 7 bit plus parity or 7 bit plus mark for a total of 8 bits (7-P-2 or 7-M-2).

I believe Model 33 was also available with 7 plus space.  DEC ASCII paper tape tended to have bit 8 punched all the time, but I recall using TTYs that always had bit 8 unpunched, and others, of course, where bit 8 was parity.

Any USB to current loop device ought to support all 3 flavors.

I know that many glass TTYs had option switches for all 3 flavor (I have some ADM 31 and ADM 5 terminals gathering dust.  They support both current loop and RS232 interfaces).

		Doug Jones
		jones at cs.uiowa.edu