DCL(4)                OpenBSD Programmer's Manual (HP300)               DCL(4)

NAME
     dcl - HP 98628A communications link

SYNOPSIS
     device dcl0 at scode? flags 0x1

DESCRIPTION
     The 98628A is a buffered EIA RS-232C (CCITT V.28) communications inter-
     face.  It has one port with full modem control.

     Input and output for each line may set to one of following baud rates; 0,
     50, 75, 110, 134.5, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
     19200.

     An optional argument flags may be set to 1 if the line should be treated
     as hard-wired with carrier always present, or to 0 if modem control is
     desired.

     Use HP cable "98626 & 98628 opts.002, RS232-C DCE CABLE, 5061-4216" to
     attach non-modem devices.  Use HP cable "98626 & 98628 opts.001, RS232-C
     DTE CABLE, 5061-4215" to attach modems.

     The 98628A has a 256 byte input silo and a 256 output silo. Input inter-
     rupts happen on a per character basis.

     The high water and low water marks in the kernel tty routines are com-
     pletely inappropriate for a device like this with a large input buffer.
     Don't use tandem mode if possible.  A fast system can handle input at
     19.2K baud without receive overflow.

     For output to devices that make heavy use of XON/XOFF a write size of
     less than 256 will improve performance marginally.

FILES
     /dev/ttyl[0-9]

DIAGNOSTICS
     dcl%d: error 0x%x RESET CARD.  Where the errors are encoded:

           0x06 card failure
           0x0d uart receive overflow
           0x0e receive overflow
           0x0f missing external clock
           0x10 cts false too long
           0x11 lost carrier
           0x12 activity timeout
           0x13 connection not established
           0x19 illegal databits/parity
           0x1a register address out of range
           0x1b register value out of range
           0x-- unknown error

SEE ALSO
     tty(4)

HISTORY
     The dcl driver currently under development.

BUGS
     Breaks received at a faster rate then 1 break every second will be recog-
     nized as a single break.

     Console use is not supported.
     The RS-422/423/499, MTS-DSN/DL modes of the card are not supported.

OpenBSD 2.8                     March 27, 1991                               1
