vic@cuff.uucp (Victor Berry) (03/19/91)
We have a HP 9000 model 345, that we use for access, via UUCP, to the world. There is no expansion chassis and we are confined to the 98626 serial interface. The problem is that in the termio definition in section 7 of the manual the following quote appears. "Data Loss can occur with the HP 98626/98644 serial interfaces if the effective combined data rate for all installed serial interfaces exceeds 2400 baud (for example, two interfaces running at 1200 baud and a third at 300 baud is equivalent to 2700 baud combined)" You read that right... SLOW. This interface has no problem in the outward direction. We could talk out at 9600 all day long. The difficulty lies in incoming data. It will and does lose data at speeds above 2400. We actually run it at 4800 but it times out frequently. My question is: -------------- Does anyone out there in netland know of a way to speed this port up? Hopefully there is a patch or something. We have noted that the port ceases to function when the disk spins. So I would also be interested in any info I could get on RAM Disks for the HP. We really like the News and UUCP access we get from it but 2400 baud from a multi-thousand dollar machine seems a bit ridiculous. -- -- Is that real poncho, or is that a _Sears_ poncho?
jeff@dsndata.uucp (Jeff Minnig) (03/19/91)
In article <1991Mar18.162849.27463@cuff.uucp> vic@cuff.uucp (Victor Berry) writes: > > This interface has no problem in the outward direction. We could talk out > at 9600 all day long. The difficulty lies in incoming data. It will and > does lose data at speeds above 2400. We actually run it at 4800 but it > times out frequently. > > My question is: > -------------- > > Does anyone out there in netland know of a way to speed this port up? > Sorry, there is no patch for the 98626. I believe you problem lies in the fact that the 98626 has only a 1 byte I/O buffer on the card. When the data rate gets too high, kernel<->card link simply loses chars and becomes unusable. We have seen this type of behavior both from the 98626 and the 98644 cards, both of which only have a 1 byte buffer. My recommendation is to replace the 98626 card with a 98642A MUX card. The 98642A MUX card has a 128 byte input buffer and a 16 byte output buffer on the card. We have run everything from a Hayes 1200 to a Telebit T2500 @ 19200 baud on a 98642A card with no data problems. The 98642A card specs like this: Electrical Interface: IEA $S232C, CCITT V.28 Number of ports: 4 (1 modem, 3 direct-connect) Data rates: 110 to 19200 I/O Buffer Size: 128/16 bytes per port Character Size: 7 or 8 bits Parity: Odd, Even, or None Stop Bits: 1 or 2 (6..8 bits/char) Hardware Handshake: Provided by HP-UX per tty(4) Software Handshake: Provided by HP-UX per tty(4) Interrupt level: 3..6 (default of 3) Aggregte MUX thourghtput is card-limited to 76800 bps continuous input data. -jeff- -- ---------------------------------------------------------------------- I said it, not the people I work for. ---------------------------------------------------------------------- Jeff Minnig | (402) 476-8278 Design Data | 1033 'O' St. Suite 324 | {hpfcla,sparky,unocss}!dsndata!jeff Lincoln NE 68508 | ---------------------------------------------------------------------- Home is where your keyboard is. ----------------------------------------------------------------------
rjn@hpfcso.FC.HP.COM (Bob Niland) (03/20/91)
re: > We have a HP 9000 model 345... > ...that we use for access, via UUCP, to the world. There is no expansion > chassis and we are confined to the 98626 serial interface. The problem is > that in the termio definition in section 7 of the manual the following > quote appears. > "Data Loss can occur with the HP 98626/98644 serial interfaces if the > effective combined data rate for all installed serial interfaces exceeds > 2400 baud (for example, two interfaces running at 1200 baud and a third at > 300 baud is equivalent to 2700 baud combined)" Are you using an actual 98626A plug-in card, or the built-in serial interface of the 345? If you are using the built-in "98626", it has some advanced features that were turned on at release 7.05, and for which a 7.0/7.03 patch is available. These features include a 16-byte FIFO and CTS/RTS bi-directional hardware flow control. With both enabled, you should be able to operate reliably at speeds above 2400 bps. Contact your HP support representative for a copy of the patch. If they don't have it, they can obtain it from me via email (it is not on our normal patch system). Regards, Hewlett-Packard Bob Niland Internet: rjn@FC.HP.COM 3404 East Harmony Road UUCP: [hplabs|hpfcse]!hpfcrjn!rjn Ft Collins CO 80525-9599
gregb@hpindda.cup.hp.com (Greg Buchanan) (03/21/91)
In response to the question about the 98644 card on an HP9000/S345. Sorry, but 2400 baud is as fast as it can go on inbound without losing data. That is why the documentation tells you this. The problem is due to the UART used on the card only having a single byte buffer for inbound data. When the system gets busy processing the disk or other I/O, it cannot answer the Serial Card interrupt before the single byte gets overwritten. Greg Buchanan, HP Grenoble Network Divisions, Cupertino