neese@adaptx1.UUCP (05/16/91)
>/* ---------- "Maxtor 8760S SYNCHRONOUS w/Adaptec" ---------- */ >I have a Maxtor 8760S (among other things) attached to an Adaptec 1542b. >The manual the Maxtor people sent me for the 8760 drive states that the >drive is capable of doing SYNCHRONOUS transfers. It seems that there is >no jumper on the drive for setting it that way, but instead the drive >depends on receiving an instruction (from the host adapter?) to set it >to synchronous mode. > >I have set the synchronous mode jumper on the 1542b. SCSICNTL reports >the adaptec as being set that way. However, when I query the Maxtor drive, >it says "NO" next to the synchronous menu item. Note that the several >other devices on the bus don't (to the best of my knowledge) (they are >cdc wren IV, Archive Viper 2150S, Toshiba MK156FB) support sync transfers. > >Is there a way to get the maxtor into sync mode? Wouldn't this drastically >improve overall performance, at least while accessing that drive? Bill, if you are talking about the window that displays the INQUIRY data and shows all the options available, this doesn't mean the drive will not support the sync message. In some interpretations of this data, the vendor may think that this bit means the peripheral has the ability to negotiate for sync. In this case, the Maxtor is correct. If the window showing the 1542 settings show the device as running sync, it is running sync. No guess work here. If you want to absolutely check, you need to snoop on the SCSI bus. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese
bill@unixland.uucp (Bill Heiser) (05/19/91)
In article <283400114@adaptx1> neese@adaptx1.UUCP writes: > >Bill, if you are talking about the window that displays the INQUIRY data >and shows all the options available, this doesn't mean the drive will not >support the sync message. In some interpretations of this data, the vendor >may think that this bit means the peripheral has the ability to negotiate >for sync. In this case, the Maxtor is correct. >If the window showing the 1542 settings show the device as running sync, it is >running sync. No guess work here. If you want to absolutely check, you need >to snoop on the SCSI bus. Yes, that's the window. It's something like "show drive configuration" or something like that. It shows "NO" for all of the possible parameters (except ANSI compliance). I would have expected that it says "yes" for "SYNC TRANSFERS" ... So I guess that this point I don't know how to determine whether the maxtor and adaptec card have negotiated sync communications. Is this something that gets "set" and always works that way from then on, or does the negotiation occur on every transfer? Thanks for your response. Bill -- bill@unixland.uucp The Think_Tank BBS & Public Access Unix ...!uunet!think!unixland!bill ..!{uunet,bloom-beacon,esegue}!world!unixland!bill 508-655-3848 (2400) 508-651-8723 (9600-HST) 508-651-8733 (9600-PEP-V32)
neese@adaptx1.UUCP (05/22/91)
>>Bill, if you are talking about the window that displays the INQUIRY data >>and shows all the options available, this doesn't mean the drive will not >>support the sync message. In some interpretations of this data, the vendor >>may think that this bit means the peripheral has the ability to negotiate >>for sync. In this case, the Maxtor is correct. >>If the window showing the 1542 settings show the device as running sync, it is >>running sync. No guess work here. If you want to absolutely check, you need >>to snoop on the SCSI bus. > >Yes, that's the window. It's something like "show drive configuration" >or something like that. It shows "NO" for all of the possible parameters >(except ANSI compliance). I would have expected that it says "yes" for >"SYNC TRANSFERS" ... So I guess that this point I don't know how to >determine whether the maxtor and adaptec card have negotiated sync >communications. Is this something that gets "set" and always works >that way from then on, or does the negotiation occur on every transfer? It is a set it once and forget it type of transaction. The only other time the 1542 will re-negotiate for sync transfers happens after a SCSI bus reset. The host adapter window information will show what the adapter negotiated for. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese