danielw@wyn386.mi.org (Daniel Wynalda) (04/19/91)
I have a bunch of 60 MB tape drives in house. They vary from Archive to Wangtek to Caliper. All of the drives are similar in design and take the same type of tape cartridge. I have a machine here that doesn't seem to like my tape drives and I can't find anywhere that explains the error messages I receive from the drivers. All of the drives appear to have this characteristic on this machine: If I TURN OFF the computer, and re-boot SCO Xenix 386 2.2.3 (the machine is a 33Mhz 80386/33 from DTK), the tape drive will work fine -- for a while. I've noticed I can cause the error in 33Mhz mode, but if I turn off the cache (turbo mode), things appear to work normally again (after a reset of the tape drive). I get one of the following from the kernel on the console when the drive freezes up. -- Wed Apr 17 13:42:58 ct cmd error(2,40) Wed Apr 17 13:43:38 ct cmd error(2,C0) Wed Apr 17 13:52:32 ct cmd error(1,60) -- I've looked everywhere in the manual and can't find any reference to these error messages. I'm sure they mean something to someone at SCO but not to me.... Could someone explain where these come for and what it is I have a problem with? I see the (1,60) error more than the rest and I imagine its a speed related problem, but I'm not sure... I get a similar problem with the Caliper drive on an 80386/25 occasionally -- that machine is running Xenix 386 2.3.2. Any hints? -- Daniel Wynalda | (616) 866-1561 X22 Ham:N8KUD Net:danielw@wyn386.mi.org Wynalda Litho Inc. | 8221 Graphic Industrial Pk. | Rockford, MI 49341
paulz@sco.COM (W. Paul Zola) (05/04/91)
In article <892@wyn386.mi.org> danielw@wyn386.mi.org (Daniel Wynalda) writes: }I have a bunch of 60 MB tape drives in house. They vary from Archive }to Wangtek to Caliper. All of the drives are similar in design and take }the same type of tape cartridge. I have a machine here that doesn't }seem to like my tape drives and I can't find anywhere that explains the }error messages I receive from the drivers. } [ questions about the meaning of ct cmd errors deleted ] The following article from the SCO Information Tools database should help with your problem. I'm posting because I think this may be of general interest. ################## cut here ################ cut here ################## Generic QIC-02 tape drive: "ct cmd error(%d, %b)". RELEASE: SCO XENIX System V Operating System Generic SCO UNIX System V/386 Operating System Generic PROBLEM: The message "ct cmd error (%d,%b)", where %d is 0, 1 or 2 and %b is a a hexadecimal number, appears quite frequently when the tape drive is in use. CAUSE: The interrupt handler contains a loop which polls the tape, waiting for the status to say Ready or Exception. If neither bit gets set in a reasonable amount of time, the loop runs out and the status read may not be accurate. As machines have become faster, this time period may have become too short for some configurations, and hence the error messages. SOLUTION: The error codes %d and %b in the message "ct cmd error (%d, %b)" indicate the following, depending on the values of %d and %b: when %d is: it means the tape driver is: --------------------------------------------------------- 0 trying to sleep at interrupt time 1 waiting for READY or EXEC has failed 2 waiting for READY, active has failed when %b is: the command issued to controller is: ---------------------------------------------------------- 0x20 position tape 0x40 write data 0x60 write file mark 0x80 read data 0xa0 read file mark 0xc0 read status 0xff impossible command value ################## cut here ################ cut here ################## I hope this helps you with your problem. - Paul Zola Support Technical Lead, Operating System paulz@sco.COM Gotta tend the earth if you want a rose. - Emily Saliers DISCLAIMER: I speak for myself, and not for SCO. } }-- }Daniel Wynalda | (616) 866-1561 X22 Ham:N8KUD Net:danielw@wyn386.mi.org }Wynalda Litho Inc. | 8221 Graphic Industrial Pk. | Rockford, MI 49341
mcs@fps.com (Mike Sanfratello) (05/10/91)
In article <16615@scorn.sco.COM> paulz@sco.COM (W. Paul Zola) writes: > >PROBLEM: The message "ct cmd error (%d,%b)", where %d is 0, 1 or 2 > and %b is a a hexadecimal number, appears quite frequently > when the tape drive is in use. > >CAUSE: The interrupt handler contains a loop which polls the tape, > waiting for the status to say Ready or Exception. If neither > bit gets set in a reasonable amount of time, the loop runs out > and the status read may not be accurate. As machines have become > faster, this time period may have become too short for some > configurations, and hence the error messages. This is very poor driver construction; blind spin loops should be outlawed! I've seen the ct driver source, and I'm sure you'll agree with me that this is a very poor example of a tape driver and should be redone.