We have some devices from a vendor that are not tape drives, but which
respond to Sense Id and Read Device Characteristics as though they are
3480-04s. This works fine for the older model of the device; however,
the newer versions respond very badly to any legitimate tape command
that is not included in a list of 5 CCW Op codes that they need.
Unfortunately, Rewind and Unload is not a supported command. Because of
this, CP gets a CE/DE/UC with Command Reject whenever one of these
devices is detached from a user or a user logs off. This is not a good
thing because it boxes the device.

I can include RDEVICE statements in SYSTEM CONFIG to perhaps eliminate
the RUN problem. My question is, what can I specify that will work? I
can specify TYPE TAPE. Another possibility is TYPE UNSUPPORTED with
DEVCLASS TAPE. Will CP still issue the RUN command for these devices if
I include either of these potential circumventions? I would be surprised
if it did not. Is there a generic type and class I can use without fear
of introducing other problems? It probably would not be much of a change
to HCPDTD to bypass the RUN for an address range; however, something is
needed sooner rather than later.

I have expressed an opinion to the vendor that if a device is going to
tell the system that it is a 3480-04, then it ought not reject CCWs that
are legitimate for that type of device. It will probably be faster for
me to modify CP than for them to modify their devices.

Regards, 
Richard Schuh 


Reply via email to