hofbauer@utcsri.UUCP (John Hofbauer) (12/12/85)
This may not quite be the right group to post this query to, but it is the closest approximation I could find. How does an IBM 4341 or like machine running under CMS send a signal to an IBM 327x terminal to clear the screen. I hope it's some kind of escape sequence... if so, what is it? The local gurus are anything but and so haven't been able to help me.
callen@ada-uts.UUCP (12/18/85)
>***** ada-uts:net.arch / utcsri!hofbauer / 6:23 pm Dec 11, 1985 >This may not quite be the right group to post this query to, but it is >the closest approximation I could find. How does an IBM 4341 or like >machine running under CMS send a signal to an IBM 327x terminal to clear >the screen. I hope it's some kind of escape sequence...if so, what is it? >The local gurus are anything but and so haven't been able to help me. Hmmm...do you mean "how does the hardware work?" That's easy. There are *TWO* ways to clear the screen. One is by writing to the tube with an "erase-write" command, which clears the screen before writing your new data to it. The other is by including the following sort of "order sequence" in the data stream (note - I have macros to do this, but they are NOT supplied by IBM): SBA (1,1) Put cursor in upper left hand corner RA (24,80),X'00' Fill screen with nulls (assumes 24x80) SBA means "set buffer address", and moves a sort of invisible cursor around in the 3270 buffer. RA means "repeat to address", and it fills the buffer with the supplied character from the current buffer address to the supplied address. Here we fill it with null characters (which erases the screen). All this stuff is decribed in the following IBM manuals: GA23-0059 IBM 3270 Data Stream Programmer's Reference GA23-0061 IBM 3274 Control Unit Description and Programmer's Guide Unfortunately I don't know much (like zilch) about CMS so I don't know if there is an easy way to have CMS do this for you. Hope this helps. -- Jerry Callen Intermetrics, Inc. Cambridge, MA ...ihnp4!inmet!ada-uts!callen with BOILERPLATE; procedure Cover_My_Butt is use BOILERPLATE; begin Standard_Disclaimer; end;
brianu@ada-uts.UUCP (12/19/85)
Under CMS the program must execute a DIAGNOSE X'58' to clear the screen.
The instruction looks like this:
DIAG R3,R2,X'0058'
Where R3 is the address of a CCW and R2 is the console address.
Unlike Jerry Callen, I know CMS but not CCW's so here is the CCW's used
by a (not to be named) module: CCW DC X'1900000060FF0001'
DC X'0300000020000001'
I won't vouch for it validity, especially since I couldn't find the 19
command code listed anywhere.
Brian Utterback
Intermetrics Inc.
733 Concord Ave. Cambridge MA. 02138. (617) 661-1840
UUCP: {cca!ima,ihnp4}!inmet!ada-uts!brianu
LIFE: UCLA!PCS!TELOS!CRAY!I**2wizard@watdcsu.UUCP (Mailing List, Open Computing Group) (12/24/85)
In article <7900005@ada-uts.UUCP> brianu@ada-uts.UUCP writes: >The instruction looks like this: > DIAG R3,R2,X'0058' >Where R3 is the address of a CCW and R2 is the console address. >Unlike Jerry Callen, I know CMS but not CCW's so here is the CCW's used >by a (not to be named) module: CCW DC X'1900000060FF0001' > DC X'0300000020000001' >I won't vouch for it validity, especially since I couldn't find the 19 >command code listed anywhere. the CCW flags are where the erase write is specified. a DIAG 58 under CMS is equivalent (more or less) to an SIO in a real /370. the 3270 programmer's guide should have the specification of the CCW flags used. Herb Chong... User friendliness all over...