wales@CS.UCLA.EDU (02/17/88)
I have long noted that a couple of programs I run have a tendency to
mess up my speaker, so that one or more "beeps" from the speaker end
up being toneless "clicks" instead.
My machine is a Wugo PC-II-AD (a Taiwanese "turbo" XT clone with an
8-MHz NEC V-20 processor), marketed by Sun Computers Inc. (not to be
confused with Sun Microsystems Inc.). As far as I can tell, it is com-
pletely IBM-compatible; I have yet to encounter any "IBM or 100% compat-
ible" software that fails to run on it.
Two programs I am aware of which tend to cause this "click" mode are
the Leading Edge Word Processing program and the Spinnaker Backgammon
game. Among the programs which thereafter suffer from "click" syndrome
are ProComm 2.4.2, and a disk parking utility (PARK, version 2.00, by
Corona Data Systems). Spinnaker Backgammon suffers from the "click"
problem as well as causing it -- about half of its "beeps" come out as
"clicks", with no pattern that I have been able to discern. I am sure
there are other programs which cause and/or suffer from this problem,
but these are the ones I am personally familiar with.
If I run the DOS command "ECHO ^G" (control-G), it always "beeps", and
a subsequent command does not suffer from "click" syndrome. (I am using
the NANSI terminal driver.) So, whatever the NANSI driver does for a
"bell", it clears up the problem with apparent 100% reliability.
After running one of the "click-causing" programs, I used DEBUG to look
at the status of the 8253 programmable timer chip. The count register
of timer #2 (I/O port 42H) consistently shows a value of 2 (i.e., the
first "i42" DEBUG command gives "02", while a second "i42" gives "00").
If I subsequently reset the counter manually (e.g., to 400H, via the
DEBUG sequence "o43 6B", "o42 00", "o42 04"), and then activate the
speaker by setting the two low-order bits of I/O port 61H, frequently
all I get is a "click" -- no tone. If I repeat the "counter set"
sequence, however, I get a tone as expected.
The above manual procedure is *not* 100% reliably repeatable. However,
it does work often enough that there seems to be little doubt in my mind
but that I am seeing some kind of problem relating either to my 8253
timer chip or to the support circuits.
I haven't been able to get my hands on a "true blue" IBM PC or PC/XT to
see if the problem occurs there. I did try running Spinnaker Backgammon
on an IBM PC/AT and PC/XT Model 286, without observing the "click" prob-
lem; however, these are 286-based systems and undoubtedly differ in the
clock timer components and circuitry they use, so my failure to get them
to "click" is probably meaningless.
My questions for the net:
(1) Has anyone ever observed this problem on a "true blue" IBM PC or
PC/XT? Is this a generally recognized problem and not simply a flaw
in a handful of Taiwanese turbos?
I assume, by the way, that it *is* a generic problem -- since, for
instance, I remember several people talking about it on Datastorm's
BBS (Datastorm being the ProComm company). For what it's worth, the
Datastorm people were apparently unaware of the problem and had not
a clue as to what might be causing it. This may mean it doesn't
happen on "true blues" -- or it might simply mean that the Datastorm
people aren't using any of the "click-causing" programs.
(2) Does anyone know what is causing the problem? Is there, by any
chance, a standard hardware fix for it on the IBM PC and PC/XT?
(3) What programming techniques are commonly accepted as workarounds for
the problem?
-- Rich Wales // UCLA Computer Science Department // +1 (213) 825-5683
3531 Boelter Hall // Los Angeles, California 90024-1596 // USA
wales@CS.UCLA.EDU ...!(ucbvax,rutgers)!ucla-cs!wales
"Sir, there is a multilegged creature crawling on your shoulder."mrh@camcon.uucp (Mark Hughes) (02/29/88)
From article <9506@shemp.CS.UCLA.EDU>, by wales@CS.UCLA.EDU: > I have long noted that a couple of programs I run have a tendency to > mess up my speaker, so that one or more "beeps" from the speaker end > up being toneless "clicks" instead. > > My machine is a Wugo PC-II-AD (a Taiwanese "turbo" XT clone with an > 8-MHz NEC V-20 processor), My Amstrad PC1512 shows identical symptoms, although I don't know which programs may be responsible. (Although I am generally running Procomm v2.3 when it occurs). -- ------------------- UUCP: mrh@camcon.uucp / ..uunet!mcvax!ukc!camcon!mrh | Mark Hughes | Telex: 265871 ref:MAG70076 |(Compware . CCL) | BT Gold: 72:MAG70076 ------------------- Teleph: Cambridge (UK) (0)223-358855
vg55611@ihuxy.ATT.COM (Gopal) (03/06/88)
I have a small program (TSR) that can be used to set the length of the beep - it works by trapping INT 10 calls to output char \007 TTY style. This may work as a solution for you. Anyone interested can email me. Venu P. Gopal ihnp4!ihuxy!vg55611
ajmyrvold@violet.waterloo.edu (Alan Myrvold) (03/15/88)
To add to the unravelling of the problem of the mysterious clicks, I did not used to get them, but now I do. I get them only after running KERMIT 2.30 I did not get them with KERMIT 2.29 PROCOMM seems to display the problem when it occurs. ------------------------------------------------------------------- What? You were in the next room all this time? I would have just come over to see you! ------------------------------------------------------------------- Alan Myrvold ajmyrvold@violet.waterloo.edu -------------------------------------------------------------------