[net.micro.cbm] 1670 modem repair

dennisf@marque.UUCP (flaherty) (04/19/86)

	If anyone has ever considered buying a modem for Commodore's micros,
I can highly recommend the new 1670.  The software that comes with it (such
as emulators, terminal programs, etc.) are invaluable and the near
Hayes-compatibility make the 1200 bps modem a required peripheral (I live in
a freshmen dorm, so my modem watches my phone line at night for prank calls).
	My modem, however, has a problem.  You see, it's quite incon-
siderate.  It works just fine if my disk drive is turned on while I
use my modem.  That's its trick.  When I think it's going fine and turn
the disk drive off for the night, the modem becomes nasty if I want to
dial out ("ATD...").  After the modem dials the number, it waits no more
than a half second when SUDDENLY it spits out a bunch of loud glitches,
mostly x's, which knock me off the line!!  How obnoxious!
	I've tried ATZ and ATS7=10 to stop the cruelty, but they do 
nothing.  I wrote to Commodore Customer "Support" and all I got
was an ad and a free sample of Commodore Microcomputer Magazine
(Perhaps I should complain monthly?).  The only way I've found that
works is to turn the 1541 back on, but I don't want to do that.
	Does anyone have any suggestions?  Does Commodore service the
equipment?  Is there something inside that I can fix?  Repair?  Advice
or instructions would be greatly appreciated.
   
                                                Dennis Flaherty
                                                  Marquette University
    
                                 ihnp4!uwmacc!uwvax!uwmcsd1!marque!dennisf

porter@cbmvax.cbm.UUCP (Jeff Porter) (04/22/86)

> 
> 	If anyone has ever considered buying a modem for Commodore's micros,
> I can highly recommend the new 1670.  The software that comes with it (such
> as emulators, terminal programs, etc.) are invaluable and the near
> Hayes-compatibility make the 1200 bps modem a required peripheral (I live in
> a freshmen dorm, so my modem watches my phone line at night for prank calls).
> 	My modem, however, has a problem.  You see, it's quite incon-
> siderate.  It works just fine if my disk drive is turned on while I
> use my modem.  That's its trick.  When I think it's going fine and turn
> the disk drive off for the night, the modem becomes nasty if I want to
> dial out ("ATD...").  After the modem dials the number, it waits no more
> than a half second when SUDDENLY it spits out a bunch of loud glitches,
> mostly x's, which knock me off the line!!  How obnoxious!
> 	I've tried ATZ and ATS7=10 to stop the cruelty, but they do 
> nothing.  I wrote to Commodore Customer "Support" and all I got
> was an ad and a free sample of Commodore Microcomputer Magazine
> (Perhaps I should complain monthly?).  The only way I've found that
> works is to turn the 1541 back on, but I don't want to do that.
> 	Does anyone have any suggestions?  Does Commodore service the
> equipment?  Is there something inside that I can fix?  Repair?  Advice
> or instructions would be greatly appreciated.
>    
>                                                 Dennis Flaherty
>                                                   Marquette University
>     
>                                  ihnp4!uwmacc!uwvax!uwmcsd1!marque!dennisf

Dennis,

Your 1670 is working just fine.  The problem is that you are turning
off your disk drive.  The disk and the modem share the same reset line,
and when you turn your disk off, it pulls down the reset line on the
modem.  Well, it doesn't pull it down all the way, and hence the modem
gets upset - being half way between reset and not reset.

You have the following choices:

1. Turn everything OFF when not in use.  The obvious choice.

2. Keep everything ON when not in use.  This means the disk drive too,
but I imagine that you want to keep the drive from overheating.

Therefore we offer choice 3:

3. Before turning off your disk drive, unplug the serial connector,
and then turn off the disk drive.  This way, your disk stays nice and
cool and your modem doesn't get upset.

Personally I recommend choice 1.  I hope this helps.


Jeff "Mr. Modem" Porter     Commodore Engineering   ihnp4!cbmvax!porter

PS: Thanks for the compliment on the 1670.

ugbowen@sunybcs.UUCP (Devon Bowen) (04/22/86)

In article <410@marque.UUCP>, dennisf@marque.UUCP (flaherty) writes:
> 
> 	My modem, however, has a problem.  You see, it's quite incon-
> siderate.  It works just fine if my disk drive is turned on while I
> use my modem.  That's its trick.  When I think it's going fine and turn
> the disk drive off for the night, the modem becomes nasty if I want to
> dial out ("ATD...").  After the modem dials the number, it waits no more
> than a half second when SUDDENLY it spits out a bunch of loud glitches,
> mostly x's, which knock me off the line!!  How obnoxious!

I'm certainly not an expert on cbm hardware, but I know I can't turn off
my disk drive while my printer is printing. Even though they are not
related. It has something to do with the random power surges (?) present
when turning the system on or off send signals to the computer that
all hardware is turned off. Maybe your modem problem is related to this.
(Like I say, I'm no expert.)

What do you mean by "near Hayes compatible"? I'm in the market for a 1200
baud modem and would like Hayes compatibility.


                                      Devon E
                                      University of Buffalo

dennisf@marque.UUCP (flaherty) (04/22/86)

> 
> Your 1670 is working just fine.  The problem is that you are turning
> off your disk drive.  The disk and the modem share the same reset line,
> and when you turn your disk off, it pulls down the reset line on the
> modem.  Well, it doesn't pull it down all the way, and hence the modem
> gets upset - being half way between reset and not reset.
> 
> You have the following choices:
> 
> 1. Turn everything OFF when not in use.  The obvious choice.
> 
> 2. Keep everything ON when not in use.  This means the disk drive too,
> but I imagine that you want to keep the drive from overheating.
> 
> Therefore we offer choice 3:
> 
> 3. Before turning off your disk drive, unplug the serial connector,
> and then turn off the disk drive.  This way, your disk stays nice and
> cool and your modem doesn't get upset.
> 
> Personally I recommend choice 1.  I hope this helps.
> 
> 
> Jeff "Mr. Modem" Porter     Commodore Engineering   ihnp4!cbmvax!porter
> 
> PS: Thanks for the compliment on the 1670.

Jeff,
	Thanks a lot for answering!  Much more efficient than writing to 
Commodore Cust. Supp.  Actually I can't do choice #1 because the 1670
gets turned on when I turn the whole system on.  I load my vt52 emulator
from disk, so it has to come on with the modem.  But suggestion #3 should
work, and for once I can DO something.  And I know I don't have a defective
modem.  Now I can keep someone's phone ringing at 12:30 a.m. with a command
from a certain joystick on an extension cord by my bed.  You should see
how effective one ring is in getting others to turn down their stereos...
   "ooops... the phone's ringing... turn the volume down, quick..."
						Dennis Flaherty
						Marquette University
                                ihnp4!uwvax!uwmacc!uwmcsd1!marque!dennisf
					(note the correction ^)

		smart modems make hackers invulnerable at night...

	

porter@cbmvax.cbm.UUCP (Jeff Porter) (04/26/86)

> I'm certainly not an expert on cbm hardware, but I know I can't turn off
> my disk drive while my printer is printing. Even though they are not
> related. It has something to do with the random power surges (?) present
> when turning the system on or off send signals to the computer that
> all hardware is turned off. Maybe your modem problem is related to this.
> (Like I say, I'm no expert.)

The disk is pulling down the reset line, and the printer sits in a
continuously reset state.

> 
> What do you mean by "near Hayes compatible"? I'm in the market for a 1200
> baud modem and would like Hayes compatibility.

I don't support ALL of the S registers, other than that, the 1670 hangs
up the phone automatically after getting a +++.  Most other Hayes
modems, you must then issue a ATH to hang up.  I don't have ALL of the
DIP switch settings, but these are available through software.  It
comes bundled with a nice VT100 program for the 128 in 80 columns.
Noise immunity is VERY good.  Compact design.  Commodore price.

Jeff Porter
Commodore Engineering