[comp.sys.cbm] C128-1571-1541-1525 combination hangs serial bus?

stephenc@tekgen.TEK.COM (Stephen Coan ) (05/04/88)

I have been having a problem ever since I got my C128 with a 1571 drive to
replace my aging 64.  The problem is that when I hook up both drives and
the printer to either the 64 or the 128, I cannot use the printer, or the
drive at address 9.  

I have hardware changed the 1541 to be at address 9.  

The printer is a Sekosha C100 (1525 compaitble I believe) and works as a
1525 with GEOS.

Either both disk drives, or either disk drive and the printer will work
as long as one disk or the printer is powered off/disconnected.  This is
true with GEOS or in a normal mode of operation.

Is this a normal situation or is this unusual?  Does anyone else have this
problem?  Any help would be appreciated.

NOTE:  The 1571 and C128 are a couple of years old, in case this is relevant
at all.

Thanks in advance for any help.
-- 

			Steve Coan
			tektronix!tekgen!stephenc
			(503) 627-1794

dwl10@amdahl.uts.amdahl.com (Dave Lowrey) (05/05/88)

In article <
>I have been having a problem ever since I got my C128 with a 1571 drive to
>replace my aging 64.  The problem is that when I hook up both drives and
>the printer to either the 64 or the 128, I cannot use the printer, or the
>drive at address 9.  
>
>I have hardware changed the 1541 to be at address 9.  
>
>The printer is a Sekosha C100 (1525 compaitble I believe) and works as a
>1525 with GEOS.
>
>Either both disk drives, or either disk drive and the printer will work
>as long as one disk or the printer is powered off/disconnected.  This is
>true with GEOS or in a normal mode of operation.
>
>Is this a normal situation or is this unusual?  Does anyone else have this
>problem?  Any help would be appreciated.
>
>NOTE:  The 1571 and C128 are a couple of years old, in case this is relevant
>at all.
>
>Thanks in advance for any help.
>-- 
>
>			Steve Coan
>			tektronix!tekgen!stephenc
>			(503) 627-1794

I had the same problem with my 64/1541/Cardco printer interface.
 
Turned out to be a C64 power supply problem. Don't know what whas wrong
with it, but when I replaced it, everything worked fine!


-- 
-------------------------------------------------------------------

                  "Familiarity breeds attempt"

                          Dave Lowrey
                          Amdahl Corp.
                          Houston, Texas
                          (713)-850-8828
                         ...!{ihnp4,cbosgd,hplabs,oliveb}!amdahl!dwl10

[ The opinions expressed <may> be those of the author and not necessarily
  those of his most eminent employer. ]

elg@killer.UUCP (Eric Green) (05/08/88)

in article <2868@tekgen.TEK.COM>, stephenc@tekgen.TEK.COM (Stephen Coan ) says:
> replace my aging 64.  The problem is that when I hook up both drives and
> the printer to either the 64 or the 128, I cannot use the printer, or the
> drive at address 9.  
>
> The printer is a Sekosha C100 (1525 compaitble I believe) and works as a
> 1525 with GEOS.

The Seikosha is probably the problem. Big-name printer manufacturers have been
notably unuccessful in their attempts to duplicate the Commodore serial bus
routines (probably because timing for those routines is so flaky.... . e.g.
the notorious four NOP's for the output-a-byte routine). Try borrowing someone
else's printer temporarily, and see if that solves the problem.

--
    Eric Lee Green  elg@usl.CSNET    Snail Mail P.O. Box 92191        
    ihnp4!killer!elg                 Lafayette, LA 70509              
"Is a dream a lie that don't come true, or is it something worse?"