Message-ID: <142@vaxwalle.UUCP>
Date: Fri, 6-Apr-84 13:50:28 EST
Article-I.D.: vaxwalle.142
Posted: Fri Apr  6 13:50:28 1984
Date-Received: Sun, 8-Apr-84 01:25:29 EST
Lines: 15

I am trying to use a 1200 baud modem ( a USR password ) with the 
C-64 using an RS232 adapter. The set up works fine at 300 baud ,
but at 1200 baud the computer gets mostly garbage on the screen.
 I tried the same modem on the same phone line to the same host
with an IBM and got no errors. I think that the c-64 kernal routine
that handles RS232 just can't keep up with 1200 baud. Maybe if I
turned off or slowed down the 60hz interrupt it would help. I have 
yet to try this.

Has anyone else found this to be a problem ? 

If there is a terminal program that works at 1200 baud , I would 
like to know.

  Thanks in advance.  

Message-ID: <2259@tektronix.UUCP>
Date: Wed, 18-Apr-84 01:00:23 EST
Article-I.D.: tektroni.2259
Posted: Wed Apr 18 01:00:23 1984
Date-Received: Fri, 13-Apr-84 08:28:30 EST
References: <142@vaxwalle.UUCP>
Organization: Tektronix, Beaverton OR
Lines: 21


   The C64 does have problems at 1200 baud. I have used both OMNI TERM and
Smart Terminal 64. In both cases transmission was successful; ie I could
login and execute commands; but the output was about 80% garbaged. The only
terminal package that comes close is UNIX TERM. With UNIX TERM I get about
2 or 3 errors per screen full of output. UNIX TERM does this  well by using a
non-standard bit time, rather than the timing provided by the Kernal.
This user rate is specified when the RS232 port is opened. The actual timing
constant is specified as the 3rd and 4th bytes of the file name. In BASIC
this would be: OPEN 2,2,0,chr$(0)+chr$(0)+chr$(60)+chr$(1). See the
programmers reference for details. The two byte constant used by UNIX TERM
is 316 ($13C). The one normally used by the Kernal is 317 ($13D).
   I have tried this with BASIC with mixed results; Better than just
using 1200 baud, but not acceptable reliability. I have sent for VIDTXT
for the 64 from compuserv. VIDTXT is also supposed to work reliably at 1200
baud, But I doubt that it will if it uses the C64's standard 1200 baud
timing.


Joel Swank
Tektronix, Beaverton OR