Hey Mike.
I took apart the cable we use and this is the setup:
db25         de9
----------------------
1  ------   shield
2   ------   2
3   ------   3
7   ------   5
4,5          1,4,6
6,8,20
simon
On 23-02-15 04:06, Mike Loewen wrote:
      Well, I finally got back to the GNT 4601, and
I'm still unable to
 get it to work correctly.  I'm using the following (null) cable,
 connected to the DCE connector (the one on the corner):
 DE9        DB25
 --------------------
 1        20
 2        2
 3        3
 4        6,8
 5        7
 6        20
 7        5
 8        4
     On the GNT 4601, FDX, DC Codes Off.
     On the Linux side:
 stty -F /dev/ttyS0 -a
 speed 1200 baud; rows 0; columns 0; line = 0;
 intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
 eol2 = <undef>; swtch = <undef>; start = ^Q;
 stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O;
 min = 1; time = 0;
 -parenb -parodd cs8 -hupcl -cstopb cread clocal crtscts
 -ignbrk brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl -ixon
 -ixoff -iuclc -ixany imaxbel -iutf8
 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0
 vt0 ff0
 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop
 -echoprt echoctl echoke
     With these settings, nothing happens when I send chars to the punch
 (cat > /dev/ttyS0).  If I turn RTS/CTS off (-crtscts), the punch runs
 and chars are punched, although I'm certain not all of them.
     If I try and read a tape from the punch (cat /dev/ttyS0, press the
 Read button on the punch), I get nothing on the Linux side.  The tape
 reads a short burst every time I press Read, but nothing ever shows up
 on the terminal.
     I'm beginning to the the 4601 has a problem, at least with the
 reader. I've tried to duplicate a tape in Local mode, and nothing seems
 to be read and nothing gets punched.
     Feeling very frustrated.
 On Fri, 6 Feb 2015, Simon Claessen wrote:
  well I located the machine and it turns out that
the connector closest
 to the corner is used. we made a nullmodem cable going to a db9
 connector and we grab the papertapes on a 600/1200 baud setting as
 handshaking is somewhat broken on the pc side and we want to be shure
 to get al the bits. :-)
 Our capture of pdp-8 tapes is here:
 
https://github.com/Hack42/Museum/tree/master/Papertape
 On 02-02-15 16:05, Simon Claessen wrote:
   we have a 4601 and i've made a nullmodem
cable, but at the moment, I
  cant to remember on which connector it went. i think is was the
  connector going to the terminal, not the computer one. via the dip
  switches on the bottom you can preset three speed settings,
 available at
  a switch on the top. I will take a look wednesday when i'm back at the
  museum.
  simon
  On 02-02-15 05:43, Mike Loewen wrote:
       I have a box of old HP paper tapes to read,
and am having an 
 awful
   time trying to build the right serial cable to
connect a GNT-4601
  reader/punch to a Linux PC.  Does anyone have a known good cable 
 diagram
 >  and stty settings that will work?  Thank.
 > > >  Mike Loewen                mloewen at cpumagic.scol.pa.us
 >  Old Technology                
http://q7.neurotica.com/Oldtech/
 > 
 --
 Met vriendelijke Groet,
 Simon Claessen
 drukknop.nl
 
 Mike Loewen                mloewen at cpumagic.scol.pa.us
 Old Technology                
http://q7.neurotica.com/Oldtech/