Search Posts:

CHIP connection to serial terminal

View Entire Thread

Return to Threads

SHARE
  by Bill Degnan - 01/14/2017 20:23
Don't want to be stuck using SSH or the tiny Pocket to access simH? Add a serial terminal. A vintage serial terminal to access simH is the way to go.

Here are few notes These directions work for both the Pocket CHIP or bare CHIP.

In addition to the Pocket CHIP I also have a CHIP with an HDMI "DIP" add-on board whose Debian build does not default to support a USB as serial port. For the bare CHIP I decided to set it to boot into the CLI and scan for a serial connection via USB as the io device .

First I needed to confirm the USB to serial cable driver loads when detected, and the default baud rate of the tty USB is 9600. Also I needed to activate the USB port to be ready upon boot.

To start, boot your CHIP with the USB ro serial cable attached. Put a null modem adapter between your CHIP and the terminal.

You need to know the name the machine uses for the USB "tty" port This is what the system will call your USB to Serial connection:

$ dmesg | grep tty

(look for ttyUSB0, 1, 2, etc.in the output make a note of the name used)

Do you have the driver loaded and set for your USB to Serial cable? Here is a bash script that you can use, I found one that works and named it testUSB.sh, and put it in the /dev directory.

#!/bin/bash

for sysdevpath in $(find /sys/bus/usb/devices/usb*/ -name dev); do
(
syspath="${sysdevpath%/dev}"
devname="$(udevadm info -q name -p $syspath)"
[[ "$devname" == "bus/"* ]] && continue
eval "$(udevadm info -q property --export -p $syspath)"
[[ -z "$ID_SERIAL" ]] && continue
echo "/dev/$devname - $ID_SERIAL"
)
done

The output I got was:
/dev/ttyUSB0 - Prolific_Technology_Inc._USB-Serial_Controller
(yours may vary, depending whether you use the Prolific USB to serial able or some other.)
-----------------------------
If you don't get a response similar to this, you need to install the driver for your cable. Before you do that reboot with the cable installed, maybe the OS will recognize it.

Assuming you have a driver loaded.....

Run a command to check the status of your USB serial port. My CHIPs both use ttyUSB0 so the command is:
$ stty -F /dev/ttyUSB0

(the output will tell you the baud rate to set the terminal on the other end, etc)

If changes are needed, such as baud rate...
$ stty -F /dev/ttyUSB0 9600

After confirming one has the driver loaded and the correct serial connection settings, check the status of the USB to serial port to see if it's actively monitoring for serial console connections inbound:

systemctl status serial-getty@ttyUSB0.service

If it's not active, turn it on!

sudo systemctl start serial-getty@ttyUSB0.service

Test. Hopefully the result is a login prompt on the serial terminal.

Have fun!

If you want this USB Serial console to be available on boot, make it permanent:
systemctl enable serial-getty@ttyUSB0.service

Reply

Resources:


Buy a Commodore Computer Poster

Popular Topics and FAQs


  • Commodore B Series Tips and Tricks
  • Aerocomp TRS 80 M 1 Expansion Unit DDC
  • Items Wanted
  • Lobo Max 80
  • Zenith Z-19-CN
  • Prototype PET 2001 photo
  • Using Toggle Switches to Analyze Memory
  • Commodore Disk Archive Project
  • PET 2001 Prototype at Gametronics 1977
  • Jim Butterfield Photo
  • IMSAI 8080 With Processor Tech. Cutter
  • Secrecy is the keystone of all tyranny
  • Cromemco System Three
  • Northstar Horizon - Boot Problem
  • Computer History and Restoration Links
  • Commodore BX-256-80 - 8088 Co-processor
  • S-100 board testing with Z-80 ICE
  • Donner 3500 - an early portable computer
  • Digital (DEC) PDP 11/05 NC Assembly
  • Univac 1219 rescue
  • IMSAI 1.4 BASIC vs. MITS 8K BASIC
  • Fido BBS listing node list 6-13-1986
  • PDP 8e
  • MITS 88-2 SIO (2SIO) for BASIC
  • Visual Technology Inc Model 1050
  • Amiga 2500 Restoration
  • The Evolution Of IBM Computers
  • Replacement teletype print hammer head
  • Archiving and Copying Software 101
  • Computers Built 1940 - 1950
  • CBM B-520 (a.k.a B256-80 or B500 256)
  • RCA COSMAC Microkit
  • Commodore 64K C-116 Mods
  • MITS 8800b Turnmon 9600 baud
  • Catweasel, 8in and 5 1/4
  • Raspberry Pi as Gateway to Internet
  • Digital PDP11 late 1969 early 1970
  • PDP 11/40 72 inch cabinet model
  • PDP 11/40 Industrial 11 model
  • Digitial MicroVAX 3100 30 System
  • Digital VAX 4000-200
  • Commodore 64 / 1541 DRIVEKNOCK
  • Booting the System Using RL02 drive
  • PACS: Reflections by Kathleen Mauchly
  • Tele-Graphic Computer Systems Inc.
  • Commodore B Series SID Jukebox?
  • Installing Core into PDP 11/40
  • Setting Up OpenVMS 7.1 DNS CLERK
  • Felt-Tarrant Comptometer Model J
  • NextStation Color
  • Digital Rainbow (PC100-B2)
  • 1970 Compusad Compulogical Tutor
  • Archiving Papertapes Using DSI NC 2400
  • 1976 P.C.C. Features the MAI JOLT 6502
  • 1961 Beckman DEXTIR Computer
  • UNIVAC 1 and UNIVAC File Computer 1
  • Past Issues:


    tcf 2008 digital pdp8 sn1158 front panel c

    This image was selected at random from the archive. Click image for more photos and files from this set.