Discussion:
HP48GX cable transfer in Linux?
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f***@gmail.com
2020-02-26 19:48:39 UTC
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Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac running Ubuntu Linux with a serial DB9 to usb adapter; the adapter is recognized and properly showing under Linux as /dev/ttyUSB0 (I even connected a led to the TX line and flashed it from python, so signal is ok).
But had ZERO success in trying to communicate with HP48GX from kermit, minicom and hptalx 1.3.1.
I used the pinout schematics from here:
https://www.educalc.net/1199484.page

Of course I connected the TX from pc's DB9 to RX of HP48GX and viceversa but tried all methods (kermit, xmodem, server mode) to no avail.Always timeout error on both ends (so there is some signal/cabling issue imho).

Did anyone have success with this setup?

thanks in advance

juan
olaf
2020-02-26 20:23:39 UTC
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Post by f***@gmail.com
Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac
My last Apple was a ][+,
Post by f***@gmail.com
Did anyone have success with this setup?
...but datatransfer to a normal linux computer with kermit was working
when I used it last time a few year back.

Do you have correct udev rules so a user can use the port?

Olaf
f***@gmail.com
2020-02-29 01:30:07 UTC
Permalink
Post by olaf
Post by f***@gmail.com
Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac
My last Apple was a ][+,
Post by f***@gmail.com
Did anyone have success with this setup?
...but datatransfer to a normal linux computer with kermit was working
when I used it last time a few year back.
Do you have correct udev rules so a user can use the port?
Olaf
Hi Olaf, after your reply I chmod'ed to 777 /dev/ttyUSB0 but even running all the tools as root yielded no results.
Im suspecting the HP has a hardware problem in the serial port; otherwise Im looking to borrow an old pc motherboard with a built-in serial DB-9 port and try there.

Thanks!

juan
Eugene Nine
2020-03-02 13:51:34 UTC
Permalink
Post by f***@gmail.com
Post by olaf
Post by f***@gmail.com
Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac
My last Apple was a ][+,
Post by f***@gmail.com
Did anyone have success with this setup?
...but datatransfer to a normal linux computer with kermit was working
when I used it last time a few year back.
Do you have correct udev rules so a user can use the port?
Olaf
Hi Olaf, after your reply I chmod'ed to 777 /dev/ttyUSB0 but even running all the tools as root yielded no results.
Im suspecting the HP has a hardware problem in the serial port; otherwise Im looking to borrow an old pc motherboard with a built-in serial DB-9 port and try there.
Thanks!
juan
You can test the pc side easy enough by putting a jumper wire between the Tx and Rx of your usb to serial adapter and see the echo of whatever you send out the port.

put a couple LED's between rx and gnd and tx and gnd and see if you get blinkinlights with activity.
f***@gmail.com
2020-03-03 19:00:30 UTC
Permalink
Post by Eugene Nine
Post by f***@gmail.com
Post by olaf
Post by f***@gmail.com
Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac
My last Apple was a ][+,
Post by f***@gmail.com
Did anyone have success with this setup?
...but datatransfer to a normal linux computer with kermit was working
when I used it last time a few year back.
Do you have correct udev rules so a user can use the port?
Olaf
Hi Olaf, after your reply I chmod'ed to 777 /dev/ttyUSB0 but even running all the tools as root yielded no results.
Im suspecting the HP has a hardware problem in the serial port; otherwise Im looking to borrow an old pc motherboard with a built-in serial DB-9 port and try there.
Thanks!
juan
You can test the pc side easy enough by putting a jumper wire between the Tx and Rx of your usb to serial adapter and see the echo of whatever you send out the port.
put a couple LED's between rx and gnd and tx and gnd and see if you get blinkinlights with activity.
yes and that works! That's why Im suspecting the problem is on the HP48GX side (if there's a voltage level missmatch between the serial connections that's out of my scope)
Eugene Nine
2020-03-30 17:50:15 UTC
Permalink
Post by f***@gmail.com
Post by Eugene Nine
Post by f***@gmail.com
Post by olaf
Post by f***@gmail.com
Hi, I recently got an HP48GX from a friend and tried to connect to my usb iMac
My last Apple was a ][+,
Post by f***@gmail.com
Did anyone have success with this setup?
...but datatransfer to a normal linux computer with kermit was working
when I used it last time a few year back.
Do you have correct udev rules so a user can use the port?
Olaf
Hi Olaf, after your reply I chmod'ed to 777 /dev/ttyUSB0 but even running all the tools as root yielded no results.
Im suspecting the HP has a hardware problem in the serial port; otherwise Im looking to borrow an old pc motherboard with a built-in serial DB-9 port and try there.
Thanks!
juan
You can test the pc side easy enough by putting a jumper wire between the Tx and Rx of your usb to serial adapter and see the echo of whatever you send out the port.
put a couple LED's between rx and gnd and tx and gnd and see if you get blinkinlights with activity.
yes and that works! That's why Im suspecting the problem is on the HP48GX side (if there's a voltage level missmatch between the serial connections that's out of my scope)
The HP doesn't quite meet rs232 spec of the full +/-12v but it close enough that it works most of the time.
I assume you changed the48 to use wire and not ir?

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