System/36 Twin-Ax decode help

alan at alanlee.org alan at alanlee.org
Sat Nov 30 22:59:14 CST 2019


 From some slef-progress and a few replies.. an update.

I've managed to figure out the rough framing of the TwinAx messages from 
primarily this document:

http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/5250_5251/SY31-0461-0_5251_Display_Station_Model_11_Maintenance_Information_Dec77.pdf

...where it talks about the commands and modifier bits.  However I'm 
missing a detailed command reference that covers basic stuff; for 
example the argument format to the SET MODE command, etc.  But it was 
enough to update the decoded output with tons more detail - here:

https://www.retrotronics.org/tmp/s36_ipl_twinax_decode_31nov19.zip

I 'think' this is enough to respin my break-out with a iCE40 and a ESP32 
for a true wireless interface.  I have a line-driver chip that is still 
coming in from Digikey this week that will let me try and talk to a 
InfoWindow II terminal as if I'm a midrange host - validating all my 
transmit logic.  Then I might put this project on the shelf for a while 
unless I can find more docs that explains the command further.

-Alan H

On 2019-11-30 18:38, alan--- via cctalk wrote:
> All,
> 
> I've recently scratched a curiosity itch on what it would take to build
> a multi-port Twin-Ax to WiFi bridge.


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