Difference between revisions of "20ma current loop to RS-232 conversion"
 (Added detail of tty - RS232 board and terminal strips.)  | 
				 (→Schematic 1.1:  added sub section headings)  | 
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[[File:TTY RS-232 Back.png|400px]]  | [[File:TTY RS-232 Back.png|400px]]  | ||
| − | ==  | + | ==Additional Resources==  | 
| + | * Helpful article, [http://www.vintagecomputer.net/teletype101.cfm Teletype 101] from vintagecomputer.net  | ||
* Another circuit. From [[http://altairclone.com/teletype.htm Altairclone]] Specifically designed to fit in a Teletype model 33 using only a 12vdc wall wart for power.  | * Another circuit. From [[http://altairclone.com/teletype.htm Altairclone]] Specifically designed to fit in a Teletype model 33 using only a 12vdc wall wart for power.  | ||
| − | * Another [https://www.circuitlab.com/circuit/mnartk/screenshot/1024x768/ circuit] I found referenced on the greenkeys email list    | + | * Another [https://www.circuitlab.com/circuit/mnartk/screenshot/1024x768/ circuit] I found referenced on the greenkeys email list  | 
==My ASR hookup==  | ==My ASR hookup==  | ||
I built the circuit described above from the altairclone site. I found the Teletype 101 article helpful for identifying the proper terminal strip locations. The interface works. I set baud to 110, with 7 bits and 'mark' parity in TeraTerm on a windows 8 notebook with a Gigaware USB<> serial convereter.  | I built the circuit described above from the altairclone site. I found the Teletype 101 article helpful for identifying the proper terminal strip locations. The interface works. I set baud to 110, with 7 bits and 'mark' parity in TeraTerm on a windows 8 notebook with a Gigaware USB<> serial convereter.  | ||
| + | ===Schematic 1.1===  | ||
| + | From the original schematic at altairclone I added ASR terminal strip location numbers.  | ||
| + | |||
| + | [[File:RS-232 to ASR-33 Teletype Interface Schematic v1.1.jpg]]  | ||
| + | ===Wiring legend===  | ||
<source lang="text">  | <source lang="text">  | ||
| − | Signal   | + |                                screw        wire              schematic  | 
| + | Signal                        terminal      color             connection  | ||
| + | (Teletype 101 nomenclature)   (on ASR)      (mine)          (altair clone nomenclature)    | ||
---------------------------------------------------------------------  | ---------------------------------------------------------------------  | ||
| − | Transmitted data send (+)   | + | Transmitted data send (+)        7          orange          Data to Teletype +  | 
| − | Transmitted data return (-)   | + | Transmitted data return (-)      6          brown           Data to Teletype -  | 
| − | Received data send (+)   | + | Received data send (+)           4          red             Data from Teletype +  | 
| − | Received data return (-)   | + | Received data return (-)         3          black           Data from Teletype -  | 
</source>  | </source>  | ||
| − | + | ===Image details===  | |
[[File:My Altairclone TTY-RS232 Interface.png|600px]]  | [[File:My Altairclone TTY-RS232 Interface.png|600px]]  | ||
[[File:Teletype Model 33 ASR terminal block.png|600px]]  | [[File:Teletype Model 33 ASR terminal block.png|600px]]  | ||
| Line 31: | Line 39: | ||
[[Category:Various]]  | [[Category:Various]]  | ||
[[Category:Teletype]]  | [[Category:Teletype]]  | ||
| + | [[Category:Operational]]  | ||
Latest revision as of 09:36, 21 August 2015
Contents
20ma current loop <> RS-232 conversion
Vintage PCB
Dig this crazy circuit board man! Still in it's original packaging from Hobby World Electronics in Northridge California.
Additional Resources
- Helpful article, Teletype 101 from vintagecomputer.net
 - Another circuit. From [Altairclone] Specifically designed to fit in a Teletype model 33 using only a 12vdc wall wart for power.
 - Another circuit I found referenced on the greenkeys email list
 
My ASR hookup
I built the circuit described above from the altairclone site. I found the Teletype 101 article helpful for identifying the proper terminal strip locations. The interface works. I set baud to 110, with 7 bits and 'mark' parity in TeraTerm on a windows 8 notebook with a Gigaware USB<> serial convereter.
Schematic 1.1
From the original schematic at altairclone I added ASR terminal strip location numbers.
Wiring legend
                               screw        wire              schematic
Signal                        terminal      color             connection
(Teletype 101 nomenclature)   (on ASR)      (mine)          (altair clone nomenclature)  
---------------------------------------------------------------------
Transmitted data send (+)        7          orange          Data to Teletype +
Transmitted data return (-)      6          brown           Data to Teletype -
Received data send (+)           4          red             Data from Teletype +
Received data return (-)         3          black           Data from Teletype -
