20ma current loop to RS-232 conversion - Revision history

Jeffa: /* Schematic 1.1 */ added sub section headings

2015-08-21T09:36:08Z

‎Schematic 1.1: added sub section headings

Jeffa: /* My ASR hookup */ Added v1.1 schematic with my terminal strip numbers. wire legend nomenclature origins

2015-08-21T09:33:17Z

‎My ASR hookup: Added v1.1 schematic with my terminal strip numbers. wire legend nomenclature origins

Jeffa: /* My ASR hookup */ Add schematic connection column to wire legend

2015-08-21T09:08:50Z

‎My ASR hookup: Add schematic connection column to wire legend

Jeffa: /* Other resources */ renamed to Additional

2015-08-21T08:43:50Z

‎Other resources: renamed to Additional

Jeffa: /* other resources */

2015-08-21T00:13:09Z

‎other resources

Jeffa: Add Teletype 101 link.

2015-08-21T00:12:47Z

Add Teletype 101 link.

Jeffa: Added detail of tty - RS232 board and terminal strips.

2015-08-21T00:09:55Z

Added detail of tty - RS232 board and terminal strips.

Jeffa: Add my terminal strip colors

2015-08-20T18:11:35Z

Add my terminal strip colors

Jeffa: adding more resources. Schematic at circuitlab

2015-08-15T20:29:08Z

adding more resources. Schematic at circuitlab

Jeffa: Initial creation

2015-08-07T20:49:42Z

Initial creation

New page

=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.

[[File:TTY RS-232 Front.png|400px]]
[[File:TTY RS-232 Back.png|400px]]

==other resources==
* 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.

[[Category:Various]]

@@ Line 20: / Line 20: @@
 [[File:RS-232 to ASR-33 Teletype Interface Schematic v1.1.jpg]]
 <source lang="text">
                                 screw        wire              schematic
@@ Line 31: / Line 32: @@
 Received data return (-)         3          black           Data from Teletype -
 </source>
+===Image details===
 [[File:My Altairclone TTY-RS232 Interface.png|600px]]
 [[File:Teletype Model 33 ASR terminal block.png|600px]]

@@ Line 16: / Line 16: @@
 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.
 <source lang="text">
-                             screw       my wire          schematic
+                               screw        wire              schematic
-Signal                      terminal      color           connection
+Signal                        terminal      color             connection
 ---------------------------------------------------------------------
-Transmitted data send (+)      7          orange          Data to Teletype +
+Transmitted data send (+)        7          orange          Data to Teletype +
-Transmitted data return (-)    6          brown           Data to Teletype -
+Transmitted data return (-)      6          brown           Data to Teletype -
-Received data send (+)         4          red             Data from Teletype +
+Received data send (+)           4          red             Data from Teletype +
-Received data return (-)       3          black           Data from Teletype -
+Received data return (-)         3          black           Data from Teletype -
 </source>

@@ Line 17: / Line 17: @@
 <source lang="text">
-Signal                      screw terminal          my wire color
+                             screw       my wire          schematic
 ---------------------------------------------------------------------
-Transmitted data send (+)      7          orange
+Transmitted data send (+)      7          orange          Data to Teletype +
-Transmitted data return (-)    6          brown
+Transmitted data return (-)    6          brown           Data to Teletype -
-Received data send (+)         4          red
+Received data send (+)         4          red             Data from Teletype +
-Received data return (-)       3          black
+Received data return (-)       3          black           Data from Teletype -
 </source>
@@ Line 32: / Line 33: @@
 [[Category:Various]]
 [[Category:Teletype]]

@@ Line 8: / Line 8: @@
 [[File:TTY RS-232 Back.png|400px]]
-==Other resources==
+==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.

@@ Line 9: / Line 9: @@
 ==other resources==
 * 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
 ==My ASR hookup==