IbmPosDisplay

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Project IbmPosDisplay
Status Initializing
Contact bertrik
Last Update 2014-03-20

In this project, an old IBM point-of-sale (POS) display is reverse engineered to display arbitrary text. The goal of this project is not entirely clear.

The display in question contains two rows of 20 characters each. The characters on the display are of the VFD type, in blue/cyan.

Interface

The electrical interface to the display consists of 4 wires, probably an RS485 interface, possibly:

  • ground
  • data A (inverting), D-
  • data B (non-inverting), D+
  • power (12V) - red

A very simple RS232-to-RS485 conversion can be done by simply biasing the inverting data pin (data A) to half the supply voltage, and connecting the RS232 data line directly to the non-inverting data pin (data B).

TODO

  • Are we really sure this it has an RS485 interface? (where did that idea come from?)
  • Figure out baud rate
  • Write software to control the display

External links

Possible protocol descriptions:
{"cc_re__cc_re__cc_by_sa_3_0": ["ent link to this revision of the page\">Permanent link</a></li><li id=\"t-info\"><a href=\"/index.php?title=IbmPosDisplay&amp;action=info\" title=\"More information about this page\">Page information</a></li><li id=\"t-smwbrowselink\"><a href=\"/Special:Browse/IbmPosDisplay\" rel=\"smw-browse\">Browse properties</a></li>\t\t\t\t\t</ul>\n\t\t\t\t\t\t\t</div>\n\t\t</div>\n\t\t\t\t</div>\n\t\t</div>\n\t\t<div id=\"footer\" role=\"contentinfo\">\n\t\t\t\t\t\t\t<ul id=\"footer-info\">\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-info-copyright\">Content is available under <a class=\"external\" rel=\"nofollow\" href=\"http://creativecommons.org/licenses/by-sa/3.0/\">Creative Commons Attribution Share Alike</a> unless otherwise noted.</li>\n\t\t\t\t\t\t\t\t\t</ul>\n\t\t\t\t\t\t\t<ul id=\"footer-places\">\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-privacy\"><a href=\"/RevSpace:Privacy_policy\" title=\"RevSpace:Privacy policy\">Privacy policy</a></li>\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-about\"><a href=\"/RevSpace:About\" title=\"RevSpace:About\">About RevSpace</a></li>\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-disclaimer\"><a href=\"/RevSpace:General_disclaimer\" title=\"RevSpace:General disclaimer\">Disclaimers</a", "\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-privacy\"><a href=\"/RevSpace:Privacy_policy\" title=\"RevSpace:Privacy policy\">Privacy policy</a></li>\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-about\"><a href=\"/RevSpace:About\" title=\"RevSpace:About\">About RevSpace</a></li>\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-places-disclaimer\"><a href=\"/RevSpace:General_disclaimer\" title=\"RevSpace:General disclaimer\">Disclaimers</a></li>\n\t\t\t\t\t\t\t\t\t</ul>\n\t\t\t\t\t\t\t\t\t\t<ul id=\"footer-icons\" class=\"noprint\">\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-copyrightico\">\n\t\t\t\t\t\t\t<a href=\"http://creativecommons.org/licenses/by-sa/3.0/\"><img src=\"/resources/assets/licenses/cc-by-sa.png\" alt=\"Creative Commons Attribution Share Alike\" width=\"88\" height=\"31\"/></a>\t\t\t\t\t\t</li>\n\t\t\t\t\t\t\t\t\t\t\t<li id=\"footer-poweredbyico\">\n\t\t\t\t\t\t\t<a href=\"https://www.semantic-mediawiki.org/wiki/Semantic_MediaWiki\"><img src=\"/extensions/SemanticMediaWiki/includes/../res/images/smw_button.png\" alt=\"Powered by Semantic MediaWiki\" width=\"88\" height=\"31\"/></a>\t\t\t\t\t\t</li>\n\t\t\t\t\t\t\t\t\t</ul>\n\t\t\t\t\t\t<div style=\"clear:both\"></div>\n\t\t</div>\n\t\t<script>window.RLQ = window"], "copyright__copyright__copyright": ["ata A (inverting), D-\n  \u2022 data B (non-inverting), D+\n  \u2022 power (12V) - red\n\nA very simple RS232-to-RS485 conversion can be done by simply biasing the inverting data pin (data A) to half the supply voltage, and connecting the RS232 data line directly to the non-inverting data pin (data B).\n\nTODO\n\n  \u2022 Are we really sure this it has an RS485 interface? (where did that idea come from?)\n  \u2022 Figure out baud rate\n  \u2022 Write software to control the display\n\nExternal links\n\nPossible protocol descriptions:", "ata A (inverting), D-\n  \u2022 data B (non-inverting), D+\n  \u2022 power (12V) - red\n\nA very simple RS232-to-RS485 conversion can be done by simply biasing the inverting data pin (data A) to half the supply voltage, and connecting the RS232 data line directly to the non-inverting data pin (data B).\n\nTODO\n\n  \u2022 Are we really sure this it has an RS485 interface? (where did that idea come from?)\n  \u2022 Figure out baud rate\n  \u2022 Write software to control the display\n\nExternal links\n\nPossible protocol descriptions:", "ata A (inverting), D-\n  \u2022 data B (non-inverting), D+\n  \u2022 power (12V) - red\n\nA very simple RS232-to-RS485 conversion can be done by simply biasing the inverting data pin (data A) to half the supply voltage, and connecting the RS232 data line directly to the non-inverting data pin (data B).\n\nTODO\n\n  \u2022 Are we really sure this it has an RS485 interface? (where did that idea come from?)\n  \u2022 Figure out baud rate\n  \u2022 Write software to control the display\n\nExternal links\n\nPossible protocol descriptions:"]}