add README to Epson directory

epson/README.md

@@ -0,0 +1,45 @@
+Epson FX dot matrix printer fonts
+=================================
+
+This directory contains fonts for the Epson FX printers. While these
+were not extracted from original hardware or firmware, the have been
+checked carefully against matrices given in original documentation.
+The variants here correspond to different editions of the manual, as 
+referenced in the files.
+
+Should you however find any discrepancies with the sources references,
+or have access to other versions or sources of these fonts, please do get in
+touch.
+
+
+Character sets
+--------------
+
+The characters are stored in ROM in an ASCII-based order, with non-ASCII
+characters filling the positions of control characters. The lower 7-bit
+block contains the roman slant of the font, while the upper block has
+the italic slant.
+
+The printer supported different national character sets, which have some
+glyphs reassigned to different code points.
+
+The following code points differ:
+
+|       |`23`|`24`|`40`|`5b`|`5c`|`5d`|`5e`|`60`|`7b`|`7c`|`7d`|`7e`|
+|       |`a3`|`a4`|`c0`|`db`|`dc`|`dd`|`de`|`e0`|`fb`|`fc`|`fd`|`fe`|
+|-------|----|----|----|----|----|----|----|----|----|----|----|----|
+|US     |  # |  $ |  @ | [  |  \ |  ] |  ^ | \` |  { | \| |  } |  ~ |
+|Japan  |  # |  $ |  @ | [  |  ¥ |  ] |  ^ | \` |  { | \| |  } |  ~ |
+|France |  # |  $ |  à | °  |  ç |  § |  ^ | \` |  é |  ù |  è |  ¨ |
+|Germany|  # |  $ |  § | Ä  |  Ö |  Ü |  ^ | \` |  ä |  ö |  ü |  ß |
+|UK     |  £ |  $ |  @ | [  |  \ |  ] |  ^ | \` |  { | \| |  } |  ~ |
+|Denmark|  # |  $ |  @ | Æ  |  Ø |  Å |  ^ | \` |  æ |  ø |  å |  ~ |
+|Sweden |  # |  ¤ |  É | Ä  |  Ö |  Å |  Ü |  é |  à |  ö |  å |  ü |
+|Italy  |  # |  $ |  @ | °  |  \ |  é |  ^ |  ù |  à |  ò |  è |  ì |
+|Spain  |  ₧ |  $ |  @ | ¡  |  Ñ |  ¿ |  ^ | \` |  ¨ |  ñ |  } |  ~ |
+
+
+Notes:
+- The lower-7 bit mappings are similar but not identical to either the
+  ISO-646 variants or the DEC National Replacement Character Sets
+