If you connect a western keyboard to the earliest PS/55 and PS/55 N23 SX notes, the keyboard mappings are all messed up. Here is a rough map of what key is mapped to what real keypress:
| F1 | ^Z | 1 | 3 | Q | E | CAPS | K |
| F2 | G | 2 | 8 | W | I | A | |
| F3 | F | 3 | 4 | E | R | S | |
| F4 | V | 4 | 7 | R | U | D | 5 |
| F5 | X | 5 | H | T | J | F | 6 |
| F6 | BACKSLASH | 6 | ESCAPE | Y | A | G | M |
| F7 | 7 | 1 | U | Q | H | Z | |
| F8 | 8 | 6 | I | P | J | ||
| F9 | BACKSLASH | 9 | O | RIGHT CURSOR | K | - | |
| F10 | 2 | 0 | 9 | P | O | L | |
| F11 | - | Z | backslash | L | + | ||
| F12 | ^ | ' | { | ; | * | . | |
| NEXT TO END | F8 | YEN SYMBOL | W | ENTER | } | ||
| GREEN BUTTON BOTTOM LEFT | ENTER | To right of YEN Symbol | S | TAB | D | RIGHT CONTROL | LEFT ARROW |
| LEFT SHIFT | UP CURSOR |
| Z | |
| X | |
| C | B |
| V | N |
| B | Y |
| N | TAB OR DOWN CURSOR |
| M | |
| < | / |
| RIGHT CONTROL | LEFT CURSOR |
TOP RIGHT AND DOWN ONE (UNKNOWN JAPANESE CHARACTER) = F8