Where can I find the coordinates of the 128 channel caps based on the 5% system defined by Oostenveld and Praamstra?
The positions in these caps come from the Oostenveld and Praamstra 5% system. See http://robertoostenveld.nl/electrode/ for background and for links to electrode coordinates in a variety of formats. Depending on what software you are using for analysis, we might be able to provide another file format. The Biosemi channel assignments (relating electrode labels to electrode sites in the Oostenveld and Praamstra nomenclature) are below:
| Chan1 | A1 | Fp1 |
| Chan2 | A2 | AFp1 |
| Chan3 | A3 | AF7 |
| Chan4 | A4 | AF3 |
| Chan5 | A5 | AFF5h |
| Chan6 | A6 | AFF1h |
| Chan7 | A7 | F9 |
| Chan8 | A8 | F7 |
| Chan9 | A9 | F5 |
| Chan10 | A10 | F3 |
| Chan11 | A11 | F1 |
| Chan12 | A12 | FFT9h |
| Chan13 | A13 | FFT7h |
| Chan14 | A14 | FFC5h |
| Chan15 | A15 | FFC3h |
| Chan16 | A16 | FFC1h |
| Chan17 | A17 | FT9 |
| Chan18 | A18 | FT7 |
| Chan19 | A19 | FC5 |
| Chan20 | A20 | FC3 |
| Chan21 | A21 | FC1 |
| Chan22 | A22 | FTT9h |
| Chan23 | A23 | FTT7h |
| Chan24 | A24 | FCC5h |
| Chan25 | A25 | FCC3h |
| Chan26 | A26 | FCC1h |
| Chan27 | A27 | T7 |
| Chan28 | A28 | C5 |
| Chan29 | A29 | C3 |
| Chan30 | A30 | C1 |
| Chan31 | A31 | TTP7h |
| Chan32 | A32 | CCP5h |
| Chan33 | B1 | CCP3h |
| Chan34 | B2 | CCP1h |
| Chan35 | B3 | TP9 |
| Chan36 | B4 | TP7 |
| Chan37 | B5 | CP5 |
| Chan38 | B6 | CP3 |
| Chan39 | B7 | CP1 |
| Chan40 | B8 | CPz |
| Chan41 | B9 | TPP7h |
| Chan42 | B10 | CPP5h |
| Chan43 | B11 | CPP3h |
| Chan44 | B12 | CPP1h |
| Chan45 | B13 | P9 |
| Chan46 | B14 | P7 |
| Chan47 | B15 | P5 |
| Chan48 | B16 | P3 |
| Chan49 | B17 | P1 |
| Chan50 | B18 | Pz |
| Chan51 | B19 | PPO9h |
| Chan52 | B20 | PPO5h |
| Chan53 | B21 | PPO1h |
| Chan54 | B22 | PO7 |
| Chan55 | B23 | PO3 |
| Chan56 | B24 | POz |
| Chan57 | B25 | PO9 |
| Chan58 | B26 | POO9h |
| Chan59 | B27 | O1 |
| Chan60 | B28 | POO1 |
| Chan61 | B29 | I1 |
| Chan62 | B30 | Ol1h |
| Chan63 | B31 | Oz |
| Chan64 | B32 | Iz |
| Chan65 | C1 | Fpz |
| Chan66 | C2 | Fp2 |
| Chan67 | C3 | AFp2 |
| Chan68 | C4 | AFz |
| Chan69 | C5 | AF4 |
| Chan70 | C6 | AF8 |
| Chan71 | C7 | AFF2h |
| Chan72 | C8 | AFF6h |
| Chan73 | C9 | Fz |
| Chan74 | C10 | F2 |
| Chan75 | C11 | F4 |
| Chan76 | C12 | F6 |
| Chan77 | C13 | F8 |
| Chan78 | C14 | F10 |
| Chan79 | C15 | FFC2h |
| Chan80 | C16 | FFC4h |
| Chan81 | C17 | FFC6h |
| Chan82 | C18 | FFT8h |
| Chan83 | C19 | FFT10h |
| Chan84 | C20 | FCz |
| Chan85 | C21 | FC2 |
| Chan86 | C22 | FC4 |
| Chan87 | C23 | FC6 |
| Chan88 | C24 | FT8 |
| Chan89 | C25 | FT10 |
| Chan90 | C26 | FCC2h |
| Chan91 | C27 | FCC4h |
| Chan92 | C28 | FCC6h |
| Chan93 | C29 | FTT8h |
| Chan94 | C30 | FTT10h |
| Chan95 | C31 | Cz |
| Chan96 | C32 | C2 |
| Chan97 | D1 | C4 |
| Chan98 | D2 | C6 |
| Chan99 | D3 | T8 |
| Chan100 | D4 | CCP2h |
| Chan101 | D5 | CCP4h |
| Chan102 | D6 | CCP6h |
| Chan103 | D7 | TPP8h |
| Chan104 | D8 | CP2 |
| Chan105 | D9 | CP4 |
| Chan106 | D10 | CP6 |
| Chan107 | D11 | TP8 |
| Chan108 | D12 | TP10 |
| Chan109 | D13 | CPP2h |
| Chan110 | D14 | CPP4h |
| Chan111 | D15 | CPP6h |
| Chan112 | D16 | TPP8h |
| Chan113 | D17 | P2 |
| Chan114 | D18 | P4 |
| Chan115 | D19 | P6 |
| Chan116 | D20 | P8 |
| Chan117 | D21 | P10 |
| Chan118 | D22 | PPO2h |
| Chan119 | D23 | PPO6h |
| Chan120 | D24 | PPO10h |
| Chan121 | D25 | PO4 |
| Chan122 | D26 | PO8 |
| Chan123 | D27 | PO10 |
| Chan124 | D28 | POO2 |
| Chan125 | D29 | O2 |
| Chan126 | D30 | POO10h |
| Chan127 | D31 | Ol2h |
| Chan128 | D32 | I2 |