If you have stable at the issues, in particular when using a accelerator with a H5 A1 or B1 Revision board, it may have been fitted with 4.7K bus pullups (please check before ordering). If you experience stability issues then fitting this board should help alleviate the problems. There is no need to fit this board on the C1 series of boards. These boards come part assembled with the SMT resistor packs pre-installed. You need to fit the header strips yourself.
NOTE: You also need 2 header strips such as #0132.
Available until stock is exhausted.