== LK1,LK2,LK3 - Manufacturer ID ==
LK1,LK2,LK3 connect to [[8255|PPI]] Port B, Bit1-3. The links select the manufacturer name (which is displayed by the BIOS in the power-up message). These LKs exist on all CPC mainboards (in CPC Plus/GX4000 schematics they are named LK101,LK102,LK103). By default, LK1-LK3 are not installed (except, Amstrad). Other combinations are LK2 is installed in german Scheider [[Schneider]] models, and LK1+LK2 in australian [[Awa]] models).
== LK4 - Screen Refresh Rate ==