== 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 /Costdown schematics they are named LK101,LK102,LK103). By default, LK1-LK3 are not installed ([[Amstrad]]). Other combinations are LK2 installed in german [[Schneider]] models, and LK1+LK2 in australian [[Awa]] models. For more info see [[LK-selectable Brand Names]].
== LK4 - Screen Refresh Rate ==