I did not find much info for the RetinaZ3, just a few hints from the kernel-documentation. You definetely have to use video=retz3 for the rest, experiment a little... 5.1) video= ----------- Syntax: video=: The parameter specifies the name of the frame buffer, valid options are mifb', yber', 'virge', etz3' and lgen', provided that the respective frame buffer devices have been compiled into the kernel (or compiled as loadable modules). The behavior of the option was changed in 2.1.57 so it is now recommended to specify this option. The is a comma-separated list of the sub-options listed below. This option is organized similar to the Atari version of the "video"-option (4.1), but knows fewer sub-options. 5.1.2) depth ------------ Syntax: depth: Specify the number of bit-planes for the selected video-mode. 5.1.5) monitorcap: ------------------- Syntax: monitorcap:;;; This describes the capabilities of a multisync monitor. For now, only the color frame buffer uses the settings of "monitorcap:". and are the minimum and maximum, resp., vertical frequencies your monitor can work with, in Hz. and are the same for the horizontal frequency, in kHz. The defaults are 50;90;15;38 (Generic Amiga multisync monitor).