According to both Linux and NetBSD, port B bit 6 is used on the Quadra 800 to
configure the GLUE logic in A/UX mode. Whilst the name VIA1B_vMystery isn't
particularly descriptive, the patch leaves this to ensure that the constants
in mac_via.c remain in sync with Linux's mac_via.h.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <
20211020134131.4392-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
* On SE/30, vertical sync interrupt enable.
* 0=enabled. This vSync interrupt shows up
* as a slot $E interrupt.
+ * On Quadra 800 this bit toggles A/UX mode which
+ * configures the glue logic to deliver some IRQs
+ * at different levels compared to a classic
+ * Mac.
*/
#define VIA1B_vADBS2 0x20 /* ADB state input bit 1 (unused on IIfx) */
#define VIA1B_vADBS1 0x10 /* ADB state input bit 0 (unused on IIfx) */