Solbourne Graphics Board Specifications:
(data from a Solbourne Education manual, unless otherwise marked)

Board        VideoMode   Frequency (H/V)     Requirements
-----        ---------   ---------           ------------
[* KBus Boards *]
I/O Mono     1152x900    /69Hz
             1600x1280   89KHz(**)/66Hz      a high-res mono monitor!
CG30         1152x900    /69Hz               Needs 3.2B or greater ROM
CG40         ??          /??
             1152x900    /69Hz(**)

[* SBus Boards *]
sga20        1152x900    /69Hz
             1152x900    61.9KHz(*)/65Hz(*)
bw20         1152x900    /69Hz
             1600x1280   89KHz(**)/66Hz      a high-res mono monitor!

(*) as obtained from the information report from an HP A4330A monitor
    this doesn't seem right to me, as the sun video is 61.8KHz/66Hz,
    which doesn't seem far enough off to cause the HSync problems you
    see.  Maybe i'll explore this at a later date)
(**) assumed from other information