Re: SBus driver & burst (>32 bits) accesses

[Chase Rayfield <cusbrar2%yahoo.com@localhost>]

Also at least the 32bit sun4m SS20 and probably hyperstation 30 support 64bit sbus extensions,  with up to 128byte burst... in hardware. It may have never been implemented in Solaris but Sunflash vol 65 #75 indicates the hardware supports the requisite extensions and was slated to be supported sometime in a Solaris 2.x release.

Basically Microsparc is 16byte burst (potentially reprogrammable to longer bursts), microsparc II 32byte, Sparcserver sun4d machines can do 64byte bursts. And the SS20 and potentially clones or later machines like ultrasparcs of course can do 128byte bursts since they have 64bit sbus in hardware.

There are a couple 64bit sbus cards in existence dunno which ones would acutally work in an SS20... its possible nobody ever bothered. The gigabit ethernet sbus card should be one that would work.

There are several FAQs floating around the net with this info. http://ftp.lanet.lv/ftp/sun-info/sunflash/1994/May/SunFlash:-65.75-SPARCstation-20
and
http://www.alyon.org/InfosTechniques/informatique/SunHardwareReference/sunfaq.html


Accidentally sent this only to Eduardo, anyway resending to the list now!

Chase Rayfield