SPARCstation 20 with SCSI2SD

[Maciej W. Rozycki]

On Sat, 1 Dec 2018, alan--- via cctalk wrote:

> I'm not sure what the 'B' in the middle means (silicon rev?), but the DS12885
> has been around for decades.  I use them the JR-IDE project.

 Yes, the DS12885 is a standard part, still in production (with a trailing 
+ marking RoHS compliance).

 According to its datasheet the DS12B887 has an NC pin actually present in 
the position where the DS12885 has the RESET# line, while the remaining NC 
positions are absent due to the respective pins having been bent up (or 
"are missing by design", as the datasheet puts it).  So either a different 
core had to be used with the DS12B887 or the datasheet has an error.

 However RESET# would have to be connected to VCC for normal operation and 
there is no mention of an internal pull-up on RESET# with the DS12885, so 
I take it the DS12B887 had to use a different core and a DS12B885 seems 
like a logical match.

 The placement of RESET# right in the middle between VBAT and GND makes it 
highly unlikely an internal discrete connection has been made in the 
DS12B887 package between RESET# and VCC, as a shortage to the embedded 
lithium cell from that pin if bent up and soldered to would be virtually 
unavoidable.

  Maciej