From: ohland@charter.net   
      
   Long, convoluted story SNIPped.   
      
   Katherine Rohl was probing her 8580-Axe, and I brought up the "fact"   
   that the Corvette would not configure on an 8580.   
      
   While I was listing the RTC/SRAM/NVRAM configurations for all PS/2s, I   
   noticed that the -Axx system board uses >8KB NVRAM<... but according to   
   myth-legend, the Corvette needs 8K NVRAM... Huh, Way To the Future?   
      
   Unlike me, Katherine fired up some painful probulation interrogation   
   devices, attached them to very sensitive portions of her 8580, and   
   extracted unknown information...   
      
   The Corvette lacks a SCSI BIOS. It needs either another SCSI controller   
   with a SCSI BIOS, -OR- an IML BIOS with the SCSI BIOS baked in.   
      
   Katherine Rohl on the Corvette in an 8580: --------------//   
      
   Also, the problem with the Corvette adapter in the Model 80 was obvious   
   now that I've realized it: There's no SCSI BIOS. It presumably goes in   
   the empty PLCC socket. The mapping in SC is just for its *address   
   space.* I guess it's expecting to be run in an IML system which provides   
   a SCSI BIOS to place in that address space.   
      
   I don't have any IML systems, though - I'm going to experiment with   
   modifying the Corvette ADP to *not* unload Spock's SCSI BIOS and see if   
   that does anything.   
      
   My thinking is that you could probably come up with a SCSI BIOS pretty   
   easily for the Corvette. Since it’s in the same family as Spock (the ADP   
   is nearly identical as well, I need to document the differences) I bet   
   it was another one of those IBM “if you want SCSI-2, buy a 90 or better”   
   bonehead decisions to protect server sales.   
      
   The ADP (all of them, Tribble/Spock too) defers to IML if the system’s   
   BIOS feature bits declare that it is an IML system with SCSI BIOS   
   present. Since that’s not the case in a Model 80, it falls back to   
   expecting the BIOS to be on the adapter and declaring its upper memory   
   range. But there’s no device present so it just returns an open bus.   
   Declaring a memory range and running the option ROM are two unconnected   
   steps in the boot sequence - POST searches for option ROMs like a PC,   
   not at a table of declared POS memory ranges.   
      
   The easiest thing would be if you have a Corvette card in something that   
   does work with it, identify and dump the IML SCSI BIOS range in upper   
   memory and compare it to the known 1991 SCSI BIOS.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)