Member readme.3rd of archive ps2scsi.tgz:

This readme is only for those who upgraded 386 to Cyrix
Cx486DRx2.

To improve performance, I enable cyrix to cache anywhere except
the 640k-1M region. Also, I enable pipelining, which gives 5-10%
more performance. With Cx486DRx2 running at 50/25Mhz in my PS/2 model
70, I get 19.97 bogomips with the fix below.

Insert the code below into file linux/arch/i386/setup.S. The
exact location of insertion probably does not matter, I do it
just above comment `! Get hd1 data' in that file.

! Setup For Cyrix processor:

  mov al,#0xc0            ! write 0x12 into CCR0
  out #0x22,al
  mov al,#0x12
  out #0x23,al

  mov al,#0xc1            ! write 0x0 into CCR1
  out #0x22,al
  mov al,#0x00
  out #0x23,al

  mov al,#0xc3            ! write 0x8 into CCR3
  out #0x22,al
  mov al,#0x8
  out #0x23,al

  mov al,#0xc4            ! write 0x000000 into NCR1
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xc5
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xc6
  out #0x22,al
  mov al,#0x00
  out #0x23,al

  mov al,#0xc7            ! write 0x000000 into NCR2
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xc8
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xc9
  out #0x22,al
  mov al,#0x00
  out #0x23,al

  mov al,#0xca            ! write 0x000000 into NCR3
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xcb
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xcc
  out #0x22,al
  mov al,#0x00
  out #0x23,al

  mov al,#0xcd            ! write 0x000000 into NCR4
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xce
  out #0x22,al
  mov al,#0x00
  out #0x23,al
  mov al,#0xcf
  out #0x22,al
  mov al,#0x00
  out #0x23,al