M7264 Troubleshooting

[Noel Chiappa]

    > From: Allison

    > ODT for the two systems are very different. .. KDF-11 the ODT is part
    > of the higher level code. The larger cards (11/23 and 23+) boot to
    > resident (ep)rom.

Ah, no. (Well, the KDF11 CPU's can boot to EPROM, which in the -11/23+ can be
on the CPU card; the -11/23 is a dual card and has no functionality on the CPU
card except the CPU.)

The ODT in the KDF11's (and KDJ11's) is, just like in the LSI-11's,
microcode, not macro-code. From the 1982 'microcomputers and memories'
handbook, pg. 161 (in Chapter 7, "Octal Debugging Technique (Microcode
ODT)"):

  "The console emulator Octal Debugging Technique (ODT)is a portion of
  the processor microcode ... The console ODT implemented on the LSI-11/23,
  PDP-11/23 and PDP-11/23-PLUS is identical."

and on pg. 154:

  "Unlike the LSI-11 and LSI-11/2, the LSI-11/23 does not enter console
  ODT upon occurrence of a double bus error"

>From which I think is quite clear that the KDF11's have microcode ODT.

      Noel