DEC 3000 (alpha) faultfinding

[Maciej W. Rozycki]

Hi Peter,

> J8 (position 0) is where the jumper already is on both my 3000 600 machines.
> It is possible that this is where it normally is, however, it is also possible
> that I moved it there some time ago in an attempt to diagnose the problem and
> I have since forgotten.  Which position is the jumper at in your system?

 It's in at position 0 (J8), as per documentation.

> Anyway, you spurred me on to try moving it to some of the other positions.
> When I place it at J3 (position 5), I get this:
> 
> DEC 3000 - M600 SROM 6.1
> Mfg Test
> ff.fd.fb.f0.
> MCRstat 11111111.808011c0
> bnkSize 00000300.00000c01
> memSize 000000c0.000000c0
> 
>         memTest (no-cache)
>         LongWord Memory Test
> 
> ....done.
> ....done.
> ....done.
> 
> The last line repeats approximately every minute or so, possibly indefinately.
> 
> However, when I place the jumper at J2 (position 6), I get this:
> 
> DEC 3000 - M600 SROM 6.1
> Mfg Test
> ff.fd.fb.f0.
> MCRstat 11111111.808011c0
> bnkSize 00000300.00000c01
> memSize 000000c0.000000c0
> 
>         memTestCacheOn
>         LongWord Memory Test
> 
> address:0bf7dad8 wrote:ffffffff read:ffffddee
> address:0bf7da58 wrote:ffffffff read:ffffddee
> address:0bf7d8d8 wrote:ffffffff read:ffffddee
> address:0bf7d858 wrote:ffffffff read:ffffddee
> address:0bf7d2d8 wrote:ffffffff read:ffffddee
> address:0bf7d258 wrote:ffffffff read:ffffddee
> address:0bf7d0d8 wrote:ffffffff read:ffffddee
> 
> ... followed by many many similar lines.  It looks like I have cache problems.

 These must be the alternative diagnostic routines mentioned the system 
programmer's manual:

"A DECchip 21064-AA CPU, including on-chip 8-KB instruction and 8-KB data 
caches, and a 64-KB serial boot ROM.  A 64-KB stream holds the primitive 
boot code for booting the operating system.  Jumpers provide for the 
selection of up to seven other streams for diagnostic and other purposes. 
(The entire UVPROM is 64 K x 8.)"

> Thanks but in light of my cache problems, it looks like I need to deal with
> those first.  Perhaps the SYSROM is getting copied into main memory but when
> the in-memory copy is read for execution, garbage is returned due to the cache
> errors, leading to the system hanging with F0 on the diagnostic LEDs?  However,
> according to one of the manuals (but not the other!), cache errors should have
> been detected before the LEDs counted down as far as F0.

 I take it F0 is the last output from SROM before handing control over to 
SRM.  Now that you've got a way to see SROM diagnostic output directly I 
would expect these codes not to matter as much anymore.

  Maciej