not sure this went out 11/45 status

Guy Sotomayor ggs at
Tue Mar 1 10:50:41 CST 2005

On Tue, 2005-03-01 at 10:26 -0600, Jay West wrote:

> 1) In the absence of full docs on the MF11-L... I'm not sure about the
> following. It looks like the 1st slot of the MF11-L backplan gets a unibus
> in (A-B) from the last slot of the cpu backplane. The 2nd slot is my G110,
> the 3rd is my G231, and the 4th slot has my H214 (C-F) in it. But looking at
> some of the docs, it appears that an H214 can be in slots 1, 4, and a few
> others per the diagram. My system arrived with one H214 in slot 4. Should it
> be first... in slot 1 under the unibus in? Since I had a spare from ashley,
> I put one in slot 1 and one in slot 4. I know the jumpers on the other
> boards may not reflect 16K, but I figured it might change things. So if I
> have just 8K set up, should the H214 be in slot 1, 4, or does it matter?

I *think* I have full docs for it.  Let me look it up in the next couple
of days and I'll get back to you.  I should at least have a module
utilization for an MF11-L.
> 2) My front panel has an oddity (to me). If I select say address 10000 and
> hit load addr the address lights respond correctly with 10000. I then hit
> examine and get nothing (blank data lights). Whatever... but here's the
> interesting part. If I keep pressing examine over and over again, the
> address lights count up just like they should - except they skip bit zero
> (the rightmost bit, either 0 or 15 whatever dec nomenclature is). I don't
> mean that the rightmost bit just isn't displaying correctly, the actual
> counting sequence acts like the rightmost bit is the 2nd light from the
> right. I can tell it's not just a bulb problem because I don't have to hit
> load addr twice to "move on", the count is smooth and sequential without the
> rightmost bit. Any thoughts offhand?

That is correct behavior.  The 11's are 16 bit machines but are capable
of byte addressing.  When they're doing words, bit 0 is well 0.  When
they're doing bytes, bit 0 can be either to represent the correct byte.
Front panel operations are done as words, hence bit 0 will be 0.


TTFN - Guy

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