Fragile release 2.6.3.222

[C Burch]

The newest fragile release includes the repaired Portuguese
translation, and it addresses several additional bugs. I've worried
too about the issue Ilia mentioned, where older projects were built
with multiplexers/demultiplexers have wires going across where now the
enable input is located. Ilia proposed a nice approach to this, but I
opted for a simpler-to-implement alternative:
Multiplexers/demultiplexers have an additional attribute configuring
whether an enable input should be present. When you load files created
with older versions, this attribute defaults to "no," but it defaults
to "yes" for newer files.

Feature: Added 250%, 300%, 400% to the options for zooming.

Bug fix: The "Set As Expression" button would sometimes not be
disabled when pressed (particularly when the previous expression was
the same except for spaces).

Bug fix: The "Second radix when wire poked" preference was ignored -
the "First radix" was displayed twice when the wire was poked.

Bug fix: Some instances of exceptions that would occur upon doing
"Analyze Circuit" a second time were removed.

(Feature: Added "Include Enable?" attribute for multiplexer,
demultiplexer, and decoder.)

(Bug fix: Tool halo would not disappear when switching to Poke Tool.)

(Bug fix: If not viewing selection attributes, changing the selection
should switch to viewing the selection attributes.)

-Carl

[Ilia Lilov]

Carl, there was confusion with labels of outputs "sum" and "carry" in
HA and FA circuits of verify.circ; I fixed them. Screenshot
verify-adder-query.png shows FA emits two error values, but it has to
emit error only for "sum" output. If we have that artificial mistake
with not connected carry between HA and FA, "carry" output of FA will
emit "0" regardless you will implement it as sum of products or
product of sums. May be I'm missing something and you're going to show
another one artificial mistake?
I'm sorry for annoying, but there is no note about new items in pop-up
menu for splitters in the documentation yet.

"Set as expression" button of Combinational analysis module still
behaves strange. One of the ways to reproduce: in the Minimization
tab, change "Sum of products" to "Product of sums" for any output. The
button will be inactive (grey) because product of sums will be set as
expression automatically, and it's OK. Now go to Expression tab and
then come back to Minimization tab: "Set as expression" button will be
active again, but it shouldn't be.

Ilia.

[C Burch]

Thanks, but if I understand what you're saying is wrong with the
screenshot, I believe you're incorrect. Given the input values
illustrated in the screenshot, the inputs to the full adder are 0, 1,
and Z (the "carry" input that is unconnected). The full adder's
"carry" output could be 0 or 1 depending on the "carry" input, so a
"carry" output of X is appropriate.

In the screenshot used for previous versions, the full adder's inputs
were 0, 0, and Z. In that case, the "carry" output would be 0
regardless of the "carry" input, so the earlier screenshot showed 0
for the full adder's "carry" output.

(I'm not sure why I switched the values between the previous version
to this one - though I do think it helps visualize the wires if
they're not all dark green.)

All that said, there is an error in that screenshot: The half adder
output's are reversed, and I'll repair that.

-Carl

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[Ilia Lilov]

Carl, I think it worth to release the last fragile before stable
release and to give little time for translators to check strings, as
well as to give us a chance to catch last bugs (if any). I think
stable version release is too rare event to hurry. :)

Ilia.

[C Burch]

Thanks, but it's time to get the new version out there. About a week
ago, I warned that the new version would go out on March 4. I waited
over the weekend, but it's now time. On Wednesday, I'm going to a
major conference on computer science education (SIGCSE) where I'll be
discussing changes to Logisim, and I want this version out there for
that. Moreover, I won't be able to work on Logisim much while I'm
there: If I don't get it out today, it'll be another week before this
gets released.

The changes for translation since the last fragile release have been
only a few relatively minor documentation edits. If a translation
corresponds to the documentation used in the last fragile release,
it's not really that big of a deal.

If there are additional bugs caught, then I'll address them upon my
return. I'm reasonably confident that this version is in good shape.
It certainly repairs several bugs from the previous stable release, so
it's conceivable that it's in better shape than before.

-Carl