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[WP 34S] Enhanced Y register display: fractions, bugfixes etc.
02-21-2014, 07:43 AM (This post was last modified: 02-21-2014 07:46 AM by Marcus von Cube.)
Post: #38
RE: [WP 34S] Enhanced Y register display: fractions, bugfixes etc.
(02-18-2014 02:40 AM)Bit Wrote:  That's basically a trade-off between firmware size and battery life.

The increase in firmware size can be easily calculated: currently about 168 bytes with all of the optimizations enabled. I cannot guess how much the battery life would decrease if we increased the speed and kept the smaller but less efficient code. Can you comment on that?

I vote for code optimization over clock speed increase. I have no idea how bad battery life would be affected by increasing the clock frequency. It's still worthwhile to think about the latter if the device gets to sluggy despite all code improvements.

(02-18-2014 02:40 AM)Bit Wrote:  In the meantime I've been working on two things:
1. I've increased the responsiveness a tiny bit more by eliminating some more unnecessary screen updates, specifically when invoking functions. This doesn't produce such a dramatic improvement as we've seen previously but it's worth the effort because once my other optimizations are in place, it barely increases the size of the firmware further.
2. I've folded the niladic(), monadic() etc. functions in xeq.c together, moving their functionality into a universal dispatch function. This reduces firmware size by over 256 bytes, which is not a lot but it helps offset a part of the increase in size that my other changes cause.

Ad 1: You'll need to test if all temporary displays and PSE still work as expected. The whole display update stuff is quite a mess, in parts introduced by me. Sad

Ad 2: Don't forget to update the post processing code which is used during the build to replace 32 bit code addresses by 16 bit tokens. All function tables exist in two variants: The condensed version which goes to flash and the source version which is read by the post processor to update the condensed tables.

Do you think your Y display code can be modified so that it is user selectable instead of a compile time option? We'll need to find a bit to store this. We could use flag Y or add another MODE option, maybe sacrificing some other arcane setting.

Marcus von Cube
Wehrheim, Germany
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RE: [WP 34S] Enhanced Y register display: fractions, bugfixes etc. - Marcus von Cube - 02-21-2014 07:43 AM

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