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[WP 34S] Enhanced Y register display: fractions, bugfixes etc.
02-11-2014, 07:59 PM
Post: #27
RE: [WP 34S] Enhanced Y register display: fractions, bugfixes etc.
(02-11-2014 03:35 AM)Bit Wrote:  2. In order to find out how many digits can be displayed in the dot matrix display and whether to switch to exponent notation, a simple iteration is performed in annunciators(). This is not much of a problem for the original WP 34S as it displays a second number only after complex operations, but with Y register display a more efficient solution is worth the effort. A near constant time algorithm could probably be devised but it'd further increase the size of the firmware. Therefore I only added some simple logic to decrease the number of iterations. My rough estimate is that the typical number of iterations has been reduced by 50% and the worst case by 60%.

I did think about trying to do this faster but so much depends on display modes and the widths of the characters themselves. 11111 takes less pixels than 88888 e.g. The brute force solution seemed easiest and it is very small. A binary search approach might work better, still cover the entire range and require fewer iterations -- start at the mid-point and ask does this fit? If not halve the digit count, if so double it and try again.

Quote:3. The original WP 34S updates the entire screen every time a key is pressed and then again every time a key is released. This is too slow with Y register display enabled.

The press and hold to display the function which then nulls out might confound things here.

- Pauli
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RE: [WP 34S] Enhanced Y register display: fractions, bugfixes etc. - Paul Dale - 02-11-2014 07:59 PM

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