|Latest DIY calculator news|
Message #1 Posted by Eric Smith on 22 Sept 2012, 10:45 p.m.
I just gave my presentation at HHC 2012. The news is that the DIY4X now runs a modified version of Thomas Okken's "Free42" software.
The LCD display has eight character rows, rather than two in the original HP-42S and in Free42. I reserve the bottom row for soft menus, so that everything else doesn't move up and down when the menus are activated and deactivated. In run mode, all four levels of the stack are displayed, and any error messages are shown at the top.
In program mode, seven program lines are displayed, and the scrolling is done such that whenever possible, at least two lines before and after the current line are displayed.
The DPLOT program from the 42S user manual works with only two lines changed to take into account the larger display.
The display hardware is capable of 400x240 pixel resolution. It is strictly black and white, though grey can be obtained by dithering. The Free42 code was written based on a 131-pixel wide display, so currently the pixels are scaled by a factor of 3 on both horizontal and vertical axes. Later I hope to make Free42 work at native resolution, which will look much smoother.
A subset of the HP-IL Mass Storage functions are implemented, allowing saving programs to and loading programs from a MicroSD card.
There is USB support in the bootloader, allowing firmware upgrades from either the MicroSD card or a host computer via USB. The calculator does not currently have USB support, though I plan to add it, making it look to the PC like a communications devices. The calculator will use HP-IL control functions such as OUTA to talk to the PC.
We didn't get the DIY5 hardware completed in time for the conference. It will have the 42S keyboard layout and the form factor will be similar to the 20b/30b.