bradgrantham-apple2e/notes

per-scanline modes
    Actual Apple II TEXT/GR and HGR video address patterns are in Understanding the Apple II
        Not for DHGR or 80-col but they're probably just same address twice alternating banks
    tracking clock and reporting video memory contents
        clock
            one tick of ~1MHz clock maps to one tick of address counter
                so is 7 HGR bits or one GR/TEXT horizontal cell
                "most 6502 cycles are 978 nS long [14 14mhz clocks], but every 65th cycle is 1117 nS long [16 14mhz clocks]."
            source clock is 14.31818MHz
                unsigned long would overflow after 20 minutes
                    Could modulo byteclock by 14318180 at iterate() and not overflow
                    as long as it doesn't take longer than 20 minutes between calls to APPLE2Einterface::iterate than 20 minutes...)
                Could have clk be in 14MHz ticks.
                    unsigned long long will last 40853 years (could be slow on embedded systems)
                    Keep track of phase at clk delta time, and add 14 usually but 16 every 65th
                    Then wall clock is just always ticks / 14318180.0
                    phase_hpe initially 0
                    add_cpu_cycles(elapsed_cpu) {
                        clock_cpu += elapsed_cpu
                        clock_14mhz = elapsed_cpu * 14 + (elapsed_cpu + phase_hpe) / 65 * 16
                        phase_hpe = (phase_hpe + elapsed_cpu) % 65
                    }
            clock_14mhz is 14mhz ticks
            clock_cpu is CPU clocks, averaging 1.023MHz
            phase_hpe is clock_cpu within horizontal line
            Current CPU clk (in 1MHz CPU cycles) is used for
                which audio sample (at libAO sample rate) in the audio waveform we should fill
                    OK - should work with higher fixed rate
                mark after how many cycles the open apple key should be raised
                    OK - should work with higher fixed rate
                mark paddle timer
                    OK - should work with higher fixed rate
                incrementing CPU instruction cycles
                    OK - call add_cpu_cycles()
        address generator
            every line is 65 bytes, there are 262 lines, so there are 17030 bytes per field
            honor softswitches
            convert clock_cpu to address
            blanking and offscreen addressing during HIRES MIXED
                160 through 191 and 224 through 261
                TEXT addressing at 160, HPE' + 1 through at 192, HPE'
                argh
        read empty memory address on bus no longer fails but instead
            generate address, get byte from RAM and return it
    recording softswitch mode changes
        store vector of switch or mode change and byteclock
        instead of setting before APPLE2Einterface::iterate, pass into iterate
    honoring softswitch change in APPLE2Einterface
        initialize scanline mode array to text
        receive vector of tuple of byteclock and modes
        fill scanline mode array from passed in vector
        draw framebuffer by scanline

final release:
    help screen
    gamepad calibration screen (for desktop GLFW anyway)
        need to handle asynchronous gamepad arrival (a la HTML5)
    screenshots for README.md
    link to emscripten version

emscripten:
    safari misses 'V' for some reason
    why is it running slow in Chrome?
        runs fast in Safari and Firefox.  :-/
    upgrade to 1.37, see if -O2 issue is fixed
    audio
    paste somehow
        store paste event contents into a variable, copy that in GLFW clipboard routines?
    floppies
        IDBFS, local storage initialized from DOS 3.3 floppy and other floppies
        copy into IDBFS from other web pages
        drag and drop from IDBFS into floppy icons
    make rasterization less ugly
        retina canvas?
        limit to integer-zoomed pixels?
    GLFW - gamepad using HTML5 gamepad interface
        note that it doesn't show up until initially used

cleanup:
    deglobalize where possible
    lower and underscores throughout
    exceptions?
    tableize 6502?

Run this software, purge fake6502:
    ProDOS
    LodeRunner
    ChopLifter
    Digitizer
    Plasmania
    Christmas Carols
    Data Capture //e
    Contiki no network
    Idiom Translator
    Pascal - Brad's Disk
    ...?

apple2e -diskII diskII.c600.c67f.bin ~/Downloads/LodeRunner.dsk none apple2e.rom < /dev/null

Actual ROM files that are in our Apple IIe, and run Brad's sound digitizer:
    wget http://www.applelogic.org/files/3420135A.BIN
    wget http://www.applelogic.org/files/3420134A.bin
    cat 3420135A.BIN 3420134A.bin > apple2e_a.rom
    (dd if=/dev/zero bs=16384 count=1 ; cat 3420135A.BIN 3420134A.bin) > apple2e_a.rom
    apple2e -diskII diskII.c600.c67f.bin ~/packages/Disk\ Images/Brad\'s\ Handwriting/Sound\ Digitizer\ Original\ 1.2.dsk none apple2e_a.rom