bradgrantham-apple2e/notes
2018-07-30 16:01:39 -07:00

101 lines
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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
honor softswitches
convert clock_cpu to address
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