($1298) up to 48K ($2638) 1979: Apple ][+ 48K RAM standard (additional bank-switched 16K available) Applesoft BASIC from Microsoft 1983: Apple / /e 64K RAM standard lowercase letters!
ROM booting but Integer BASIC didn’t work February 2007: Google Code massive refactor of 6502 code August 2011: Github patches within hours from Greg Hewgill completed 6502 support, low and high res graphics, sound, cassette and more ApplePy
and 3 special-purpose registers accumulator register (A) 2 index registers (X, Y) status register (P) stack pointer (S) program counter (PC) about 60 commands
row_group, column = divmod(lo, 0x28) row = hi + 8 * row_group mode, ch = divmod(value, 0x40) There and Back Again BASCALC PHA LSR A AND #$03 ORA #$04 STA BASH PLA AND #$18 BCC BSCLC2 ADC #$7F BSCLC2 STA BASL ASL ASL ORA BASL STA BASL RTS
cycle count everywhere when speaker is toggled we note the cycle and append to a sound wave array everyone once in a while, we play the sound wave array
wave when softswitch is read, convert cycle number to how far into the sound wave we are keep track of whether we’ve crossed zero since last time so far works about 10% of the time
bytes 7 bits are the pixels high-bit is the palette odd/even bits are different colors palette 1: black, green, magenta, white palette 2: black, blue, orange, white