apple2idiot/notes.md

Needed changes to board

DONE: Add a GND and +5V breakout. Fix DEVSEL address in silkscreen docs. DONE: Unconnect addresses above A7. DONE: Add diode to +5V.

Ordered:

• 5PCS IDT7132SA100P IDT7132SA DIP-48 HIGH-SPEED 2K x 8 DUAL-PORT STATIC RAM
• STM32F411 "BlackPill" Development Board

Misc

• https://pastebin.com/raw/1kR0vbRA

ESP32 Interupt Issues

• ESP32 Thread I started: https://esp32.com/viewtopic.php?f=12&t=21855
  • " Consider 74ls373 to latch the value to be processed by software."
  • It might also be worth trying ESP32's assembly high-level interrupts. I've never used them personally, but they can allegedly give interrupt latencies that are significantly lower than the ~2us for regular ESP32 C interrupts.
    • See: https://esp32.com/viewtopic.php?t=422
    • See: https://docs.espressif.com/projects/esp ... rupts.html
  • components/esp_system/port/soc/esp32/dport_panic_highint_hdl.S

Python binar/hex/dec manipulation

In [11]: format(10, '016b')
Out[11]: '0000000000001010'

bin(10)

Jumper and Breakout pins

• Input (to ESP32) only ~IOSEL (from Apple2) ~BSYL (from Apple2 side of IDT7132) ~BSYR (from ESP32 side of IDT7132)

• Apple II Pins to header
  • IOSEL
  • DEVSEL
  • IOSTROBE
• IDT7132S Pins to header
  • BSYL
  • BSYR
• ESP32 Pins to header
  • GPIO 0
  • GPIO 1 (TX)
  • GPIO 2
  • GPIO 3 (RX)
  • GPIO 4
  • GPIO 26
  • GPIO 27
  • GPIO 32
  • GPIO 33
  • GPIO 34 (input only) No pullup, needs resistor?
  • GPIO 35 (input only) No pullup, needs resistor?
  • SENSOR_VP (input only) No pullup, needs resistor?
  • SENSOR_VN (input only) No pullup, needs resistor?