Editing Apple II (section)

== Hardware Overview ==
{| class="wikitable" style="width:65%; text-align:center;"
! Sub‑system !! Specification
|-
| CPU || MOS 6502 @ 1.023 MHz (NTSC colour‑subcarrier ÷14)<ref>{{Cite web|url=https://www.oldcomputers.net/appleii.html|title=Apple II (original) - Old Computers|access-date=2024-06-20}}</ref>
|-
| On‑board RAM || 4 KB base (16 × 6116 SRAMs)<br />Sockets for 48 KB using eight 4 KB dynamic RAM banks†<ref>{{Cite web|url=https://www.oldcomputers.net/appleii.html|title=Apple II (original) - Old Computers|access-date=2024-06-20}}</ref>
|-
| ROM || 12 KB (Monitor + Integer BASIC + character generator)
|-
| Graphics || • Text 40 × 24, mixed text/lo‑res line<br />• Low‑res 40 × 48, 16 colors<br />• Hi‑res 280 × 192, 6 colors (+ artifact palette)<ref>{{Cite web|url=https://www.britannica.com/technology/Apple-II|title=Apple II | Encyclopedia Britannica|access-date=2024-06-20}}</ref>
|-
| Expansion || Eight 50‑pin slot connectors (Slots 0‑7)<br />Disk II, serial, 80‑column, language card, etc.
|-
| I/O || • Cassette in/out (mini‑jack) 1200 baud<br />• RF modulator or composite video out<br />• Game port (paddles/joystick)<br />• Speaker toggle ($C030)
|}

† Later “language cards” piggy‑backed in Slot 0 to add 16 KB bank‑switch RAM, giving '''64 KB total''' under DOS 3.3 or Apple Pascal.

=== Motherboard Revisions ===
* '''Rev 0 & 1 (1977):''' 4‑layer PCB, raised power rails; sold through serial ≈ 15,000.  
* '''Rev 4 (1978):''' Cleaner DRAM timing, support for '''Integer/Applesoft BASIC ROM switch'''.  
* '''Rev 7 (1979):''' Last original‑run board — silkscreen “Apple Computer © 1978”.