diff --git a/RC6502 Apple 1 SBC/README.md b/RC6502 Apple 1 SBC/README.md index 4892de8..2b3396f 100644 --- a/RC6502 Apple 1 SBC/README.md +++ b/RC6502 Apple 1 SBC/README.md @@ -88,20 +88,18 @@ box around the pins that enable. the expansion bus connector. - `VP GND` - - Shorted: WD65C02 CPU. Leaves pin 1 of the CPU (`V̅P̅` on the - WD65C02) floating. - - Open: Original MOS 6502, UM6502, SY6502, R65C02. Connects pin 1 of - the CPU to ground, providing an additional ground connection for - the CPU. + - Shorted: Original MOS 6502, UM6502, SY6502, R65C02. Connects pin 1 of the + CPU to ground, providing an additional ground connection for the CPU. + - Open: WD65C02 CPU. Leaves pin 1 of the CPU (`V̅P̅` on the WD65C02) floating. - `PIA_EN` - Top pair shorted: Enable PIA. Connects `CS1` to Vcc. - Bottom pair shorted: Disable PIA. Connects `CS1` to ground. - `RAM_EN` - - Left pair shorted: Enable RAM. Connects RAM `C̅S̅`/`O̅E̅` to address + - Left or upper pair shorted: Enable RAM. Connects RAM `C̅S̅`/`O̅E̅` to address decoding logic (`CS_RAM`). - - Right pair shorted: Disable RAM. Connects RAM `C̅S̅`/`O̅E̅` to Vcc. + - Right or lower pair shorted: Disable RAM. Connects RAM `C̅S̅`/`O̅E̅` to Vcc. - `ROM_EN` - Top pair shorted: Enable ROM. Connects ROM `C̅E̅`/`O̅E̅` to address