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Merge pull request #33 from 0cjs/dev/cjs/21m07/jumper 

Jumper description fixes
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tebl 2021-12-07 14:30:39 +01:00 committed by GitHub
parent e395f2787f 6b8fa61b8c
commit a8658fbd96
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12
RC6502 Apple 1 SBC/README.md
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@ -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