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Q1 Front Panel

The front panel allows one to control the clock and access the memory of the Q1. The layout is as follows.

+-------------------------------------------+
| A A A A  A A A A  A A A A  A A A A  IA RN |
| m m m m  m m m m  m m m m  m m m m        |
|                                           |
| RS ST             D D D D  D D D D  DP ID |
|                   m m m m  m m m m        |
+-------------------------------------------+

• A represents an LED for the address bus. The left-most LED displays the most significant bit. Directly below the address LEDs is a push button to toggle the address bit in the address input buffer.
• IA is a toggle switch to select between the CPU address bus and the input address buffer. When in the up position the address input buffer is displayed and the address input buffer is used for the RAM address. In the down position the address from the CPU is displayed and used for the RAM address.
• D represents an LED for the data bus. The left-most LED displays the most significant bit. Directly below the data LEDs is a push button to toggle the data bit in the data input buffer.
• ID is a toggle switch to select between the data bus and the data input buffer. In the up position the data input buffer is displayed and asserted on the RAM data bus. In the down position the data bus is displayed.
• RN is a toggle switch to switch between RUN and HALT. When in the RUN (up) position the CPU is run from the clock generator. In the HALT (down) position the CPU may be stepped via the ST button and the memory can be modified. Note that this switch should always be in the HALT position before switching IA or ID up or pressing DP.
• DP is a push button to deposit the data in the data input buffer at the address shown on the address LEDs.
• RS is a push button to reset the state machine and program counter.
• ST is a push button to step the clock (to be used when halted). This will step through one complete clock phase.

Running a Program

1. Set the RN switch to "HALT" (down).
2. Set the IA switch to "Input" (up).
3. Set the ID switch to "Input" (up).
4. Set the address and data.
5. Press DP.
6. Repeat 4 and 5 until the program is loaded.
7. Set the IA switch to "View" (down).
8. Set the ID switch to "View" (down).
9. Press RS.
10. Place the RN switch into the "RUN" (up) position.