The Computer Engineer Quick-Test

The Computer Engineer Quick-Test (Version 0.06):

  1. Define software. Define firmware.
  2. Sort these characters by their ASCII ranking:
    0 (numeral zero)
    5 (numeral five)
    (space)
    A (Uppercase A)
    a (lower case A)
    ^a (control-A)
    @ (at-sign)
    ! (exclamation point)
    ^[ (escape)
  3. Which does not belong?
    256t
    0x100
    0400
    0ffh
    100000000b
  4. When connecting a resistor, which lead goes to the more positive node?
  5. True or false? Unused TTL inputs are better left unconnected.
  6. Define: Voltmeter, Ammeter, Potentiometer
  7. ASSERT- is a negative-logic TTL signal. When ASSERT- was measured, it was measured at 0.2v. Was ASSERT (instead of ASSERT-) logically true or false?
  8. VRAM, DRAM, and SRAM are all interchangeable. They're named differently merely for marketing reasons. True or False?
  9. Engineer Joe can tell if his processor has halted by glancing at the mA display on his power-supply. How does he do this?
  10. What does "locating code" mean? Why can't you just burn object files directly onto the ROM?
  11. What is indirect addressing? If your processor does not explicitly support indirect addressing, how could you achieve a similar functionality? (You can assume that your processor does not have separate execution and data memory spaces.)
  12. True or False? CISC code is typically longer than its RISC counterpart.
  13. Your C-compiler includes printf as a part of its standard library; however, whenever you use printf, the linker complains: "_putc: undefined symbol". Give a possible explanation and how you might go about fixing this problem.
  14. For power-supply decoupling on your digital system circuit board, which would be the better choice? Why? (Assume that cost and physical size are non-issues.)
    a) 100 1uf capacitors + 4 100uf capacitor
    b) 5 100uf capacitors
    c) 1 500uf capacitor.
  15. A 4.7K ohm resistor is typically used for pulling up a TTL input. Why not a 4.7M ohm resistor? How about a 4.7 ohm resistor? [Bonus point for explaining why 4.7K ohm is such an attractive resistor value...]
  16. Which does not belong?
    HI-Z
    Open-collector
    High-impedance
    Tri-state
  17. "When a latch is holding its assigned value, it has latched up." What's wrong with this statement?
  18. You're wiring a multi-output power-supply to your project. Match the voltages to the "best" wire colors: Voltages Colors 0 Blue +12 Yellow +5 Black Chassis Red -12 Green [Admittedly, this is very subjective, but some color choices are clearly wrong.]
  19. A finite-state-machine has two inputs, three outputs, and eighteen defined states. Can you fit this state-machine onto a 2716? What if there were four inputs, three outputs, and fifty-six defined states? Explain. (A 2716 is a 2K-word by 8-bits/word read-only memory device.)
  20. True or false? "It is acceptable to short two open-collector outputs together. It is not acceptable to short two totem-pole outputs together."
  21. What is microcode? Is it the same as firmware?
  22. Why do SCSI chains need terminators?
  23. What is the difference between random-access memory and hard-disk memory in your standard workstation?
  24. When pin X is asserted, the processor changes its instruction-pointer (currently set at addressN in procedure FOO) to the beginning of procedure BAR. At the end of procedure BAR, the instruction-pointer changes to address N+1 in procedure FOO. Which of the following best names Pin X?
    a) Conditional Branch Pin
    b) Code Block Pin
    c) Interrupt Pin
    d) Halt Pin

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