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Who wrote this stuff?
This trivia was originally written by Jim Brain as part of the now long defunct C= Hacking Magazine, but happily Jim has kindly agreed to let me reproduce it in HTML-ized format for retro computing fans everywhere.

If you are interested in seeing the Commodore Trivia digests in their original form, take a look at this website.

For those who are interested, these pages were generated from the original text files using Perl and Velocity (and a nice template originally found here)


	 What does the letters IEEE in IEEE-488 stand for?

	Institute of Electrical and Electronics Engineers.

	What was the logo of Batteries Included?

	It was a the face and hands of a man with glasses inside a circle.
        Early renditions of him were in black and white, while later ones had
        him with blond hair a a red shirt.  Some views had him actually 
        typing on the 64/VIC with one finger, but most just showed him, 
        not the keyboard.

	The Commodore VIC-20, 64, and 128 computers emulate in software a very
        important integrated circuit. What is its number, and why is it 

	The 6551 UART IC.  It is used for RS-232 communications.

	 Commodore watches play a beautiful song for the alarm.  What is the
         song's title?

	Fleur-de-lis.  The "Godfather" theme.

	The C2N style Commodore tape decks are impressive in handling errors.
        How many times is a single program stored onto tape?

	Twice, second copy is placed right after the first.  That means, even
        if you get a load error on load, you might be able to just run the 
        program anyway, as a load puts the first copy in memory, and verifies
        it against the second copy.

	 What is a jiffy?

	A jiffy is 1/60th of a second.  It is the same on PAL and NTSC
        Commodore computers.

	What is the screen resolution of the Commodore VIC-20?

	On the VIC-I IC, the text and graphics screens are definable within
        limits.  Therefore, there are a number of answers that are correct:
        The default screen has (and the answers I was looking for):
        Text:     22H x 23V = 506 characters
        Graphics: 176H x 184V = 32384 pixels
        However, on experimentation with a NTSC VIC-I (6560), I found that
        it could support a resolution of:
        Text:     24H x 29V = 696 characters
        Graphics: 192H x 232V = 44544 pixels
        Your mileage may vary, but these numbers remove all border area.
        (I am not sure if you can use all the pixels, since the VIC-I only
        allows 32768 to be used.  You might be able to flip the graphics
        page in the middle of the screen, but I leave that as an exercise.)
        The VIC-I also supports a virtual screen, which can be "panned" so
        that the physical screen becomes a "window" into the virtual screen.
        The maximum "scrollable" virtual screen on NTSC is:
        Text:     28H x 32V? = 896 characters
        Graphics: 224H x 256V? = 57344 pixels
        The VIC supports more resolution than 32V, but you can never see
        it since you can't scroll it into view, so the point is moot.
        So, if I didn't thoroughly confuse you, email me and I will make
        sure I do!

	Why is the VIC-20 named the VC-20 in Germany?

	Because 'V" is pronounced 'F" in Germany, and the resulting
        pronunciation was a naughty word. 
        Commodore put one over on many people.  The VIC-20 was designed in
        the states and given that name due to the IC that did the graphics.
        When the marketing started, CBM found out the name was no good in
        Germany, so they quickly renamed it VC-20.  The after-the-fact
        Volks-Computer conjured up images of the Volkswagon car (VW), which
        was popular at the time for its dependability and price.  The rest is

	 Why was early Commodore equipment built into such heavy enclosures?

	Simple.  Commodore made office furniture, which includes desks and
        filing cabinets.  They simply used the facilities and parts on hand.
        The fact that, at the time the PET came out, people equated physical
        stability of a machine as an indication of its worth, served only to
        reinforce the decision.  Also, the system had to hold up the built-in
        Most people think it is due to FCC regulations.  FCC regulations had
        not been determined at the time the PET came out, although the
        engineers did know that the CRT produced many electrical hazards which
        could be alleviated with a shielded metal case.  Commodore has always
        been a "cheap" company, so the fact that they could get good
        shielding in-house at almost no cost proevd to be the overriding
        factor. It might interest some to note that, even with the metal
        case, early PETs had foil inside as a secondary shield.  The reason
        has to do with the keyboard being mostly plastic, as the shield fit
        directly underneath, but the reason for it remains a mystery to me.

	What two BASIC 2.0 commands might still work if mispelled?

	The answers I was looking for are END and STOP, although someone
        correctly pointed out that GO TO can be construed as a mispelling.
        Also, print#, get#, and input# might work if the '#' was omitted and 
        the program was getting data to screen or keyboard.
        Although the following aren't really the result of mispelled commands,
        I put them in, since you could stretch the definition of mispelled to
        include them.
        LET would work if it was left out, since LET was an optional 
        keyword.  Commands of the form   would
        work if letters were tacked onto the end. (example: RUNDY., prg has 
        a valid line 0, and DY = 0).  Finally, LOAD"jim",8,1garbage would
        work due to the way LOAD absolute worked, but that is a stretch!

	What does CIA stand for? (not the U.S. CIA!)

	CIA = Complex Interface Adapter.  The german Magazine 64'er calls
        it a Control Interface Adapter, but that is not its official

	(hard one) What is the key VIC capability that makes full-screen
        hires graphics possible on the _VIC-20_?

	A lot of people answered redefinable characters, but that alone does
        not provide FULL-SCREEN graphics. 256 8*8 cells gives you a little
        over 1/2 of the screen in graphics, but the VIC has the ability to 
        make each character cell be 8*16, which gives enough pixels to map
        the entire default screen.

	How many cassette ports does the CBM 8032 computer have?

	Two.  One on back, one on side near the back.

	What 5 bytes must appear in every Commodore 64 autostart cartrdge and
   what location in memory must they be placed at?

	CBM80 at $8004.  The letters must have bit 7 set. So, the actual
        PETSCII codes are 195, 194, 205, 056, 048.
                     $c3, $c2, $cd, $30, $30 in HEX

	What is the correct Commodore technical term for "Sprites"?

	MOBs, or Movable Object Blocks.

	(Three parter, all parts must be correct)  "Push-wrap-crash" is a
        nickname for a condition that can lock up an old-style C=64. 
        What causes it? 
        How can it be avoided (besides not doing it)?
        What is the only way out once it has occured (besides rebooting)?

	Wow, I got so many responses to this!  This question actually
        dealt with a typical user, but people sent in descriptions of
        what the code does and how to patch it. So, there are two sets
        of answers to this:
    User Answer:
    1) If you put the cursor at the bottom of the screen and type 82 characters
       (not 81) and then trying to delete back to the 78th one.  
    2) Any of the following will work:
          Do not use the following colors for the cursor: red, blue, yellow, 
          light red, dark grey, light blue, light gray.
          Some people devised a IRQ wedge that will recover from the lockup.
          Have the following lines as the first lines of a program:
          10 open 15,8,15 
          20 input#15,a$
    3) There are actually two ways to recover.  They are:
          If you have a reset button installed on the 64, reset the machine,
          then load and run an unnew program.  (I accepted this, but I figured
          most people would assume this much)
          If you have a tape drive installed, press either Shift-3 or move a
          joystick installed in Port 1 in the UP direction.  Then, respond to
          the directions on the screen "PRESS PLAY ON TAPE". Next, press
          RUN-STOP to stop the tape load. 
    What really happens: (I can't prove this)
    1) The user types the line of text and the scroll code is invoked.
       The first two lines become linked as one logical line, and the
       third line is treated as a new line. 
       The user deletes the 82nd and the 81st character and then hits delete
       while in the first column of the third line.  Since the delete will put
       the cursor back up into the second line, which is linked with the first,
       the KERNAL gets confused and thinks the second line is at the bottom of
       the screen. Remember, the "cursor" is actually constructed by a
       combinations of using reverse characters and changing the color RAM
       nybble for that screen location.  Thus, when the cursor gets "erased"
       from the first column of the last line, the KERNAL thinks the color
       nyble for it is at $DC00, which is 40 bytes off from the actual
       position.  $DC00 is actually Port A for CIA #1, which is where the
       kernal writes the column of the keyboard it wishes to scan. Because the
       KERNAl is messed up, it puts the color nybble for where it thinks the
       cursor was into this location. (That is why there is a connection
       between cursor color and this bug.  
       Now, the system integrity has been compromised, but it does not show
       yet.  The user proceeds to delete the 80th character.  As the user
       deletes the 79th character, the bad value in $DC00 goes to work and
       fools the KERNAl into thinking SHIFT/RUN-STOP has been pressed.  It also
       pretty much disables the keyboard.  
    2) Since the Color RAM is what the KERNAl gets confused about, the solution
       was to not use certain bit patterns of colors:
          RED         0010
          CYAN        0011
          BLUE        0110
          YELLOW      0111
          LIGHT RED   1010
          DARK GRAY   1011
          LIGHT BLUE  1110
          LIGT GRAY   1111
          OK Colors:
          BLACK       0000
          WHITE       0001
          PURPLE      0100
          GREEN       0101
          ORANGE      1000
          BROWN       1001
          MEDIUM GRAY 1100
          LIGHT GREEN 1101
          All of the BAD colors have bit 1 set.  I have no idea what the
          significance of that is.
    3) You needed to get out of the tape load code, but you only had so many
       keys that were still active.  So, if you followed the directions on
       the screen, you could break out.  Since the tape load code uses CIA #1
       for its operations, it would take over the IC and then restore it
       to a correct state when either the load was stopped or the load
       completed.  Now, that is amazing!
       (Someone is free to check up on me concerning this, since I do not
        have a Rev 1 ROM to try out.  If someone has one, I would like to
        have a copy of it on disk or in email.  And if someone has the
        information on this bug from either the May 1984 Gazette p108, or
        from the COMPUTE! Toolkit Kernal VIC20/64, I would like a copy.)
New questions coming!
Jim Brain
[email protected]
10710 Bruhn Avenue
Bennington, NE  68007
(402) 431-7754


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