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  Amazing site of C64 SID remixes

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)


	The company that produces The Big Blue Reader, a program that allows
        reading and writing of IBM formatted disk in 1571s and 1581s, is
        called SOGWAP.  What does SOGWAP stand for?

	Son Of God With All Power.  They also market the Bible on diskettes.

	What version of DOS does the Commodore 8280 8 inch dual drive have?

	The 8280 has version 3.0.  Many have not ever seen this IEEE-488
        compatible drive used on some PETs.  It has the same DOS version
        that is in the D90XX hard drives, and could read 250kB and 500kB
        IBM formatted disks, as well as some CP/M formats.  Note that although
        this version number is used on the 1570/71 disk drives, the code is

	What was the color of the original Commodore 64 case?

	Some early versions of the Commodore 64 were housed in VIC-20 color
        cases, so off-white is the correct answer.

	On an unexpanded Commodore 64, how does one read the RAM
        locations $00 and $01?

	Well, you cannot do so with the CPU directly, since it resolves these
        locations into internal addresses.  However, the VIC II can see these
        addresses as external memory.  So, just make one spritexs with the
        first bit in the sprite set, and move it over the first two bytes, 
        pretending they are part of a bitmap.  By checking the sprite-to-
        background collision register, you can tell if the bit in the byte is
        set.  Email me for a more complete description. 
        Sven Goldt and Marko Makela get credit for this answer and the next.

	On an unexpanded Commodore 64, how does one write the same locations?

	It seems the 6510 generates a valid R/W signal any time it does an 
        internal read or write.  This is to be expected, since the 6510
        internal registers were grafted onto a 6502 core processor.  
        Howevere, the address lines are also valid during any internal read
        or write, since failure to do so may write the data on the data bus
        to some invalid address.  The data on the bus, however, comes not from
        the CPU, but from residual effects of the data last read of written by
        the VIC chip.  Thus, by programming the VIC chip to read data from
        some known location, and by placing relevant data in that location, a
        write to location $00 or $01 will place the data from that last read
        VIC location into $00 or $01.  This is usually accomplished by placing
        the data to be written out into location $3fff, which the VIC fetches
        during the time the border is being displayed.  By triggering a
        routine when the raster hits the bottom border, you can copy location
        $3fff to $00 or $01.

	What is 'CB2 Sound', and on what computers was it popular?

	This is the sound made by sending square out of the 6522 IC on some
        Commodore computers.  It is called 'CB2', since that is the name of
        the pin on the 6522 that outputs the waveform.  I won't go into a
        complete description, except to say that most models of the PET
        had the capability, and most PET owners used it as the ONLY sound
        source, since the PETs did not have a sound chip.  Although the VIC
        did have some sound capabilities, by that time Commodore had 
        realized its widespread use and included some information on it in
        the Commodore VIC-20 Programmer's Reference Guide.  For more info,
        reach for your nearest VIC PRG and look at page 232.

	in question $021, the Batteries Included logo description was asked
        for.  Now, what is the name of the man in the logo?

	"Herbie"  Jim Butterfield supplied me with this one.

	Why was the Commodore VIC-20 produced with so many 1K chips in it?
        (Hint: it had little to do with the cost of SRAM at the time)

	Jack (Tramiel) decreed that Commodore had a surplus of 1K chips,
        so he didn't care how much memory it had, as long as the designers
        used 1K SRAMs.

	What does ADSR stand for?

	ADSR = Attack, Decay, Sustain, Release.  These are the four values
        specified to define a SID waveform envelope.

	In question $035, it was learned that the Commodore 64 kernal
        revision number is stored at $ff80 (65408).  Now, what is the number
        stored there for:
        a) The first revision?
        b) The PET64 (4064)?

	a) 170. (Yep, this was prior to 0!)
        b) 100. (The PET 64 uses this value to adjust the startup logo

	Who was the mastermind behind the original Commodore Kernal?

	John Feagan.  He had intended it to provide upward compatibility
        for future computer systems.  Unfortunately, the kernal was
        modified enough with each new computer system, that the idea of
        compatibility never really surfaced.  Still, it was a nice try.

	Who designed the first VIC prototype?

	There are two answers to this question.  At the time, the VIC had no
        name and was called the MicroPET or No Name Computer.  Jack Tramiel
        wanted to show some prototypes of the VIC at the 1980 Comsumer
        Electronics Show (CES).  The funny thing is, he got not one
        prototype, but TWO.  Bob Yannes, working against time, had hacked
        together a minimal working prototype using spare PET/CBM parts.
        Another prototype, brought to the show by Bill Seiler and John
        Feagans, had been put together after some preliminary discussions
        with Yannes.

	How many pins does a Commodore 1525 printhead have in it?

	Trick Question.  The two 1525 printers I have show that the 1525 
        printhead has but one pin.  The seven dots are created by a revolving
        7 sided star-wheel for the platen, which presses the paper against the
        printhead in the seven different dot locations.

	Why does mentioning a PET computer in France make people chuckle?

	PET means "FART" there.

	What interface IC is used to drive the IEEE-488 bus in a PET computer?

	A 6520.  It is appropriately called a PIA (Peripheral Interface

	What was the primary reason Commodore went to a serial bus with the
        introduction of the VIC-20?

	Jim Butterfield supplied me with this one:
        As you know, the first Commodore computers used the IEEE bus to
        connect to peripherals such as disk and printer.  I understand that
        these were available only from one source:  Belden cables.  A
        couple of years into Commodore's computer career, Belden went out
        of stock on such cables (military contract? who knows?).  In any
        case, Commodore were in quite a fix:  they made computers and disk
        drives, but couldn't hook 'em together! So Tramiel issued the
        order:  "On our next computer, get off that bus.  Make it a cable
        anyone can manufacture".  And so, starting with the VIC-20 the
        serial bus was born.  It was intended to be just as fast as the
        IEEE-488 it replaced.  
        And it would have been, except dor one small glitch.  But that is
        another trivia question.

Jim Brain
[email protected]
10710 Bruhn Avenue
Bennington, NE  68007
(402) 431-7754


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