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Commodore Trivia 17
-------Commodore Trivia Edition #17 Questions and Answers Preface--------
Not to leave you in the dark for too long, here are the trivia
answers to the previous edition of Commodore Trivia. I am posting the
answers at this time, and will post the scores and winners in a few
days. This time frame is set up to allow time for any discussions on the
correctness of these answers. By this time, the newest edition of
trivia has been posted. I encourage you to enter it.
This edition of trivia answers has been posted to the USENET newsgroups:
comp.sys.cbm, alt.folklore.computers, and comp.sys.amiga.advocacy. It
has also been posted to the FidoNET CBM Echo.
Feel free to use these trivia answers in newsletters, magazines, and other
publications (please see disclaimer). If you use the trivia, I would
appreciate knowing where it has ended up. If you intend to use this
information, please wait a few days after the posting date to allow for
major errors to be corrected.
Please mail any new questions for upcoming trivia (with answers) to my
address.
This edition and previous editions the trivia can be obtained from my
mailserver.
To: brain@mail.msen.com
Subject: MAILSERV
Body:
send trivia1
quit
This will retrieve the first edition of the trivia. Replace the
number with the edition you want.
-------Commodore Trivia Edition #17 Questions and Answers (BEGIN)--------
Q $100) On the MOS Technology's KIM-1, how many keys were on the keypad?
A $100) 23 keys. The keypad has room for 24, but one spot is taken by
a switch that puts the system into single-step mode. Interestingly,
some pictures have the switch on the upper left, some on the upper
right.
Q $101) The KIM-1 keypad had the common 0-9A-F keys on the keypad, but
also had some special keys. Name them.
A $101) GO (Go) Executes an instruction and displays the address of next,
ST (Stop) Stops execution of program and return control to monitor,
RS (Reset),
AD (Address) Address entry mode,
DA (Data) Data entry mode,
PC (Program Counter) Displays and restores program counter to values
in PCL and PCH,
+ (Increment) Increments the address without changing the entry mode.
Q $102) The KIM-1 was a set of modules that could be plugged together to
expand the system. Each module had a model number. What was the
model number of the KIM-1 motherboard?
A $102) The KIM-4.
Q $103) On the 1525 line of printers, if you wanted to create the following
graphic, what bytes would you send to the printer after turning on
graphics mode?
****
* *
* *
* *
* *
* *
****
A $103) I guess I should have stipulated that this is a bitmap. ASCII just
has a few limitations. Anyway, the correct bytes to send are:
255, 193, 193, 255. You got these by assigning each bit in a column
a value, and adding 128 to the result for each column.
Q $104) What is the horizontal resolution of the 1525 line of printers?
A $104) Character resolution: 80 chars, or 10 chars/inch (cpi).
Graphics resolution: 480 dots, or 60 dots/inch (dpi).
Q $105) On Commodore drives, explain the difference between the B-R command
and the U1 command.
A $105) The two commands read in data from a disk sector. However, the
U1 command always reads a full sector (255 bytes). The B-R
command reads the number of bytes specified in the first byte of
the sector. If the first byte is a 15, B-R will read 15 bytes
from the sector. (From the 1581 manual)
Q $106) On the Commodore 1541 drive, what does the U: command do?
A $106) This command has been traditionally used to reset Commodore drives,
including the CBM 1541. However, some early versions of the Drive
DOS did not correctly handle this command. In these versions, the
drive and computer failed to complete the command transaction
successfully, and what looked like a hung machine resulted.
Commodore later fixed this problem. If U: seems to not work on
your drive, try U; instead.
Q $107) What does the first routine in the 1541 drive ROM actually do?
A $107) The function, called SETLDA and residing at $C100, turns on the
drive active LED for the current drive. The routine loads the
current drive from $7F and sets bit 3 of DSKCNT ($1C00).
Q $108) How many files will a 1581 disk drive hold?
A $108) 296 files. Note that it is not a multiple of 144.
Q $109) Commodore 1581 drives have a special "autoboot" feature that enables
the drive to load and run a program off a disk upon drive bootup.
What is the required name of the file?
A $109) COPYRIGHT CBM 86
Q $10A) What filetype must the file mentioned in $109 be?
A $10A) USR.
Q $10B) To power up a 1351 mouse in "joystick mode", what must the user do?
A $10B) If one depresses the right mouse button during power-up, the 1351
will behave just like a joystick.
Q $10C) Describe the contents of the POTX or POTY registers when using a
1351 mouse.
A $10C) Each register holds the same type of information, just for a
separate axis, so we will describe just one register:
Bit: Function
7 Don't care
6-1 Mouse axis position mod 64.
0 Noise Bit. (check this bit to see whether mouse has moved)
Q $10D) Commodore computers typically use most of zero page for temporary
variables and other items. However, both the VIC-20 and the 64
reserve 4 bytes for user programs that need zero page memory. Where
are these locations?
A $10D) $FB-$FE (251-254). I am not sure these were "reserved" for
programmers as much as they were just not utilized by the
CBM programmers.
Q $10E) Name the 16 colors available on the 64.
A $10E) Black
White
Red
Cyan (Light Blue-Green)
Purple
Green
Blue
Yellow
Orange
Brown
Light Red
Dark Gray (Gray 1)
Medium Grey (Gray 2)
Light Green
Light Blue
Light Gray (Gray 3)
Q $10F) Both the VIC-20 and the C64 emulate the operation of the 6551 UART.
How many "mock 6551" registers are mapped into the memory map?
A $10F) 5, from $293-$297 (659-663). The register contents:
$293 6551 Control Register
$294 6551 Command Register
$295-6 6551 User Defined Baud Rate value.
$297 6551 Status Register
The information in this between the lines marked by (BEGIN) and (END)
is copyright 1995 by Jim Brain. Provided that the information
between the (BEGIN) and (END) lines is not changed except to correct
typographical errors, the so marked copyrighted information may be
reproduced in its entirety on other networks or in other mediums. For
more information about using this file, please contact the address
shown below.
Jim Brain
brain@mail.msen.com
602 North Lemen
Fenton, MI 48430
(810) 737-7300 x8528
--------Commodore Trivia Edition #17 Questions and Answers (END)---------
