-------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)---------