From: brain@msen.com (Jim Brain) Subject: Commodore Trivia Edition #4 Answers Date: 13 Apr 1994 14:12:38 -0400 Organization: Brain Innovations, Inc. Lines: 185 Sender: brain@garnet.msen.com Message-ID: Reply-To: brain@mail.msen.com Here are the answers to Commodore Trivia Edition #4 for February, 1994. (And one errata) Errata for Trivia $028. Existing Trivia Entry from Commodore Trivia Edition #3: Q $028) Why was early Commodore equipment built into such heavy enclosures? A $028) Simple. Commodore made office furniture, which includes desks and filing cabinets. They simply used the facilities and parts on hand. Also, at the time the PET came out, people equated physical stability of a machine as an indication of its worth. Also, the system had to hold up the built-in monitor. Most people think it is due to FCC regulations. While that was indeed a factor, Commodore had experience with different types of shielding from the calculators they made. 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. I had sources that thought the FFC regulations were a factor, albeit not a big one, but I had my doubts. Discussions with Jim Butterfield proved my suspicions: FCC regulations hadn't come into being when the PET was designed, and I recall several engineers being pleased at their "accidental foresight" in designing a well-shielded machine. (Apple had BIG emission problems). But the keyboard assembly acquired quite a bit of plastic early on, so that the secondary shield become necessary. I suspect, but don't know, that Commodore was unsure about quantities in the earliest days of the PET, and found metal cases easier to manufacture and less likely to produce electrical hazards (with the CRT mounted within the frame). Revised Trivia Entry: Q $028) Why was early Commodore equipment built into such heavy enclosures? A $028) 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 monitor. 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. And now, the answers: Q $030) On a Commodore 64, what is the amount of RAM available for BASIC programs to reside in? A $030) Some people over-answered this question. The correct answer is 38911 bytes, which is what the BASIC screen says. Now, it is true that BASIC can use $C000-$CFFF, and some zero pages is easily used by BASIC, but it is non-trivial to get BASIC to use these areas. The math comes out to: $0801 (2048) to $9FFF (40959) - 1 (0 in location 2048). Please note that this is not the maximum size of a standard BASIC program, even if it does not use variables, since BASIC steals 3 bytes at the end of the program to determine the end. Q $031) Name one Commodore computer (pre-Amiga) that used two general purpose microprocessors? A $031) There are two (or more) answers to this question. The obvious answer is the Commodore 128, but the Commodore SuperPET (SP9000) had two, also. There was also an optional card to add another processor to the B-series. Note that some Commodore peripherals also had two (or more) microprocessors, but that is another question. Q $032) What are they? A $032) Commodore 128: 8502(6510 clone) and Z80. SuperPET: 6502 and 6809. B-series: 6509 and 8088. Q $033) Who was the Chief Executive Officer of CBM when the Commodore VIC-20 (VC-20) was introduced? A $033) According to my sources, it is none other than Jack Tramiel. While some claim Irving Gould as the man-in-charge since he have controlling interest at the time, the CEO was Jack. Whether he was in charge or not is left up to the reader. Q $034) the Commodore 64 and 128 (among others) have a TOD feature. What does TOD stand for? A $034) TOD = Time Of Day. The 6526 Complex Interface Adapter is the holder of the TOD clock, which can be used in lieu of the system jiffy system clock to time things, as it does not suffer from interruptions to service I/O and screen. Note that the standard kernal uses the system clock for TI and TI$, not the TOD clock. Q $035) What location in the Commodore 64 Kernal holds the version number? A $035) $ff80 (65408). Q $036) The first computer Commdore sold was the KIM-1. How much RAM was available on the KIM-1? A $036) 1.125K or 1024+128 = 1152 bytes. Q $037) Who designed the architecture for the 6502 integrated circuit? A $037) Chuck Peddle Q $038) What was the original name of the company that produced the 6502? A $038) MOS Technologies Q $039) What did the name stand for? A $039) MOS = Metal Oxide Semiconductor, which has three major families: NMOS: Negative MOS, PMOS: Positive MOS, and CMOS: Complementary MOS. MOS Technologies produced mainly NMOS ICs, hence the use of NMOS technology for the 6502 and 6510. Q $03A) Commodore acquired the company and renamed it to...? A $03A) CSG = Commodore Semiconductor Group. The renaming was not instantaneous, happening a number of months after the acquisition. Q $03B) The Commodore VIC-20 graphics were powered by the VIC-I (6560) integrated circuit. Was the chip designed for the computer, or was the computer designed for the chip? A $03B) The VIC-I 6560-61, was designed 2 years prior to the design of the VIC-20 computer. It was designed to be built into video games, but no one wanted to use it, so Commodore made their own system around it to recoop losses. Q $03C) The VIC-20 had a Video Interface Chip (VIC) inside it, yet that was not what the 'VIC' in the model name expanded to. What did it expand to? A $03C) VIC-20 = Video Interface Computer-20. The 20 was a rounding down of the amount of memory in the VIC: ~22K. Michael Tomczyk, who got stuck with the job of deciding on the name, did the rounding. Q $03D) The most widely known disk drive for Commodore computers is the 1541. how much RAM does the 1541 have? A $03D) 2048 bytes, or 2kB RAM. It is mapped at $0000-$07FF. Q $03E) On every Commodore disk, the drive stores a copy of the BAM. What does BAM stand for? A $03E) BAM = Block Allocation Map, or Block Availability Map. I am checking sources to figure out which one is the real McCoy. Q $03F) Now, for those into 6502 machine language. What instruction was not available on the first 6502 chips? A $03F) ROR (ROtate Right) was not available until after June, 1976. However, all Commodore VICs and C64s should have this instruction. Some people gave instructions that are found on the 65c02, designed by Western Design Center, and licensed to many companies. However, the 65c02 itself occurs in two flavors, and neither are used in any stock Commodore product I know of. Jim Brain -- Jim Brain, Embedded Systems Designer, Brain Innovations. brain@msen.com Dabbling in VR, Old Commodore Computers, and Good Times! "The above views DO reflect my employer, since I am my employer" - Jim Brain