Oswald

few things are missing: one timer could count the restarts of the other timer, and timers could count outer signals.

They have a sync serial-port function which is not used and a time-of-day clock function which isn't particularly useful (though some games do use it 'cos it's there). What else do they offer that the VIA does not? Parallel I/O The CIA had two 8-bit bidirectional parallel I/O ports. Each port had a corresponding Data Direction Register, which allowed each data line to be individually set to input or output mode. A read of these ports always returned the status of the individual lines, regardless of the data direction that had been set. [edit] Serial I/O An internal bidirectional 8-bit shift register enabled the CIA to handle serial I/O. The chip could accept serial input clocked from an external source, and could send serial output clocked with one of the built-in programmable timers. An interrupt was generated whenever an 8-bit serial transfer had completed. It was possible to implement a simple "network" by connecting the shift register and clock outputs of several computers together. [edit] Handshaking Two dedicated control lines (/FLAG and /PC) were implemented to allow coordination between multiple CIA chips. These lines, along with 8 of the 16 available parallel port data lines, made it possible to use the CIA as a simple, Centronics-compatible line driver. [edit] Interval timers Two programmable interval timers were available. Each timer consisted of a 16-bit read-only presettable down counter and a corresponding 16-bit write-only latch. Whenever a timer was started, the timer's latch was automatically copied into its counter, and the counter would then decrement with each clock cycle until underflow, at which an interrupt would be generated. The timer could run in either "one-shot" mode, halting after the first interrupt, or "continuous" mode, reloading the latch value again and starting the timer cycle anew. In addition to generating interrupts, the timer output could also be gated to the second I/O port. [edit] Time-of-Day (TOD) Clock A real-time clock is incorporated in the CIA, providing a timekeeping device more conducive to human needs than the microsecond precision of the interval timers. The TOD clock consists of four read/write registers: hours (with bit 7 acting as the AM/PM flag), minutes, seconds and tenths of a second. All registers read out in BCD format, thus simplifying the encoding/decoding process. Reading from the registers will always return the time of day. In order to avoid a carry error while fetching the time, reading the hours register will immediately halt register updating, with no effect on internal timekeeping accuracy. Once the tenths register has been read, updating will resume. It is possible to read any register other than the hours register "on the fly," making the use of a running TOD clock as a timer a practical application. If the hours register is read, however, it is essential to subsequently read the tenths register. Otherwise, all TOD registers will remain "frozen." Setting the time involves writing the appropriate BCD values into the registers. A write access to the hours register will completely halt the clock. The clock will not start again until a value has been written into the tenths register. Owing to the order in which the registers appear in the system's memory map, a simple loop is all that is required to write the registers in the correct order. It should be noted that it is permissible to write to only the tenths register to "nudge" the clock into action, in which following a hardware reset, the clock will usually start at 1:00:00.0 AM. In addition to its timekeeping features, the TOD can be configured to act as an alarm clock, by arranging for it to generate an interrupt request at any desired time. Due to a bug in many 6526s (see also errata below), the alarm IRQ would not always occur when the seconds component of the alarm time is exactly zero. The workaround is to set the alarm's tenths value to 0.1 seconds. The TOD clock's internal circuitry is designed to be driven by an AC input signal, either 50 or 60 Hz, as would be derived from the mains power source, resulting in a stable timekeeper with little long-term drift. The ability to work with both power line frequencies allowed a single version of the 6526 to be used in computers using either the NTSC or PAL video standards. The 8520 revision of the CIA, used in the Amiga, modified the time-of-day clock to be a 24-bit binary counter, replacing the BCD format of the 6526. Other behavior was similar, however.

I will try to put my answers to the same level of sense as yours. Hope you will understand them now: >c64 has two CIA chips which are successors of the PIA chip. >So does the Amiga. Amiga CIA run faster than your C64 CIAs. PIA is faster than the way the CIAs are done on your C64 and as I already stated >you can do byte input with one LDA on Atari from the joystick ports. The PC has even better peripheral chips than the amiga. >1.79 > 1.0 cpu., 1.7897 timing frequency > 1.022 frequency,Faster graphics updates, thats the same argument 3 times. No, you left out the word POKEY in the second frequency. This I already replied to from Vigo, you must have missed it. POKEY timer frequency is accurate to 1.7897Mhz. It also does up to 20Khz 4-bit samples as I already mentioned. The Amiga has a better sound chip than the pokey, its even faster. does 32khz samples in 8 bit. 4 channels, own dma, yaddayadda. >but I can list proofs the same stupid way like you, here: etc etc (SID) etc etc more sprites etc etc (CIA) etc more colors without trick, etc etc etc (VICII) etcetcetc. :D these are your arguments. No, the Amiga has better graphics. If you think it's stupid to compare hardware performance of chips, then I would disagree with you on that. Otherwise, counter the point with a superior performance number that you think your C64 does for the given chip. The amiga outdoes a8 in anything, look at it chip level performance or as a whole doesnt matter.

oh right. this means atari pmgs are better than the c64s sprites. thanks for making it clear. You stated that "ALL" games with c64 sprites can do much better so I refuted that. Your not giving any credit to Atari sprites for length and color as if they are immaterial. show me a game which can do better with atari sprites.

check the specs.

The reason the disk routines don't blank the screen is that Commodore decided it was better to have the system be incompatible with the 1540 and require people to use the 1541 at a much lower speed, than to blank the screen while loading. nope. it was not poor engineering and such stupid decision as you may think. simply there were a lot of things going wrong with it:VIA chips were faulty, parallel lines optimised away from motherboards by mistake, and finally jack tramiel yelling at robert russel that he wants to see a working 1541 on his desk in a week.

blanking the screen is the weakness of the built in horrible tape loader it is not something you must to do, and the stock disk routines doesnt blank it to begin with. check this: tho you would better check it in emulator, and monitor the drive led while the demo is running to see that the c64 can load while displaying demo effects AND playing music. no need to blanking the screen or add some primitive screenmodes. at some scenes there are sprites multiplexed, background colors changed, digi played, at the same time WHILE loading. (countdown scene with spaceship+melon) That means C64 have his own ways. that means C64 can do disk IO while doing zillion of other things aswell, something thats the A8 has never seen so far. the point is that the c64 doesnt needs HW addons to make a trackmo. In fact atari trackmos are not trackmos. they are signleload onefile demos. The point is that it runs on the stock setup. What I dont see no point in is upgrading old HW. if its not good enough for you than use a mac/pc.

c64 has two CIA chips which are successors of the PIA chip. PIA=peripheral interface adapter, CIA = complex interface adapter. Do I must to copy here the specs which show why is the CIA superior, or you can google it yourself ? or everything that has less functions from now own according to you is better because its easier to use ? then the best 8 bit homecomputer must be the kim1. 1.79 > 1.0 cpu., 1.7897 timing frequency > 1.022 frequency,Faster graphics updates, thats the same argument 3 times. but I can list proofs the same stupid way like you, here: etc etc (SID) etc etc more sprites etc etc (CIA) etc more colors without trick, etc etc etc (VICII) etcetcetc. :D these are your arguments. "Obviously, you did not read the post that you hurriedly replied to." can you tell me the next weeks lottery numbers aswell ?

oh right. this means atari pmgs are better than the c64s sprites. thanks for making it clear.

it used a banking method using the 8722 mmu chip. I doubt there were homebrew ram upgrades, as C= sold REU's itself. (Ram Expansion Unit). http://www.google.hu/search?hl=hu&q=87...3%A9s&meta= click the first link, I can not open it for some reason now, I hope that pdf helps.

I stated that if you keep repeating "more colors" as your argument, then it's better to get an IBM PC. You want to prove that the hardware in Atari is superior than c64, you'll have to beat the functionality of VICII, SID, CIA1, CIA2, 1Mhz CPU, etc. If most of your software only utilizes "more colors", that does not make it's hardware superior to the c64. And I WAS comparing hardware...

as there are simply more c64 users and c64 fans out there most people would agree that the c64s are and were better. thats the reality my friend. You have to know both machines before you can decide. You apparently don't. what you have said is:"most people would agree that the Ataris are and were better machines than C64/128". you havent said that all these people have to know both machines aswell. I can do this retarded way of arguing aswell: the XBOX is faster than the Atari's cpu if you ever make argument of speed. and all the games with c64's sprites can do much better.

blanking the screen is the weakness of the built in horrible tape loader it is not something you must to do, and the stock disk routines doesnt blank it to begin with. check this: tho you would better check it in emulator, and monitor the drive led while the demo is running to see that the c64 can load while displaying demo effects AND playing music. no need to blanking the screen or add some primitive screenmodes. at some scenes there are sprites multiplexed, background colors changed, digi played, at the same time WHILE loading. (countdown scene with spaceship+melon)

yeah, poor c64 colors are out of an unreal color palette After seeing all of your posted pictures, it seems to be the best description. which brings us back to the speccy level: "my colors are nicer than yours" well farewell I had enough of this bullshit for this year

yeah, poor c64 colors are out of an unreal color palette

What is wrong with that sentence, in your opinion? that the real advantage is speed and not memory saving.

i started playing with Z80 about a month ago, the way it accesses memory was... well okay i know there's bias because i've been coding 6502 for so long, but it feels very long winded, almost like trying to do everything with indirect indexed addressing. 6502 is very primitive, in fact chuck peddle said they never intended it to be used in computers, but in intelligent electronic devices like printers, point of sales, etc. if you look at 680000's or the x86's they all do it in the same style z80 does: the idea being: memory is slow, manipulate data inside the cpu registers.

nope. the main advantage is that you can implement algorithms more efficiently due to more and/or wider registers, you can add 16 bit wide numbers inside the cpu, better stack, more sophisticated instruction set etc etc etc. add hl,de to do the same thing on 6510 you do: lda $10 clc adc $20 sta $20 lda $11 adc $21 sta $21 a "bit" less efficient isnt it ?

oh, thanks for clearing me up

2Mhz 6502 is equivalent to 4Mhz Z80. Even sometimes better, if we consider the real direct translate coding of last games JET SET WILLY or JET PACK. I dont think so. for example a 16 bit addition takes up more instructions on the 6510 as than on the z80. while you can manipulate 16bits as one with the z80 you have to broke it down to 8 bits on 6510, which is a very big disadvantage. not to speak about the more registers AND two register sets. z80 is a much better cpu than the 6510.

you dont need to be a musician to make a non detuned music. (atleast thats how it works on the c64) you have the exact formula that what value is what musical tone and thats about it....

Those pictures look really impressive. Well, those are only reduced Photos. Just for showing what it means to have 16 colours fully available for an image. Possibly, you can reach good results when showing them on a plus 4 yeah and this is what the c64 can do, tho this is not a reduced photo like your one:

horribly detuned its hurts to listen to it sorry. the sounds are really good for the pokey, but the detuning hurts so much man its hard to bear it. and even with the relatively good sounds for a pokey doesnt sounds anything near to a sid.. proves analplexers stupid statements wrong. (sid can do anything a pokey can)

the c64 can do 16million textured polys with a shader. if you need proof of concept its your problem. I dont have the time to look for examples just to convince you. It's a waste of time. What I stated is based on my own experience with c64. If you don't believe me, that's your choice, but not my problem.

oh then what does this sentence mean: it does mean that the pokey is not better? no matter how hard I try it means: pokey can do anything the sid can do and more = better. oh, how about 16 bit pulse widths, the SID's mixed waveforms, 3 channels all with 16 bit frequencies, how about ADSR without cpu intervention ? how about ring mod, sync, filtering coming in signal? the pokey can not do shitloads of things the sid can do. ah this is getting awesome!!! this is more stupid than any spectrum fan can reach in its wildest dreams but its your turn, now show me the c64 doesnt has: - built in phong shading - built in gourad shading - 2000x2000x16m gfx mode - 256 channel sound - 6 gigs ram - hdd ide/sata - etc -..