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Ato

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About Ato

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  1. I received mine on Tuesday, 26th. Looks awesome! Will try it out on the weekend. Great work, Lotharek! Cheers, T.
  2. ON Semiconductor was part of Motorola and Freescale is what has become of Motorola. So it should be OK. Cheers, T.
  3. I just received an email from Lotharek. Preordering is now possible on his page http://lotharek.pl/product.php?pid=73 and I have already placed my order. Cheers, T.
  4. Definitely Bubble Bobble. Very addictive when played with a good friend.
  5. I hope that you are still interested in a reply. :-) - Most importantly: the 68881 and 68881 are pin-compatible and have identical programming models. Meaning that in user mode it does not matter which one is used, the software won't be able to tell the difference. - An internal difference is that the 68882 has an additional conversion unit which takes care of converting data into the internal extended format. This allows for fmove instructions to be executed concurrently with transcendental or arithmetic instructions. There are strict guidelines about how to optimise code so that the execution time benefits from the conversion unit of the 68882. For best performance one should unroll loops, avoid FPU register conflicts and execute slow fmove instructions right after slow arithmetic instructions (or transcendental) in order to hide the execution time of the fmove. Cutting to the chase that means that if the software is done right, the 68882 will be much faster than the 68881 at the same clock speed since it does not spend clock cycles waiting for new data while concurrently calculating stuff. - The frame state sizes which are stored by fsave differ: null frames are of identical size, idle frames are 28 and 60 bytes, busy frames are 184 and 216 bytes. The 68882 uses the 32 additional bytes to store the state of the aforementioned conversion unit in the frame. This is a reliable way to distinguish between the 68881 and the 68882 in software. Execute the following subroutine in supervisor mode: ; This Subroutine returns true in d0 when an MC68882 is installed, ; false otherwise. testMc68882: move.l d1, -(sp) moveq.l #0, d0 moveq.l #0, d1 fsave -(sp) move.b 1(sp), d1 cmp.b #$18, d1 beq.s is68881 moveq.l #1, d0 .is68881: frestore (sp)+ move.l (sp)+, d1 rts Source: MC68881/68882 Floating-Point Coprocessor User's Manual, 2nd ed., 1989, Prentice Hall Cheers, T.
  6. Currently on "YouKnowWhereToBid": 140677848981 290656172263 220846013303 w. price suggestion Simply look for "68882" and you'll always find cheap FPUs. Sometimes they are defect, sometimes they are only 16MHz. Sometimes you'll find 40MHz gems.
  7. The name of the extension card is Atari SFP004. Installation manual: http://www.atarimania.com/documents/atari_68881_co-processor.pdf and some pictures: http://www.maedicke.de/atari/hardware/sfp004.htm And I have to apalogise because I was wrong. It was not a ROM-port card but one for the Mega-ST internal 68000 expansion bus. Sorry again for the wrong information. Whoopsy Daisy! Quite some improvement. Would be really nice if you could add support for the FPU-on-a-card for later comparison if we find somebody who has got one. :-) Cheers, T.
  8. Neither the ST models nor the plain STE models nor the Mega ST - caveat: not the Mega STE models! - would come with a plain socket for any of the MC68881/2. In order to provide hardware FPU support to hose models, they would have to be upgraded with the Atari FPU card. - Or whatever its name is. - Anyway, the Atari FPU upgrade card has one major disadvantage. It cannot be programmed directly, i.e. by using proper FPU mnemonics, but one has to program it by writing all the commands and data into memory mapped registers which obviously sucks big time due to the timing (ROM port!) and the usability constraints. But since an [email protected] MHz is available for just US$10 or max. US$15 on "YouKnowWhere", there is no reason to not get one. And the general assumption is correct, that most Atari software does not make use of it, since, at the time of the development of most of the software, those FPUs were just (expletive omitted) expensive and hence not available to the developers. Hth. Cheers, T.
  9. Ijor: software is never finished, it is never where you want it to be. Following your line of argumentation, then you will never release any source code. This is seconded by your statement that you have even less time now to work on implementing the latest ideas. Quite a conundrum you got at your hands. :-) If it is about source code, nothing beats "release early, release often". Make a git repository available and let other capable software developers help out! Cheers, T.
  10. Sorry for the late reply. Usually you can pop off the PCB after you unscrewed all tiny screws - about a gazillion or so. Cheers, T.
  11. And I was about to ask if your joystick had auto-fire on. Cheers, T.
  12. Dude, the TOS version is important if one wants to format a DOS compatible floppy disk through the GEM desktop without any additional software. The previous writer is correct to point TOS 1.04 out as minimum requirement. Cheers, T.
  13. That is certainly not the original floppy disk drive. Cheers, T.
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