Ato
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Posts posted by Ato
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Well after searching around for the chip mfg logos I figured out that the previous post I made was linking to chips made by Freescale and ON Semiconductor. I assume they are the same as the Motorola mfg parts.
ON Semiconductor was part of Motorola and Freescale is what has become of Motorola. So it should be OK.
Cheers,
T.
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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.
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Email sent. Thanks!
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Definitely Bubble Bobble. Very addictive when played with a good friend.
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Just out of curiosity, what programs are known for working with the 68881 but not the 68882?
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.
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Ato, can you either post here or in PM where you've found $10 68882s @ 32Mhz? Thanks... The auction, ahem, that I'm "watching" ends in a couple of days and their price is $15...
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.
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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.
You're right about programmation, it's not so easy! I have written a FORTH interpreter/compiler and added recently the FPU support (because I found a 68882 for my MegaSTE). I have made a set of benchmarks that you can read on my page:
1) The paragraph "FPU Installation" shows the hardware part
2) A bit under, you'll find a paragraph about the FORTH benchmarks with and without the FPU. Even if there is a loss of time, the speed is really great!
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.
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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 MC68882@32 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.
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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.
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I opened the keyboard & removed all PCB screws & also all keys from the keyboard top.
It looks like there's a separate switch for each key, but I cant remove the PCB in order to get to them!
Any advice before I (possibly) do damage by experimenting?
I just refuse to believe this keyboard was built in a way that requires to desolder all switches to remove the PCB
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.
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So, I was using a 7800 joy pad in port 1. Thats what was making the keyboard mess up. If I had a mouse in port 0 and a 2-button 7800 controller in port 1 when I turned the power on, the keyboard acted crazy. I switched to a standard Atari joystick and all is fine.
And I was about to ask if your joystick had auto-fire on.
Cheers,
T.
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Again, it is correct for the purpose of formatting DOS compatible disks with the desktop, not for the purpose of writing ST images on the PC. As long as this is clear for the OP, then we are all happy
Absolutely.
Cheers,
T.
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Really too much incorrect and shallow writing here.
TOS version is not important in fact. You just don't format with Desktop formatter if want to use that floppy on PC. There is a lot of floppy formatting SW for Atari ST, so you may produce 100% POC compatible floppy.
FloImg works well on Vista and WIndows 7 - better said fdrawcmd is compatrible with them. Just get recent version.
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.
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Also the disk drive doesnt look like a stock drive. It is kinds loose in there and a little floppy.
That is certainly not the original floppy disk drive.
Cheers,
T.
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But the trouble is, when I log in, and I click "View unread posts," "View new posts," or "View active topics" I get a list of topics, similar to here at AtariAge, which is all good. But then when I click on any topic, I'm always at the first message of the darn topic again. I have to page/scroll to try to find where I was before, and sometimes that is not easy.
This works for me:
- Log in.
- Click on View unread posts
- Click on the little icon with the arrow next to the poster's name in the "LAST POST" colummn:
Hth.
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It's about games that have been "fixed" to work from hard drive! Please see that thread if you can help!
Posted a reply with valid URLs.
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Man, the above link from mimo is gone now. These are games that have been "fixed" to load from HD. Could somebody have a new link for this?
Thanks!
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The above D-Bug website no longer works. Anybody know if it's at a new URL? Was wondering about these games patched for TOS 2.06.
:(
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Is this not a little bit odd?
Why?
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Really looking forward to perusing this last BBS issue (not
that I would have any particular interest in BBSs, mind you)
Why on earth would one th- Eh! What's that sig saying again? Wait a second, didn't he just ...
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\Is there a simple way to run a European Atari 16bit machine here in the US?
Yes, there is. It is indeed the use of a transformer. I got one dirt cheap from Ebay: a 1kW model for about US$50. My GB-Falcon seems not to mind the 60 Hertz - the transformers transform voltage only, not frequency. Thought this should be explicitly mentioned in case somebody finds this post via a search engine. - and works great with the transformer.
Cheers,
T.
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Could not edit the post anymore: sorry, should have been quiet, not quite.
That's what I thought, the US version has a different PS.
Cheers,
T.
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Its Euro machine, will work on US power grid just fine, but you have to replace EUR power cord with US one.
And as it stands, this offer is still valid, if anyone is interested. Sorry I have been off for quite some time
Are you 100% certain that your Euro Falcon PS will work here in the US? Brad at Best in California sells two different PSes, one for Euro, one for US, both with different Atari part numbers.
And, oh boy, you have been quite for some(!) time. Welcome back!
Cheers,
T.
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I'd be interested in one for a MegaSTe
<unsolicited advice>You should express your interest through the posted forum link. This will guarantee that your request will be heard.</unsolicited advice>
Cheers,
T.
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in Atari ST/TT/Falcon Computers
Posted
I received mine on Tuesday, 26th. Looks awesome! Will try it out on the weekend.
Great work, Lotharek!
Cheers,
T.