mdivancic Posted May 25, 2021 Share Posted May 25, 2021 Did Motorola ever make a 50mhz version in the PLCC package? Quote Link to comment Share on other sites More sharing options...
MasterMotorola Posted May 26, 2021 Share Posted May 26, 2021 Mike, yes Motorola made a 50Mhz 68882 FPU. I was considering getting one until I found out the CaTTamaran overclocks the FPU as well so there would really be no speed boost. More info on the speeds here near the bottom... https://en.wikipedia.org/wiki/Motorola_68881 Quote Link to comment Share on other sites More sharing options...
mdivancic Posted May 26, 2021 Author Share Posted May 26, 2021 11 hours ago, MasterMotorola said: Mike, yes Motorola made a 50Mhz 68882 FPU. I was considering getting one until I found out the CaTTamaran overclocks the FPU as well so there would really be no speed boost. The problem I’m having is my FPU is not stable over clocked. I have even tried a 40 mhz version, but no luck. I would love to find a 50 mhz version to fix this problem. Otherwise I will have to make a small mod and run my FPU at 32 mhz. Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted May 26, 2021 Share Posted May 26, 2021 Right with ya. I've got a 40mhz 68882 in my Pak 68/3 equipped STacy and in some of the benchmarking threads in other forums I was requested to run Nembench because of some odd results I got. Can't. It fails, so it seems I have a faulty 68882. (even though Gembench, and all the other software runs fine with no crashes. This includes software that uses an FPU. Go figure) Quote Link to comment Share on other sites More sharing options...
mdivancic Posted May 27, 2021 Author Share Posted May 27, 2021 21 hours ago, DarkLord said: Can't. It fails, so it seems I have a faulty 68882. More than likely it is not faulty, we are just trying to make it do something it was never designed to do. 1 Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted May 27, 2021 Share Posted May 27, 2021 3 hours ago, mdivancic said: More than likely it is not faulty, we are just trying to make it do something it was never designed to do. Be nice to think that but the testing software they asked me to use (NEMBENCH, by Douglas Little) works fine on other people's setups, including Pak boards... NEMBENCH is not benchmarking software per se - it actually tests the 68882/1, if I my understanding of it is correct.... (of course, I get things wrong all the time) Quote Link to comment Share on other sites More sharing options...
mdivancic Posted May 27, 2021 Author Share Posted May 27, 2021 4 hours ago, DarkLord said: Be nice to think that but the testing software they asked me to use (NEMBENCH, by Douglas Little) works fine on other people's setups, including Pak boards... NEMBENCH is not benchmarking software per se - it actually tests the 68882/1, if I my understanding of it is correct.... (of course, I get things wrong all the time) NEMBENCH looks like it’s just a benchmark program from a quick search of the forums. Can you step the speed of your setup down and test? I’m sure it’s a speed issue with the FPU. While there are plenty of people who run there FPU at 48mhz, there are many who can’t. My 33 mhz and 40 mhz FPUs both run for hours at 32 mhz. Neither will run at all at 48mhz. Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted May 28, 2021 Share Posted May 28, 2021 My bad...I've been running so many bench marking tests lately that I got NEMBENCH confused with FPUTEST. FPUTEST is the one that fails on my setup. It's supposed to test the FPU, not benchmark it. Sorry about the confusion. Unfortunately, with the Pak 68/3 boards, you are supposed to run the CPU and FPU at the same speeds. So I'm running the 68030 at 40mhz....you get the picture. With the Pak board, you change the CPU, FPU and oscillators, matching them all up to the same mhz. That's what's recommended. When/if I take my STacy apart I can play around with different speeds. Taking a STacy apart is not a light undertaking. Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted May 28, 2021 Share Posted May 28, 2021 I have only seen 50MHz in PGA. Max in PLCC I have seen is 40MHz. I don't think 50MHz was made in PLCC package. Quote Link to comment Share on other sites More sharing options...
mdivancic Posted May 28, 2021 Author Share Posted May 28, 2021 3 hours ago, snarkdluG said: I have only seen 50MHz in PGA. Max in PLCC I have seen is 40MHz. I don't think 50MHz was made in PLCC package. I kinda figured that... Quote Link to comment Share on other sites More sharing options...
mdivancic Posted May 28, 2021 Author Share Posted May 28, 2021 3 hours ago, DarkLord said: When/if I take my STacy apart I can play around with different speeds. Taking a STacy apart is not a light undertaking. As I well know... send me FPUTEST please. May as well test mine. Quote Link to comment Share on other sites More sharing options...
Chri O. Posted May 29, 2021 Share Posted May 29, 2021 (edited) Interesting FPU conversation. Does anyone knows if this will work in my Atari ST/e ( ICD AdSpeed STE 16MHz ). Can't find online manual for ICD AdSpeed STE ? Edited May 29, 2021 by Chri O. Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted May 29, 2021 Share Posted May 29, 2021 3 hours ago, Chri O. said: Interesting FPU conversation. Does anyone knows if this will work in my Atari ST/e ( ICD AdSpeed STE 16MHz ). Can't find online manual for ICD AdSpeed STE ? Probably yes. The 68882 is asynchronous and can have a different speed then the 68000. The AdSpeed for STe is missing the oscillator so you also need to fit that. So you could probably have 20MHz oscillator in there for the 68882. Or 32MHz or 50MHz if you have faster 68882. Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted May 29, 2021 Share Posted May 29, 2021 Hmm, what are you using to access the 68882? In my case, the Pak board has an option for a 68881/2. This ZIP should contain what you need for the AdSpeed: ADSPEED ST.ZIP Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted May 29, 2021 Share Posted May 29, 2021 8 hours ago, mdivancic said: As I well know... send me FPUTEST please. May as well test mine. Sure, hope yours is fine. fputest.zip Quote Link to comment Share on other sites More sharing options...
Lynxpro Posted June 4, 2021 Share Posted June 4, 2021 If I haven't asked this before, is there a list of programs for the ST/TT/Falcon that actually supports the 68881/2? Quote Link to comment Share on other sites More sharing options...
+DarkLord Posted June 5, 2021 Share Posted June 5, 2021 Let's start one. 1 Quote Link to comment Share on other sites More sharing options...
Chri O. Posted August 20, 2022 Share Posted August 20, 2022 Okay I'm sorry I bumped up old thread. Took me one year to get this FPU finally installed and all I see is few Atari ST/e bombs when I try to run DarkLord fputest prg. PIC Before FPU installation. NOTE: The 16 MHz clock was installed already (not sure if I did this back in the day 1990 ? ). PIC After FPU installation. Unfortunately does not seem to work, I'm guessing this is what you get when you buy stuff on eBay from China. 😒 ST/e MB. PIC. 2 Quote Link to comment Share on other sites More sharing options...
snarkdluG Posted August 20, 2022 Share Posted August 20, 2022 It doesn't look like you have pressed down the FPU far enough into the socket. 1 Quote Link to comment Share on other sites More sharing options...
Chri O. Posted August 20, 2022 Share Posted August 20, 2022 Hmm Ok I am going to remove the shielding and check it out thanks for pointing out. Quote Link to comment Share on other sites More sharing options...
Paul Westphal Posted August 22, 2022 Share Posted August 22, 2022 I have a MC688820A if anyone needs one. Quote Link to comment Share on other sites More sharing options...
Chri O. Posted August 30, 2022 Share Posted August 30, 2022 I pulled the trigger on new Motorola MC68882RC50A NXP Semiconductors in box from ebay. I hope this will work out better (Estimated delivery Tue, Sep 6 - Mon, Sep 12) 1 Quote Link to comment Share on other sites More sharing options...
Chri O. Posted October 30, 2022 Share Posted October 30, 2022 Okay so far no luck getting the FPU running on AdSpeed ST/e 😒 I really need to put this Atari 1040 ST/e back in its case. If there is anyone running the AdSpeed ST/e setup and has FPU running please let me know. Quote Link to comment Share on other sites More sharing options...
MasterMotorola Posted October 30, 2022 Share Posted October 30, 2022 Chri O., could it be that the software will only recognise a 68881 FPU and not a 68882? On a side note, I just noticed that your realtime clock is installed internally. Great idea! I always hated now much the ForgetMeClockII stuck out of the cartridge port. This mod may be the next thing I do to my STFM. Quote Link to comment Share on other sites More sharing options...
Chri O. Posted October 30, 2022 Share Posted October 30, 2022 At this point everything is possible but my last test was on brand new MC68881RC20B that came with the nice blue plastic holder (see the floppy drive). I'm probably going to look for more software to test this. I even removed the FPU and try to debug some of the traces and the 16Mhz clock signal on my oscilloscope. 1 Quote Link to comment Share on other sites More sharing options...
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