D88.R-WESTMAN@linus.ida.liu.se (Rickard Westman) (09/27/89)
*** About 2 months ago, I posted a message to comp.sys.amiga, where I asked for some tips on improving my A1000's reliability with devices on the expansion bus. Since I lost my access to News soon after that, I couldn't see if there was any response. Therefore, I apologize when I bring this up again. *** Ever since I decided to get a hard disk for my Amiga 1000, I've had problems. The first hard disk I tried was returned for several reasons, one of them being that my Amiga had spurious Gurus when the hard disk was connected. Most of the time it worked though, but it was painfully slow (much slower than the manufacturer claimed that it would be). My second attempt was with a GOLEM HD3000. Now really weird things started to happen. It would _not_ work with my expansion memory (an old XpanderII 2 meg box). When I had my expansion memory connected to the pass-thru on the interface, my Amiga even refused to load Kickstart. It did initialize the keyboard, and flashed the power LED, but then it was dead. Specifically, it did not change the screen color from "very dark gray" to "medium dark gray" as it normally does after 1-2 seconds. The strange thing was, that the same thing happened when I removed the memory board from the bus, and just let the box be connected to the interface. This box does *nothing* with the signals from the 86-pin-connector, apart from connecting GND-pins with each other. To be sure, I also tried this with another unpopulated "connector card". The same thing happened with that one. Incidentally, I found out that this would also happen with the interface connected (but not the expansion box) when the big metal shield that normally is above the motherboard, was removed! When I put it back - everything would work. When I removed it - my Amiga was as good as dead again. I tried to put the shield back on, loading Kickstart, and then remove it again. I was surprised to see that everything worked fine. I used the machine for several hours with the shield removed. No problems at all, until I rebooted - then it hang. Apparently there is _something_ that makes the Amiga fail its self-test, but that does not impair its normal operation. What could this be? After all the code in the boot-ROM does not try to configure anything on the expansion bus - so I guess the problem must be of "electrical" nature. I read something here in comp.sys.amiga about changing the normal 68000 against a Motorola 68000, supposedly with higher drive capacity. I tried to exchange my Thompson 68000 against a Motorola part, but this actually made the problems worse. Now the hard disk interface couldn't be connected at all, even though the shield was in place and it was alone on the bus. The symptoms were the same as I've described earlier. With a Signetics 68000, my Amiga refused to work at all! It hang in the same way as usual - the 68000 was apparently operative enough to flash the power- LED, but once again the self-test failed. This 68000 couldn't even drive my Amiga alone! Switching back to the Thompson 68000, everything worked again, except hard disk interface and exp. memory at the same time. All these tests were made several times, with consistent results. My setup: Amiga 1000 with internal 256K expansion. It does not have a daughter-board, everything is on the motherboard. Very simple hard disk interface, no auto-config stuff, just one PAL, and two 74LS ICs. The pass-thru traces (you know what I mean even if that is the wrong word) on the board are approximately 3 inch, and they are not buffered in any way. All signals just pass through the interface. XpanderII box with or without a 2MB card. A few questions: Is this normal behaviour for an A1000, or should it be able to drive more than one expansion device, without extra drivers/buffers? Is it considered to be bad design, if you pass the bus through, without extra drivers/buffers when the product specifically is for the A1000? Are there such great differences between 68000's, as my tests seem to indicate? Is poor grounding typical for A1000's, even those without daughterboards? Which signals on the expansion port could be "flakey" enough to make the self-test fail, but still make it possible to run the Amiga as usual after the boot succeded? Is there anything constructive I can do about this, or will I never be able to use a second exapnsion device with my Amiga? Hmmm... A lot of questions - I do not know much about these things - I would appreciate it _very_ much, if someone helped me out. --------------------------------------------------------------------------- Richard Westman | University of Linkoping |*** About 2 months ago, I posted a message to comp.sys.amiga, where I asked for some tips on improving my A1000's reliability with devices on the expansion bus. Since lost I lost my access to News soon after that, I couldn't see if there was any response. Therefore, I apologize when I bring up this subject again. *** Ever since I decided to get a hard disk for my Amiga 1000, I've had problems. The first hard disk I tried was returned for several reasons, one of them being that my Amiga had spurious Gurus when the hard disk was connected. Most of the time it worked though, but it was painfully slow (much slower than the manufacturer claimed that it would be). My second attempt was with a GOLEM HD3000. Now really weird things started to happen. It would _not_ work with my expansion memory (an old XpanderII 2 meg box). When I had my expansion memory connected to the pass-thru on the interface, my Amiga even refused to load Kickstart. It did initialize the keyboard, and flashed the power LED, but then it was dead. Specifically, it did not change the screen color from "very dark gray" to "medium dark gray" as it normally does after 1-2 seconds. The strange thing was, that the same thing happened when I removed the memory board from the bus, and just let the box be connected to the interface. This box does *nothing* with the signals from the 86-pin-connector, apart from connecting GND-pins with each other. To be sure, I also tried this with another unpopulated "connector card". The same thing happened with that one. Incidentally, I found out that this would also happen with the interface connected (but not the expansion box) when the big metal shield that normally is above the motherboard, was removed! When I put it back - everything would work. When I removed it - my Amiga was as good as dead again. I tried to put the shield back on, loading Kickstart, and then remove it again. I was surprised to see that everything worked fine. I used the machine for several hours with the shield removed. No problems at all, until I rebooted - then it hang. Apparently there is _something_ that makes the Amiga fail its self-test, but that does not impair its normal operation. What could this be? After all the code in the boot-ROM does not try to configure anything on the expansion bus - so I guess the problem must be of "electrical" nature. I read something here in comp.sys.amiga about changing the normal 68000 against a Motorola 68000, supposedly with higher drive capacity. I tried to exchange my Thompson 68000 against a Motorola part, but this actually made the problems worse. Now the hard disk interface couldn't be connected at all, even though the shield was in place and it was alone on the bus. The symptoms were the same as I've described earlier. With a Signetics 68000, my Amiga refused to work at all! It hang in the same way as usual - the 68000 was apparently operative enough to flash the power- LED, but once again the self-test failed. This 68000 couldn't even drive my Amiga alone! Switching back to the Thompson 68000, everything worked again, except hard disk interface and exp. memory at the same time. All these tests were made several times, with consistent results. My setup: Amiga 1000 with internal 256K expansion. It does not have a daughter-board, everything is on the motherboard. Very simple hard disk interface, no auto-config stuff, just one PAL, and two 74LS ICs. The pass-thru traces (you know what I mean even if that is the wrong word) on the board are approximately 3 inch, and they are not buffered in any way. All signals just pass through the interface. XpanderII box with or without a 2MB card. A few questions: Is this normal behaviour for an A1000, or should it be able to drive more than one expansion device, without extra drivers/buffers? Is it considered to be bad design, if you pass the bus through, without extra drivers/buffers when the product specifically is for the A1000? Are there such great differences between 68000's, as my tests seem to indicate? Is poor grounding typical for A1000's, even those without daughterboards? Which signals on the expansion port could be "flakey" enough to make the self-test fail, but still make it possible to run the Amiga as usual after the boot succeded? Is there anything constructive I can do about this, or will I never be able to use a second exapnsion device with my Amiga? Hmmm... A lot of questions - as I don't know much about these things, I would appreciate it _very_ much, if someone helped me out. --------------------------------------------------------------------------- Richard Westman | | 'Hmmm... University of Linkoping | D88.R-WESTMAN@LINUS.LIU.SE | In B, Fenby.' Sweden | | --------------------------------------------------------------------------- -------
D88.R-WESTMAN@LINUS.IDA.LiU.SE (Rickard Westman) (09/28/89)
Ever since I decided to get a hard disk for my Amiga 1000, I've had problems. The first hard disk I tried was returned for several reasons, one of them being that my Amiga had spurious Gurus when the hard disk was connected. Most of the time it worked though, but it was painfully slow (much slower than the manufacturer claimed that it would be). My second attempt was with a GOLEM HD3000. Now really weird things started to happen. It would _not_ work with my expansion memory (an old XpanderII 2 meg box). When I had my expansion memory connected to the pass-thru on the interface, my Amiga even refused to load Kickstart. It did initialize the keyboard, and flashed the power LED, but then it was dead. Specifically, it did not change the screen color from "very dark gray" to "medium dark gray" as it normally does after 1-2 seconds. The strange thing was, that the same thing happened when I removed the memory board from the bus, and just let the box be connected to the interface. This box does *nothing* with the signals from the 86-pin-connector, apart from connecting GND-pins with each other. To be sure, I also tried this with another unpopulated "connector card". The same thing happened with that one. Incidentally, I found out that this would also happen with the interface connected (but not the expansion box) when the big metal shield that normally is above the motherboard, was removed! When I put it back - everything would work. When I removed it - my Amiga was as good as dead again. I tried to put the shield back on, loading Kickstart, and then remove it again. I was surprised to see that everything worked fine. I used the machine for several hours with the shield removed. No problems at all, until I rebooted - then it hang. Apparently there is _something_ that makes the Amiga fail its self-test, but that does not impair its normal operation. What could this be? After all the code in the boot-ROM does not try to configure anything on the expansion bus - so I guess the problem must be of "electrical" nature. I read something here in comp.sys.amiga about changing the normal 68000 against a Motorola 68000, supposedly with higher drive capacity. I tried to exchange my Thompson 68000 against a Motorola part, but this actually made the problems worse. Now the hard disk interface couldn't be connected at all, even though the shield was in place and it was alone on the bus. The symptoms were the same as I've described earlier. With a Signetics 68000, my Amiga refused to work at all! It hang in the same way as usual - the 68000 was apparently operative enough to flash the power- LED, but once again the self-test failed. This 68000 couldn't even drive my Amiga alone! Switching back to the Thompson 68000, everything worked again, except hard disk interface and exp. memory at the same time. All these tests were made several times, with consistent results. My setup: Amiga 1000 with internal 256K expansion. It does not have a daughter-board, everything is on the motherboard. Very simple hard disk interface, no auto-config stuff, just one PAL, and two 74LS ICs. The pass-thru traces (you know what I mean even if that is the wrong word) on the board are approximately 3 inch, and they are not buffered in any way. All signals just pass through the interface. XpanderII box with or without a 2MB card. A few questions: Is this normal behaviour for an A1000, or should it be able to drive more than one expansion device, without extra drivers/buffers? Is it considered to be bad design, if you pass the bus through, without extra drivers/buffers when the product specifically is for the A1000? Are there such great differences between 68000's, as my tests seem to indicate? Is poor grounding typical for A1000's, even those without daughterboards? Which signals on the expansion port could be "flakey" enough to make the self-test fail, but still make it possible to run the Amiga as usual after the boot succeded? Is there anything constructive I can do about this, or will I never be able to use a second exapnsion device with my Amiga? Hmmm... A lot of questions - as I don't know much about these things, I would appreciate it _very_ much, if someone helped me out. --------------------------------------------------------------------------- Richard Westman | | 'Hmmm... University of Linkoping | D88.R-WESTMAN@LINUS.LIU.SE | In B, Fenby.' Sweden | | --------------------------------------------------------------------------- -------
johnl@tw-rnd.SanDiego.NCR.COM (John Lindwall) (09/29/89)
In article <6SJM8NG.B.D88.R-WESTMAN@LINUS> D88.R-WESTMAN@LINUS.IDA.LiU.SE (Rickard Westman) writes: >my Amiga even refused to load Kickstart. It did >initialize the keyboard, and flashed the power LED, but then it was >dead. Specifically, it did not change the screen color from "very dark gray" >to "medium dark gray" as it normally does after 1-2 seconds. > I had this exact same symptom. The solution in my case was to ground the PALS. But this will not help you, because... >Amiga 1000 with internal 256K expansion. It does not have a daughter-board, >everything is on the motherboard. > Wow! This is a new thing to me! What type of hacks were performed to allow an A1000 with NO daughterboard? >[Much stuff deleted] > >Is poor grounding typical for A1000's, even those without daughterboards? > A1000's are famous for flaking out after more then one expansion device is connected. Typical solutions include grounding the PALS or replacing the PALS. In your case (No PALS, I guess) I don't know what to suggest. Good luck to you. -- ---------------------------------------------------------------------- John Lindwall johnl@tw-rnd.SanDiego.NCR.COM "Above opinions are my own, not my employer's" Today is the last day of your life so far.
mlelstv@immd4.informatik.uni-erlangen.de (Michael van Elst ) (10/04/89)
johnl@tw-rnd.SanDiego.NCR.COM (John Lindwall) writes: >In article <6SJM8NG.B.D88.R-WESTMAN@LINUS> D88.R-WESTMAN@LINUS.IDA.LiU.SE (Rickard Westman) writes: >>Amiga 1000 with internal 256K expansion. It does not have a daughter-board, >>everything is on the motherboard. >Wow! This is a new thing to me! What type of hacks were performed to allow an >A1000 with NO daughterboard? >>[Much stuff deleted] >>Is poor grounding typical for A1000's, even those without daughterboards? >A1000's are famous for flaking out after more then one expansion device is >connected. Typical solutions include grounding the PALS or replacing the PALS. >In your case (No PALS, I guess) I don't know what to suggest. Good luck to >you. These A1000 (without daughterboards) came some time after they introduced the PAL versions of the A1000. A had some bad and some good experiences with it. The good is that all devices at the expansion connector work better since the four PALs are now on the motherboard. Nevertheless, since the 256k Kickstart RAM is on the motherboard too, there is more noise on data/address lines as well as on the power supply. I got some memory internal memory cards (sitting in the 68000 socket) working when adding additional vcc and gnd lines between the power supply connector and the 68000 socket. Michael van Elst E-mail: UUCP: ...uunet!unido!fauern!immd4!mlelstv