papp@remus.rutgers.edu (papp) (04/23/91)
Thanks for all the replys about how to ground the A1000 PALs... I opened up my A1000 and found that they had already been grounded! I strengthened up the solder connections, and put it back together. I still cannot successfully get 2 devices to work on my 1000 bus. I am using an Expansion Technologies Escort 2 with 2 megs of memory, and a hard drive controller. (I have both a CLtd. controller and the Exp. Tech SOTS controller.) No pair of these devices works. The computer makes it through kickstart, and sometime even makes it to the workbech. However, the machine crashes almost immediately after this. (Sometimes right away, sometime a minute or so later) I have heard that there are 2 different manufacturers of the PAL chips, and that one of them is more reliable than the other. I believe mine are TI chips. Would it help my situation if I replaced these chips with this other manufacturer's chips? Are they even available anywhere? I didn't remove the A1000 daughter board, so I'm not sure of this, but it appears that the PALs are soldered directly on to the daughterboard. Can I replace these myself? (i.e. desolder them, and maybe put sockets in and put new PALs in? I am pretty comfortable with soldering irons) Or is there another problem possibly that I am overlooking? One more note... The time taken for the system to crash increased as I continually tested different combinations of devices (heat increase?) All devices work properly by themselves... just not in pairs... And finally, after all crashes, the computer required Kickstart again, not just workbench. Any help on this situation would be greatly appreciated! Thanks, -Al papp@remus.rutgers.edu
jpotter@ucs.adelaide.edu.au (Jonathan Potter) (04/24/91)
In article <Apr.23.10.50.48.1991.9057@remus.rutgers.edu> papp@remus.rutgers.edu (papp) writes: > >Thanks for all the replys about how to ground the A1000 PALs... >I opened up my A1000 and found that they had already been grounded! I >strengthened up the solder connections, and put it back together. <other stuff deleted> >Or is there another problem possibly that I am overlooking? >One more note... The time taken for the system to crash increased as I >continually tested different combinations of devices (heat increase?) >All devices work properly by themselves... just not in pairs... >And finally, after all crashes, the computer required Kickstart again, >not just workbench. Another problem we have found with A1000s is that the 68000s in them are often weak, if not downright faulty. You should check to see if your 68000 is a Motorola one, or made by someone else. If it is, you should replace it. It's probably worth replacing it anyway, as they can be bought for around $10. Jon -- | Jonathan Potter | | Life is like a piece of | | P.O. Box 289 | jpotter@itd.adelaide.edu.au | spinach... | | Goodwood, SA | FidoNet : 3:680/829 | | | Australia 5034 | | Sort of green and wrinkly |
monty@sagpd1 (04/25/91)
In article <Apr.23.10.50.48.1991.9057@remus.rutgers.edu> papp@remus.rutgers.edu (papp) writes: >Would it help my situation if I replaced these chips with this other >manufacturer's chips? Are they even available anywhere? I didn't >remove the A1000 daughter board, so I'm not sure of this, but it >appears that the PALs are soldered directly on to the daughterboard. >Can I replace these myself? (i.e. desolder them, and maybe put sockets >in and put new PALs in? I am pretty comfortable with soldering irons) > Be warned that the daughter board is a 4 layer board! If you are not experinced with desoldering on multilayer boards you could very well destroy it ( and they tain't so easy to find anymore). In any case if you do replace the Pals get some "good" machined type sockets to put in the daughter board. Makes life much better in the future. Another point to remember is the A1000's ground connections to the expansion bus were inadequate and sholud be re-enforced also. They are/were a cause for bus problems also. Lastly, terminate the bus after the last expansion device if possible. This does a lot towards making multiple expansions (and Lucas type addins) work better. Monty Saine
andyg@crash.cts.com (Andy Guevara) (04/27/91)
In article <3077@sirius.ucs.adelaide.edu.au> jpotter@ucs.adelaide.edu.au (Jonathan Potter) writes: >In article <Apr.23.10.50.48.1991.9057@remus.rutgers.edu> papp@remus.rutgers.edu (papp) writes: >> > ><other stuff deleted> > >>Or is there another problem possibly that I am overlooking? >Another problem we have found with A1000s is that the 68000s in them are >often weak, if not downright faulty. You should check to see if your 68000 >is a Motorola one, or made by someone else. If it is, you should replace it. >It's probably worth replacing it anyway, as they can be bought for around $10. > >Jon I also understand that if you use a 68HC000 (this is the CMOS version of the 68000 chip) that a lot of noise problems go away. I haven't tried it myself, but I have it on good authority. Andy "If you are pregnant or nursing, | -= Andy Guevara =- please seek the advice of a doctor | {anywhere}!crash!andyg before using this information." |
rich@documail.UUCP (Rich McCallister) (04/27/91)
In article <Apr.23.10.50.48.1991.9057@remus.rutgers.edu> papp@remus.rutgers.edu (papp) writes: > >I have heard >that there are 2 different manufacturers of the PAL chips, and that >one of them is more reliable than the other. I believe mine are TI >chips. > >Would it help my situation if I replaced these chips with this other >manufacturer's chips? Are they even available anywhere? I didn't >remove the A1000 daughter board, so I'm not sure of this, but it >appears that the PALs are soldered directly on to the daughterboard. >Can I replace these myself? (i.e. desolder them, and maybe put sockets >in and put new PALs in? I am pretty comfortable with soldering irons) I wish I was more comfortable with them - I recently tried to replace the U6 PAL on a 1000 daughter board (to install a KwickStart) and failed. The machine no longer boots. 8-( As for the TI PAL's, I remember reading that the idea that certain PALs worked better than others was put forth by CLtd, but most others seemed to disagree, saying that while the grounding could really make a difference in noise, the differences between the various brands of PALs was in this case almost non-existant. Thus, I would doubt that that is the problem. Then again, I thought the PAL grounding was a likely cause, and have one out of action daughterboard to my credit, so what do I know?