matz@fmeed1.UUCP (Rick Matz) (05/25/89)
[Line eater morsel]
[I am posting this for a friend who does not have net access...Please email
replies to me and I will see that he gets the info, and if there is any
interest, post a summary as well]
-------------------------------------------------------------------------------
A little while ago, I took the plunge and bought a Lucas board. Assembly was
rather straightforward as was the installation. In fact, it powered up right
away and everything worked well. That is, until the hard disk was attached to
the system. I am wondering if the Net can offer any suggestions that might
help me to correct its operation.
Problem: Amiga + Lucas runs wonderfully until hard disk is attached. When HD
is connected, Amiga Gurus and/or erratic booting occurs (no WorkBench).
Suspicion: The Classic Noisy Amiga Bus
System Configuration:
Amiga 1000 (Motherboard notation: Rev A 327049-01 #Y8AA1070247)
(2) 3 1/2 " Floppies (internal and external)
512K RAM (No memory hacks)
Hard Disk
238R Seagate 30 Meg Drive
4070A Adaptec Controller
C Ltd. SCSI
C LTD Pal replacements (2 pal chips into daughterboard)
Grounded pal mod (4 pals on KickStart board hardwired to motherboard)
Running 1.3
Lucas Board Details:
MC68020RC16B (2A70N8624)
MC68881RC16B (2B81G8825)
18 MHz Xtal
68000 socket installed on Lucas board (but no Pixar hack yet)
Hardwired gnd to motherboard (from "Gnd" hole on Lucas board)
Jumper applied between J1 and J2 "square holes"
The Amiga boots with no hard disk attached using a 18 MHz crystal and a U9
value of 74ALS74AN. All operations appear to be correct. When the hard disk
is attached, the Amiga will ask for KickStart, chew on it for a while,
appear to be ready to ask for WorkBench, but instead go nuts with VERY
erratic behavior:
* Sometimes asks for KickStart again
* Sometimes Gurus with numbers like 00000004.00001970 (Software failure)
0000000A.00001970
0000000B.00001970
00000000.00001970
* When it gurus, and asks for a left mouse button to retry, sometimes the
mouse appears to have no effect.
* Sometimes gets almost up to asking for WB, goes to a gray screen, power
light flashes 5-6 times (including a few VERY fast flashes), goes to a
dark screen, goes to the grey screen, cycles power light.....(etc).....
Swapping crystals (16, 18, or 20 MHz) and all the different U9 families does
not seem to help. One question I have is in regards to the grounding mods.
Is there a preferred location for the grounds? I presently have the gnd wire
for the Lucas board and the ground wire for the 4 pals tied together on the
motherboard on the left hand side of the Amiga (as you face it) on a ground
pad near the power supply. This was on the advice of C Ltd. when I replaced
the 2 pals on the daughterboard with their 2 pals.
I am presently at a loss for what to do next. I have heard that there is a bus
termination mod. Is anyone familiar with how to do it?
Any clues, suggestions, or outright fixes would be greatly appreciated.
Thanks,
Ron Buchholz
-------------------------------------------------------------------------------
Please email replies to:
fmsrl7!fmeed1!matz
------------------------------------------------------------------------------Brian_C_McBee@cup.portal.com (06/01/89)
One more LUCAS board problem. Mine works fine with my Supra hard drive, but wont work with my C Ltd. aMEGa board. I've grounded my kickstart daughterboard PALs, grounded the LUCAS ground hole, and built a bus terminator to go on the end of the expansion bus. I terminated the data lines and PRW* LDS* UDS* and AS*. I haven't bought C Ltds PAL replacements, would they do me any good? Would it help to terminate more of the lines on the bus, say, the address lines? I need the RAM expansion 'cause 16-bit compress wont run in 512K (gotta get my news fix every day). BTW: I am running 12MHz parts at 20MHz with a 7474 for U9. This definitely seems to be the best combination. Does Brad read this group?
matz@fmeed1.UUCP (Rick Matz) (06/06/89)
In article <19022@cup.portal.com> Brian_C_McBee@cup.portal.com writes: >One more LUCAS board problem. Mine works fine with my Supra hard >drive, but wont work with my C Ltd. aMEGa board. I've grounded my >kickstart daughterboard PALs, grounded the LUCAS ground hole, and >built a bus terminator to go on the end of the expansion bus. I ^^^^^^^^^^^^ Is there anybody out there who would be willing to describe this here mod to maybe help cure another noisy A1000 bus?? >I haven't >bought C Ltds PAL replacements, would they do me any good? They didn't help my friend's A1000 problems...... > >Does Brad read this group? Are ya out there Brad????
451061%UOTTAWA.BITNET@cornellc.cit.cornell.edu (Valentin Pepelea) (06/14/89)
Rick Matz <matz@fmeed1.uucp> writes in Message-ID: <3429@fmeed1.UUCP> > Is there anybody out there who would be willing to describe > this here mod to maybe help cure another noisy A1000 bus?? Orgininal message describing terminator assembly follows. ------------------------------------------------------------------------ From: Anakin Research <anakin@gpu.utcs.toronto.edu> Newsgroups: comp.sys.amiga Subject: Re: Memory boards and bus noise Message-ID: <1989Jan31.135929.750@gpu.utcs.toronto.edu> Date: 31 Jan 89 18:59:29 GMT Organization: University of Toronto Computing Services I've also had a number of questions in my E-mail on the bus terminator to help with bus noise on the A1000, so here t'is pin 1,2,3,4 Ground pin 5,6 5V+ *Note: Grounds also at 13,25,37,49,61,73,85 Signals to terminate: (20) pin 63 D15 pin 65 D14 pin 67 D13 pin 68 R/*W pin 69 D12 pin 70 *LDS pin 71 D11 pin 72 *UDS pin 74 *AS pin 75 D0 pin 76 D10 pin 77 D1 pin 78 D9 pin 79 D2 pin 80 D8 pin 81 D3 pin 82 D7 pin 83 D4 pin 84 D6 pin 86 D5 The pins on the 86 pin expansion connector are numbered 1 on the top front pin, 2 on the bottom front pin, etc. ie. odd numbers on top, even on the bottom of the connector on the A1000 For the record, here is the network which is connected to each of the 20 signals listed above: 4.7K Signal<----*--------/\/\/\/\/\-------------->5V+ | | 1000 pf. | 1.0K | | | *--------/\/\/\/\/\----| |------->Ground | | *NOTE: must be ceramic Terminator should be put on the last peripheral in the chain. Brad anakin@utcs.gpu.toronto.edu ------------------------------------------------------------------------- Brad Fowles may be cointacted at the address listed above. It tried it, it works. Valentin _________________________________________________________________________ The godess of democracy? "The Name: Valentin Pepelea tyrants may distroy a statue, Phonet: (613) 231-7476 but they cannot kill a god." Bitnet: 451061@Uottawa.bitnet Usenet: Use cunyvm.cuny.edu gate - Confucius Planet: 451061@acadvm1.UOttawa.CA