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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: blakespot on July 13, 2013, 03:11:52 PM
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So,
I picked up a pristine Amiga 1000 a few years ago and have played with it pretty lightly until recently -- running slideshows, Dpaint, a few demos and games. Recently, however, I've gotten serious about using and enjoying it (based largely on @neko_no_ko's A1000 project of late).
The system is an NTSC Amiga 1000 with a Microbotics Starboard 2 (2MB FAST) w/ StarDrive SCSI module controlling a 40MB Quantum HD. It has one external 1010 floppy drive.
To get the system more fully fleshed out, I have installed JRComm and established a serial link between my iMac and the A1000 to move files over...
https://vine.co/v/hW0lgu9UTQm
https://vine.co/v/h7Mt2hMzMll
I moved a number of ADFs and other files over fine until, one day, as I detailed in a different thread, the Amiga Guru'ed during a transfer in JRComm, as the disk was being written to, rendering it unable to be validated by AmigaDOS' disk validator. (I can still boot the drive, proceeding after the error message that appears, but cannot write to the volume.)
In order to get recovery tools moved over, I've used JRComm to download to RAM: and write tools out to floppy. In doing this, I still experience the occasional Guru in JRComm...
So I ran across this forum post made by an A1000 user that was under the impression that his Gurus under JRComm were due to the apparent PAL chip problem on A1000's. Some feel that all Amiga 1000's should have the PAL chips wired together, and to the bus, to correct signal issues. It's mentioned here:
http://www.amigahistory.co.uk/a1000faq.html
also
http://www.amiga.org/forums/showthread.php?t=40974
I have not opened this A1000 to determine if it uses a daughterboard. It does support EHB mode. I'd rather not perform this mod if it is not needed, but is this something I should do to avoid these Gurus? I do not see pattern Gurus elsewhere, in using the machine, so far.
Thoughts? Thanks.
Here she is, by the way:
(http://farm6.staticflickr.com/5223/5550452984_1efb083a0c_n.jpg) (http://www.flickr.com/photos/blakespot/5550452984/)
Amiga 1000 (http://www.flickr.com/photos/blakespot/5550452984/) by blakespot (http://www.flickr.com/people/blakespot/), on Flickr
bp
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@ blakespot
I have no idea about using JRCom as I use my Catweasel from my AmigaONE X1000 & good ol 3.5" floppies to transfer files to my A1000; however, I can confirm that if your A1000 is in fact NTSC then it will have a daughterboard.
good luck with trouble shooting your problem & please keep us posted.
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So, is this mod needed? Perhaps I should do it.
Can someone point me to a coherent guide on the process of wiring the daughterboard PAL chips together and to the bus?
Thanks.
bp
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Still trying to decide if this is needed. Did Commodore ever start doing these before the A1000's went out the door? Thanks.
bp
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Honestly if you think you might benefit from this mod then just do it ! Heck if things go wrong I've got a spare NTSC MB here for ya :-)
You can also check out a1k.org as I'm sure I've seen all kinda of Hackery there on our beloved A1000's
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Of all the A1000's I've owned throughout the years, never felt the need (out of necessity) to do the PAL ground upgrade. I did just do it to one of my latest mobo's, but that was only because I was trying to diagnose a potential expansion bus problem with an odd piece of kit. Turned out to be totally unnecessary.
I've heard of people needing a faster PAL or two for certain bus-type upgrades, but again, have never experienced that particular need either.
Hopefully this is clear enough. Rear left-most pins on J, K, L, N get tied together. Can't assume the ground's are always in the same spot though. Notice PAL's P & Q... rear right-most pins...
And then, run your lead of grounded PAL's to the ground of the expansion connector. C140 below the CPU or just above the CPU, are a couple of convenient ground leads.
Oh... and no, have never seen this mod by Commodore (not even units refurbished by them) where the ground mod was performed.
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So, is this mod needed? Perhaps I should do it.
Can someone point me to a coherent guide on the process of wiring the daughterboard PAL chips together and to the bus?
Thanks.
bp
I have the same experience as save 2600. i have A1000's with the ground mods and ones without, i have tied every expansion i could to the side ports and both seem happy(x-surf and trumpcard scsi!). It was always my understanding the grounds affected the expansion bus stuff.
I wouldn't think it would have anything to do with jrcomm. There are other terms out there, why not try them and see if the problem goes away. Maybe Ncomm or Term etc.
you might also make sure you are using a good version of serial.device- there were some replacements that were possibly better/faster. Some versions were known to be buggy.
It also may be wise to reseat the CIA chips if you are inside,remember sockets! sockets! sockets! on these old machines. sometimes a tarnished pin/socket can be the cause.
good luck,
Mech
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So, two Starboard II devices chained together off the A1000 are causing it to reboot to Kickstart screen soon after loading of WB begins. Apparently this is a symptom of the bus noise the A1000 without the grounding mod exhibits.
I can't find a clear drill for doing the grounding mod.
Can someone point me to it? Thanks.
bp
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Our posts on ignore, block or what? Instructions on how to perform this and a pic are to be found at post #6.
...as I said in your other thread, more than likely a power supply issue, but if you want to try the ground mod, have at it!
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Another angle:
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Commodore Canada never did the mod on any A1000's they repaired. Comspec usually did the ground mods on all Services A1000's at least I always did on any units that I Serviced. The mod was a recommendation if any devices were to be chained from the expansion port.
Using the Mod When I had an A10090 I had 2 AX1000 (2MB Memory cards) and the SA1000 (SCSI Controller) connected and had no issues running any applications.
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Right, coincidence being - back in the day, when the power supply was still healthy.
The WCS slow-Fast RAM board is already properly grounded. And at several locations. Which is why the ground mod typically results in little more than a waste of time. Some stripped or lost case screws. Lots of agitation and maybe a borked plastic piece or two. ;)
If Blake's problem is solved by tying some grounds together (that are already tied/linked together, ELSE THE SYSTEM WOULDN'T WORK AT ALL) by adding even more wire to the system, guess I'll be eating my hat. :laughing:
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So you think his issue is a bad PS and NOT the grounding issue? Sorry I will have to disagree on that. Pretty much every A1000 I have used (like 5 so far) would NOT work with piggy backing Zorro expansion devices. I had to do the grounding mod.
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So you think his issue is a bad PS and NOT the grounding issue? Sorry I will have to disagree on that. Pretty much every A1000 I have used (like 5 so far) would NOT work with piggy backing Zorro expansion devices. I had to do the grounding mod.
Been my experience, either way, I've provided written and pictorial examples within this thread on what needs to be done "ground mod" wise. As I said, good luck and we'll see! :)
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Here's a simple test for a weakening A1000 power supply:
How many external floppy drives can you attach before one simply doesn't work and/or is not recognized?
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Here's a simple test for a weakening A1000 power supply:
How many external floppy drives can you attach before one simple doesn't work and/or is not recognized?
don't know but I don't have that grounding mod and I've been using 3 side cars and an external floppy for a while now with no problems but I agree with you that doing that simple mod surely can't hurt
@ shaf
what's up bud :-) say did you ever find that Comspec 2MB board for the A1000 you thought you had when you were moving last summer?
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Run a looping RAM test/diagnostic on your expansion RAM overnight. Bad RAM will of course cause random Guru.
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what's up bud :-) say did you ever find that Comspec 2MB board for the A1000 you thought you had when you were moving last summer?[/QUOTE]
@klx300r
Sorry I never found the Comspec A1000 Boards although I do have most of an A4000. I'm going to repair it replace the Battery and replace the Caps and see if I can get it functioning.
Now living north of Toronto (Richmond Hill)
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Ok - I am going to work this mod tonight. While I am in there, I'll take a look at my internal floppy drive that has a broken read/write sensor (always shows write protected). Any tips on how to remedy that / likely case causing a problem?
Thanks.
bp
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I did the mod. It didn't help.
:-(
What now?
bp
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Well i guess it's either a dip switch setting (did you get a hold of the manual?h or as save2600 has said a few times its probably a power supply issue?
Well at least you've rule out the infamous grounding issue :-)
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I did the mod. It didn't help.
bp
SURPRISE! :laughing:
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... or as save2600 has said a few times its probably a power supply issue?
Thanks for pointing that out. ;)
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OK not sure why nobody else didn't mention it. Why are you wasting your time??!
Replace that POS with a MILSPEC Amiga 2000 professional computer!!! ;)
It has a beefier PS in it too. :)
Haha sorry couldn't resist.