A1200 stability

[Jumping Anaconda]

I gave up trying to repair my VGA connector and decided to use the RF output to connect to a normal TV. CRTs are so much better these days compare to when I had my original Phillips RGB monitor.

However, I am having some stability problems.

All I want to do is to review my collection of floppies and archive some of it with ADFBlitzer, so I can take the drive out and then use the data on the PC via WinUAE.

This is the spec:

A1200
Blizzard IV 68RC030 at 50mhz (no FPU) + 4 meg Simm
3.5 inch Hard disk
4.3 amp A500 power supply

The Workbench installation is a version of Amithlon, or whatever it is called.

I had fitted a Conner 242 meg 3.5" drive about ten years ago and had it runnign fairly stable. Although it booted when I tried this time, the floppy drive was not working at the same time. After a while the HD it started to give read errors (requestors saying things along the line of 'Cannot read block xxxxxxx'), so I thought it might have failed and as a result was drawing too much power across the machine trying to spin the drive up. However, the drive read fine in my PC under UAE. So I copied everything off the disc and copied to a 1 gig 3.5" drive through WinUAE and put it back into the Amiga. I also tried to shield this drive a bit more by putting some cardboard between the drive and the metal shielding.

The new drive ran ok for a few minutes, but then it started giving read errors. I reset the machine and I started getting instability on when it tried to boot. I switched it off for a a couple of minutes, and when I switched it back on, I was getting Gurus before it even got to where you would expect either boot or a insert floppy animation.

Does anybody have any idea what the problem could be? I am suspecting it could be a power issue. If I had a 2.5 around I would switch back down. I was considering removign the accelerater, but I would guess that the hard disk draws a lot more than that anyway. Also ideally at some point I would like to test the accelerator with the hard disk in place. So I was considering a bit of a kludge, trying to power the drive (and maybe the floppy) from the power line of an external caddy, running the cable through the back plate. I'm not sure if the caddy I have will supply power when no drive is attached to it, so I may have to modify this to using spare power sockets from a running Intel case. Neither solution is idea, but does anybody think it might be something other than power issues causing this problem?

Any guidance gratefully received.

 

[Lechuck]

Hello there friend,I have also come across with this problem.

Firstly , I thought that the problem was with hard disks so I tried several both 2,5 inch and 3,5 inch.But I kept having those random read errors , some in the beginning , others after 1 week , after a reboot or something , with different a1200 motherboard revisions and configurations(desktop with plain 44-pin ide cable and tower with 4-eide adapter).My tower has a 300w psu so this I think the problems are not caused by lack of power.

On the contrary , I have noticed very minor issues with cf adapters & cards so I prefer them.

I do not know what is causing the instability of the 1200 when using hard disks, maybe architecture issue or something else but it is really annoying especially when you get read errors in the boot partition and you have to install everything again.

 

[r0jaws]

It might seem a little obvious, but have you checked the seating of your ROMs?

Also, have you tried a different IDE cable? Have you checked the output of the PSU? Is it giving good clean power?

 

[Jumping Anaconda]

Thanks for your reply Dkaram. Just before I went to bed last night i noticed that there was a slight fray on the orange disk light wire, so I will insulate this before I start testing today. If it is passing a tiny current across the shielding I guess it could because trouble.

When the machine was in regular use I had some trouble with stability when I was using this machine with my MagnamRAM8 expansion, 2.5 inch drive and the original 2.5 amp A1200 supply. However, these problems were largely resolved after I got the A500 4.3 amp supply.

I remember that when I first got the MagnamRAM8, I could barely get the thing to work at all. I soon realised that the shielding, which I had already bent somewhat to give room to get the card in, was still in contact with the card when the trapdoor was shut. I ended up bending the part of the shielding that pointlessly dips down into the slot back even further to ensure it was not causing trouble.

That shielding has to be one of the worst pieces of electronics design I have ever seen. It screams of Commodore cost saving. It is completely unsuitable for the application. I would not be suprised if it was designed for a different version of the case and motherboard, with a different material, and probably for a third world county's radio regulations, because is sure filters very little of what comes out of the machine.

If they had used a decent material for the shielding, and they had shaped it slightly differenty, it would have been easy to fit a 3.5 inch HD in there and maybe even a small fan which could have been run as a slow and quiet speed to keep things nice and cool. The cost saving of using 3.5 inch drives would have more than covered the cost of the shielding. But of course, as Commodore priced everything based on the lowest common denominator, thatwould never happen - i.e. vanilla A1200 with no hard disk, why bother with the expense of shielding that those users might never need?

I am not a designer, but if I was putting the A1200 together, I would have stuck a double caddy for a 3.5 inch drive and a CD Rom on the left side of the case. You could fit the HD in the first caddy and CD drive in the second. The HD would get plunged into the midddle of the machine where its caddy would meet with its ide connectors, and the optional CD Rom would be accessible from the left side. If the profile of the shielding was lowered there would have been more than enough room to do that. That way retailers would have had the opportunity to easily package the machine with whatever were the more competitive drive configurations at the time. It is crazy that retailers were having to open up these machines and break the warranty seals just to insert a hard disk!

And it is so frustrating that CD on the A1200 was considered "impossible" unless using the trapdoor, thus negating further serious expansion - I remember Amiga Format barking that you can not access the right signals from the PCMCIA slot to do it, prior to the Squirrel appearing and proving that wrong. But there was a perfectly good, albeit half baked ide connector sitting in the machine that should have been able to do the job, but due to yet another cost reduction done to save a few pence, for most machiens it couldn't.

Anyway, I have meandered of my original point somewhat, but still no stability

---------- Post added at 08:34 ---------- Previous post was at 08:15 ----------

It might seem a little obvious, but have you checked the seating of your ROMs?

Also, have you tried a different IDE cable? Have you checked the output of the PSU? Is it giving good clean power?

Thank you for your suggestions R0jaws. The ROMs seemed to be seated ok, but the Blizzard is set to MapROM with blizkick at boot anyway, so if there was a problem reading them, I would guess that would only have a chance to become evident at boot?

I do not have an alternate IDE cable, only the 2.5 to 3.5 adapter my friend installed for me when we put the original 3.5 inch HD in. I will try and check it is pushed home correctly. Is the connector on motherboard a standard 2.5 inch connector? I might be able to pick up a replacement cable from Maplins or somewhere like that.

How would I test the output of the PSU? I would expect that the power going into the PSU would be cleaner than in most households as the room I tested it in has its own dedicated box. Having said that there is no UPS or anythign like that in line to ensure a clean supply.

Thanks again for the guidance.

 

[jvdbossc]

hello

hello

In a previous post it was comfirmed that you can use second psu (to provide the power to the hd)

maybe have a look at:

www.amigamaniac.com

Also it was stated that the power lines (on the motherboard) are not up to the task to drive a big hard drive. So having an atx to A1200 power cable and using the molex on the psu to drive the hard disk could rule out finally your problems.

I do not agree with your design comments, the A1200 has a laptop hard drive for a reason - nice and quit, not power hungry, light weight ed..

If you are in need of a laptop hd, I have spares, but might be better for you to pick it up more locally.

Much luck!

 

[r0jaws]

I would still try re-seating the ROMs if at all possible, they do eventually work loose over time and a removal and re-insertion can settle down some problems.

The ide port on the mobo is indeed a standard 44 pin affair. You can pick up cheap 44 pin IDE to Compact Flash adapters all over the place and the main forums are littered with people using 4Gb CF cards instead of hard drives. I do this myself and it is a much easier alternative. They are also quiet and power efficient as well.

You need a multi-meter to test your PSU really, but if you're not sure I would recommend you ask a friend who is familiar with what they are doing to check that the right voltages are coming through.
You should get a steady +5v, +12v, -12v, and a ground.

 

[Jumping Anaconda]

Thanks for the further guidance r0jaws and jvdbossc. My basic purpose for putting the machine back together is to test it and the peripherals I have, and to transfer any data I have on Amiga formatted disks. So today I tried to take out all the variables and removed the accelerator, and successfully managed to get the hard disk powered from a connector from an adjacent P4 case.

I changed the startup sequence so it just loaded Workbench and fired up adfblitzer. I'd get about 6 disks transferred then find it stuck up a suspend requester (I think the error was 0000020) and I'd reset it and start again. This could be an ADFBlitzer problem. I have noticed that it does not release the memory it uses when it has transferred a disk.

This setup should work enough to achieve the immediate pressing task. Thanks again for your help.

 

[rkauer]

Another major cause of random GURUS and malfunctioning is when the motherboard capacitors start to leak.

Replacing them will cure most of the problems caused by devices who "eats" much power. BTW: the A1200 was not designed to use a 3.5" HD because it require much more power than the 2.5" counterpart. Using CF cards instead will ease the power consumption, too.

 

[RedDaemonFox]

Use a CF-2.5 IDE drive, much more stable and such. If I had the better cF adaptor (the one that rests the CF on a PCB) I'd ditch the shielding altogether.