Question for the SCSI gurus: how to downsize a SCSI HD?

[rkauer]

The title says everything: I only found bigger SCSI HDs around (over 2Gb), and I need a humble SCSI hd (with less than 512Mb) for an old SCSI controller.

Is there a way to set the firmware of a Seagate ST34520W (4.3Gb) to accomplish my needs?

Thomas, are you around?

[Jope]

Not really. But you could just lower the cylinder count when you first detect the drive in the partitioning software.

SCSI works with logical block addresses, not real CHS values like ancient IDE, so just make sure the controller software doesn't get to address more than the first 512MB.

[rkauer]

I think that's the whole problem: the controller hangs when it discover the HD. Tested the HD in another two SCSI boards with success.

The controller is the ancient ADD_SCSI for A500/+. AFAIK, it only accepts <512Mb disks, and when the HD answer the controller it don't know what to do or overflow, causing the lock.

So thinking in the problem, I think the only viable solution is "downgrade" a bigger HD (via firmware?) to meet the controller's requirements.

Other solutions: find an old sub-512Mb HD (near impossible or accept to pay ridiculous prices: over US$100 or more!) or use an very old 512Mb IDE HD with an ACARD (expensive).

[Jope]

http://bboah.amiga-resistance.info/c...gi?HARDID=1148 or what?

Perhaps try plugging the drive into something that accepts it and then attempt to create an RDB on it that declares the drive as 512MB. Or is it even RDB compatible?

You're out of luck with downgrading the hd, some IDE drives have capacity limiting jumpers, but unless you're going to create that firmware yourself, it's probably not worth investigating that route.

[rkauer]

Originally Posted by Jope

http://bboah.amiga-resistance.info/c...gi?HARDID=1148 or what?

Perhaps try plugging the drive into something that accepts it and then attempt to create an RDB on it that declares the drive as 512MB. Or is it even RDB compatible?

You're out of luck with downgrading the hd, some IDE drives have capacity limiting jumpers, but unless you're going to create that firmware yourself, it's probably not worth investigating that route.

Nope. It is the AddHard. I think it is RDB compatible, since it is an auto-boot device who works on any 1.3 and up A500.

[TheCorfiot]

@rk

I think WinUAE & your PC SCSI controller is the answer here to detect the drive with WinUAE & then create the RDB to be the required size

When reconnected to your amiga's controller the Modded RDB read in at Bootup should hopefully fool the controller
Best of luck mate

TC

[rkauer]

So I need to install UAE in the peecee. Damn! I always hope to not run an Amiga outside the Amigas I own.

Not degrading the Toni's work (who I think is superb!), but I never want to emulate an Amiga again. Call me anal-retentive (OT: this word needs hyphen?), but I always got the sensation the emulation speed runs circles around my real HW, who is a thing who depresses me.

[Toni Wilen]

I also have some old A500 SCSI HD controller that refuses to detect any drives that are "too big" (freezes). With or without RDB.

I guess ACard + IDE or CF card is the only solution. (or getting better HD controller..)

[rkauer]

Wifie will kill amigan...

An acard is one of mine consumer's dream. In truth, a bunch of Acards is that dream.

[rkauer]

Another guy in that other forum gave me the solution.

There is an utility who can make almost everything with a SCSI device (HD, CD, pick one).

It is called scu!

OK, time for hacking one HD!

[TheCorfiot]

Nice one rk

Let us know how you get on, sounds like a very useful Utility

TC

[rkauer]

Very useful, if I manage to identify the SCSI bus name.

peecees are not my friend... ARGH!

[TheCorfiot]

rk

If the utility is PC based then after the drive is connected open Windows Disk management & that should give you all the details you need, ie bus ID number etc..

Unfortunatley I don't have any working SCSI HD 512MB or less otherwise you would be welcome to it.
I have an apple one (170MB) but I think the firmware is special for Macs as I could never get my GVP HD or HC controllers to identify or work with it.

Keep at it mate

TC

[rkauer]

Nope, Xp don't give the information (maybe it hold it just for itself? Damn M$!)...

[thomas]

the controller hangs when it discover the HD. Tested the HD in another two SCSI boards with success.

The controller is the ancient ADD_SCSI for A500/+.

Does the controller have its own power supply ? If not then I'd suppose that it's not the size of the disk which makes the computer hang but the additional power it needs. Try to power the HDD from a seperate supply.

[Toni Wilen]

Originally Posted by thomas

Does the controller have its own power supply ? If not then I'd suppose that it's not the size of the disk which makes the computer hang but the additional power it needs. Try to power the HDD from a seperate supply.

Same drive worked on Supradrive 500XP with latest ROM (didn't work with old ROM) My Amiga power supply is old 200w AT PC power supply which should have more than enough power-

Anyway, I don't care about it anymore because Supradrive is much better

[rkauer]

I've powered the HD directly from the PSU (perfect voltage levels) to eliminate this as a probably cause of malfunction the very first time I don't succeed.

I hope I find a way to re-write the SCSI HD "firmware" to minimize it into an acceptable size.

[OddbOd]

Originally Posted by rkauer

Very useful, if I manage to identify the SCSI bus name.

Can't you use bus scanning to find the right device? Looking at the docs scu scan edt should do the trick.

[rkauer]

Nope, the program complains the lack of a parameter or parameter invalid.

I've tried with another program (win98-based) and it found the drive, tested it but lack a lot of features, like HPA (diminish the apparently size of the HD in the "firmware").

I think I'll another combination soon: boot from that program, quit and then run scu again (maybe the program don't mount the SCSI at boot - DOS boot).