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Post by bullis1 on Jun 11, 2008 11:11:36 GMT -5
50/68 pin SCSI adapters will work with many hard drives. Alot of 68-pin drives have jumpers to allow them to work on 50-pin cables with the use of an adapter. I've done it myself in a Pentium PC with a controller card, and in an Amiga3000. I hear some SCSI HDs will even detect this automatically (but I haven't personally experienced this).
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Post by Tom Maneiro on Jun 11, 2008 18:16:09 GMT -5
Well, there are some hope in this issue: www.hitachigst.com/tech/techlib.nsf/products/Ultrastar_9LPAfter checking the datasheet of my DGHS's, i think that they MAY work in my AHA-1542: they're wide-SCSI (and single-ended, not LVD), but my card is narrow-SCSI. Check this out: www.hitachigst.com/hdd/support/dghs/dghsjum.htmThere is a jumper called "Disable Wide Negotiation", and quoting IBM/Hitachi: It means that i may use my drive with my card, however, some caveats may apply: - www.storagereview.com/guide/cablesAdapters.html =>it points that not all adapters do the same thing. Pick the wrong adapter, and you will be wasting your money. - According to Adaptec, the AHA-1542 supports drives up to 8GB. I'm not sure if this limit is on the card BIOS or in the drivers. If it's on the BIOS, fine, because i'm not using it ;D But if it's on the drivers... it's still OK, because i can still use up to 8 giga! - IBM didn't tested this drive with AHA-1542 - so compatibilty is unknown... I will try to get that adaptor! 504MB sucks! EDIT: www.transintl.com/technotes/sca/c_68to50nonlvd.htm => seems to be a good one. At $19, it's still cheap, but if you want a terminator, you must add $10 more. Damn you, $c$I! |
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Post by paulpsomiadis on Jun 15, 2008 16:59:27 GMT -5
Yeah, but I bet "SkyNet" would charge more for THEIR type of Terminators...  LOL! ;D |
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Post by GiGaBiTe on Jun 16, 2008 4:33:23 GMT -5
You generally don't need a terminator on the SCSI bus unless none of the devices on the bus (including the host controller) can terminate the bus themselves.
the only times I've seen the necessity for bus terminators was on extremely high-end SCSI controllers and drives, and even then it was more for redundancy than necessity.
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Post by bullis1 on Jun 17, 2008 10:17:02 GMT -5
You generally don't need a terminator on the SCSI bus unless none of the devices on the bus (including the host controller) can terminate the bus themselves. the only times I've seen the necessity for bus terminators was on extremely high-end SCSI controllers and drives, and even then it was more for redundancy than necessity. Have you ever used older SCSI devices then? External SCSI chains could be terminator nightmares! It was especially annoying that some devices only worked properly at the end of the chain, but weren't able to self-terminate. You'd have to track down the correct terminator and pay good money for what was essentially a hunk of plastic and some simple electronics. Grrr... Lately I've been reliving this crap because I added a SCSI card to my Atari ST computer. Modern SCSI is nice because it seems that as long as you just have a bunch of hard-drives on the chain, and no optical drives, you don't even need to terminate. I'm sure this depends on your specific controller/drive brand though. Either way, it's a lot nicer in PC world than it was in Atari/Amiga/Mac land as far as SCSI goes. Old PC SCSI cards probably have some some dependency on termination too. There's just so many variations to consider, unlike IDE! |
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Post by paulpsomiadis on Jun 17, 2008 20:16:32 GMT -5
Hallo bullis1 - you should register and join the forum proper.  (makes a change from all the spambots that use the "guest" ID for spamming...)  Anyhow, you are indeed correct!  I have noticed that the optical drives in my 486/387 Hybrid machine will only work in a certain order...  Even if you set their SCSI IDs differently and make sure they're correctly terminated. They ONLY work (and more to the point FIT inside my case) in this order... WD SCSI 3GB HDD = ID 0 Yamaha SCSI CDRW = ID 2 Pioneer SCSI DVDROM = ID 4 SCSI can be a pain sometimes!  But I still prefer it to IDE... ;D (If I had a suitcase of cash, I'd buy some SAS drives for my gaming rig [Serial Attached SCSI])  They use fiber cable connections for a MIND NUMBING speed of 4GB/s!!! Holy underpants Batman!   |
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Post by Tom Maneiro on Jun 18, 2008 10:01:49 GMT -5
My old Quantum FireCrap TM only needed one jumper - Terminator Enable. It worked fine at the default SCSI ID 0 (and i only had one of those smallish micro-jumpers, so it had to work at the first try!).
And about SAS/15K drives: Their only good points are
- LOW latency (only a SSD is faster in this point, with zero latency)
- reliability (long warranties, emergency tech-support, and a good chunk of the drive price tag)
Data density is pretty low (although this is becoming a non-issue with the perpendicular recording thing, and we now have 450Gig 15K drives), and they suck watts like Hummers suck gas. And the noise... well, this is also becoming a non-issue with those newer 2.5" drives.
I would not hurry now for a 15K SAS drive. Instead, i would wait a few years, and THEN, pick a couple of 2Tera, 20000RPM drives ;D
(BTW: Why there are no 20K drives?)
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Post by bullis1 on Jun 18, 2008 10:05:09 GMT -5
Hallo bullis1 - you should register and join the forum proper. ... They use fiber cable connections for a MIND NUMBING speed of 4GB/s!!! Okay, I did. I've been posting here sporadically for a few years so it was about time. These fiber optic connections must only be able to transfer at that speed theoretically right? I don't think a drive could spin that fast (or maybe I'm behind the times). I prefer my parallel-port drives. Speeds of almost 5 megabytes per minute And no chaining, only switching between one at a time. I've been following this thread since the beginning. I don't have a 386 computer, but my PC at home is a Pentium 150mhz (64MB RAM, 4MB Rage II+ video, plus other shit and no MMX of course!) so some stuff in this thread still applies. Thanks to constant optimizations I haven't had to buy a new PC since 1996 I'm always looking for better ways to add drive space though, not including compression. Also, I've been using Arachne web browser for years and I highly recommend! It doesn't like some stuff like yahoo mail and some forum software though. For that stuff I have to put Planetweb in my dreamcast. |
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Post by paulpsomiadis on Jun 18, 2008 18:29:01 GMT -5
They are currently in proto to be released either later this year or early next year. My DC sits PROUDLY next to my X360 in my mediacentre - and so it SHALL remain! ;D (incidentally my DC is a USA version with clear Cadillac pink case - groovy!) |
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Post by Tom Maneiro on Jun 18, 2008 19:53:28 GMT -5
They are currently in proto to be released either later this year or early next year. Oh, yes... another Western Digital "exclusive"... Will it have coin-sized platters, and beer/soda can-sized spindle motors? Hopefully not, but the platters will be pretty small. |
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Post by GiGaBiTe on Jun 19, 2008 22:45:02 GMT -5
Have you ever used older SCSI devices then? External SCSI chains could be terminator nightmares! I have oodles of old SCSI drives and controllers. I really never had that many problems with them compared to IDE. Termination was seldom an issue with my stuff and never gave me many problems. The only downside to older SCSI stuff is that it's much slower than IDE. PIO 1 is 16.67 MB/s while SCSI-1 is 5-10 MB/s. 68 pin SCSI can compete with DMA IDE and SATA though. |
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Post by Tom Maneiro on Jun 21, 2008 11:48:02 GMT -5
Old IDE uses PIO, and PIO uses CPU... I'm not sure how much CPU do use PIO-1, but on a 386 there is some overhead of doing it (i have never measured it, but doing tasks, like copying files from a CD-ROM, can reach snail speeds). Old SCSI can be slower, but i think, that if it uses DMA, it would be better than PIO.
I'm not sure if my host adapter does DMA, though... If it does, fine; if not, well, at least i can use HUGE drives there ;D
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Post by GiGaBiTe on Jul 1, 2008 4:27:35 GMT -5
Old IDE uses PIO, and PIO uses CPU... I'm not sure how much CPU do use PIO-1, but on a 386 there is some overhead of doing it (i have never measured it, but doing tasks, like copying files from a CD-ROM, can reach snail speeds). Old SCSI can be slower, but i think, that if it uses DMA, it would be better than PIO. I'm not sure if my host adapter does DMA, though... If it does, fine; if not, well, at least i can use HUGE drives there ;D Yeah, SCSI doesn't use nearly as much CPU time for setting up the data transfers and DMA helps out too. I guess if you had to do heavy duty disk access all the time and wanted any sort of application speed, you would want SCSI. |
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Post by bullis1 on Jul 3, 2008 10:37:38 GMT -5
I have a question. Does anyone know if there was a battery-backed (or otherwise reboot-proof) RAM drive available for old PCs? Even if it was a very small capacity. I have used similar devices/programs on other platforms but I haven't seen it on PC. There is a very recent piece of hardware that uses standard RAM as a drive through an adapter card of some sort, but that's new and not what I'm looking for really.
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Post by paulpsomiadis on Jul 3, 2008 11:33:48 GMT -5
I once saw a SCSI to CF adaptor that could be used with old ISA SCSI cards... But it was one of those "only happens once ever" eBay items! ...wish I had picked it up! |
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