RAID IIci

[olePigeon]

I've started a new project. This one looks very doable. In the HDD area in the IIci, there's quite a bit of room, but not quite enough room for two HDDs.



However, when I looked at the lid of the IIci, there's a 1/8" worth of ribbing on the inside.



I think that if I cut out some of the ribbing on the inside, there should be enough room to put in 2 internal HDDs.



I created a custom SCSI cable for my IIci using my cable kit I bought, spacing the connectors just right to stack two HDDs. I then used FWB RAID ToolKit to create a striped RAID 0 with two 250MB Apple SCSI HDDs.



So far it runs great! Not sure if there's a noticeable speed difference, but it's more of a "because I can" project. Plus, I'm rather proud of my custom rainbow SCSI cable. Tomorrow I'll measure twice, then take my Dremel to the top of the case and cut out the ribs. I'd use a nibbler, but I don't have one. Maybe wire cutters will work; cut it into little pieces, then break them off with pliers.

 

[Trash80toHP_Mini]

Here's what I've done for rib removal:

Use a matte knife/utility knife:

Begin by carving a notch toward every intersection of the ribs at an angle . . .

. . . alternately cut straight down along each intersection . . .

. . . keep at it until you leave just a single square column standing, but it'll break off at the bottom before you really get down that far . . .

. . . and you'll have four V notched ribs that are no longer connected right down to the base of the intersection where the column disappeared . . .

Then all you need to do is score the joint between each side of each rib where it meets the bottom (of the top in your case) . . .

. . . then wiggle each one side to side until fatigue breaks it off flush with the bottom (inside of the top) and you're done.

Then again you could just grind the schiznit outta the thing with your rotary tool . . . I've done both. [}] ]'>

When doing a lid like that, especially the front side with no protrusions. You can make a jig to keep a full size router within limits and supported at just the right height and blow all the ABS out of there in a couple of minutes, making it a bit deeper than the existing surface. [] ]'>

 

[markyb86]

man I love that cabling...

I had to remove the fan shroud from the SE back case earlier, just used wire cutters and angled needle nose pliers but it looks like crap. It worked, just looks nasty. Gonna sand it next time I have it open.

I like what jt is saying to do.

 

[olePigeon]

I don't have anything that fancy. I'll try the knife and see how that goes.

 

[olePigeon]

My rotary has sanding bits and stuff. I'll make sure it's smooth. I also have a few files, those might work better.

I'm going to measure it and hopefully use the ribs as a way to secure the top HDD in place when the lid is connected.

 

[Trash80toHP_Mini]

:lol: Here it is! Quadra 700/7600/G4/800

That was the crazy time hack I got into last time I was home sick, had a cold that turned into bronchitis that time. This one started out as bronchitis . . .

. . . either way it's the friggin' PITs!

Hopefully tomorrow will be my last day "off" < snork! > from work. :-/

 

[Bunsen]

RAID 0 is for speed, not data retention, right? I always get those mixed up.

I somehow doubt you'll see much speed improvement with two drives on the same SCSI channel, but hey, post some before and after benchmarks and prove me wrong!

 

[Anonymous Freak]

Yeah, RAID-0 isn't really 'R'.

Early SCSI-1 hard drives are slow enough that you would see an improvement moving to RAID - but you'd see a bigger improvement by putting a later-model 7200 RPM (or, if you're nuts like me, 10K RPM,) drive on. Put a single drive on that is significantly faster than the bus, and you'll be good.

(Old parallel SCSI, like parallel ATA, is a "shared bus". Its maximum speed is shared among all devices on the cable. So if you put two "fast" hard drives on an old Mac's 5 MB/s SCSI bus, you're wasting it.)

 

[uniserver]

alright now i have to try this with 2 scsi 100mb zip drives might make an interesting sound.

 

[Trash80toHP_Mini]

Judging from what I'm remembering of his toys:

I'm assuming oP's going for a JackHammer/RAID 0, Rocket (DSP DaughterCard?) GreenRadiusPixelRocket configuration. Now that he's got the ATX PSU hacked into the original IIci sheet metal, he feels the need-for-speed and the greed for . . . pushing it hard enough to make it sweat a bit.

That's a lot of iron in that thar IIci . . . have you got another PPC PDS Card up your sleeve or on the way, oP? [] ]'>

 

[olePigeon]

I gave up on the PPC card, it was too much of a hassle. According to FWB, it doesn't play nice with their SCSI card (requires even more tweaks.) Plus, it would require additional changes to my ROM SIMM that I love so much. When I install the PPC card, it overrides everything, so I lose all my Piratey stuff. dougg3 was kind enough to work some magic with my SIMM so that I could keep all my Pirate IIci stuff while still using my Dayster 040 card.

Also, when all said and done, half my stuff either ran slower or didn't see any improvement, as was the case with the early PPC machines.

Unfortunately I can't use my Jackhammer card anyway because I don't have any terminators. I've been scouring the net, but no one makes them anymore. 110 Ohm 10 pin 9 resistor SIP. They're impossible to find.

I've found 1 store that claims to have them in stock, but they have a $50 minimum order amount. I called them and they refused to waiver on it.

 

[Trash80toHP_Mini]

Why do you need Terminators for the JackHammer, now you've got me worried.

How much is a set if it turns out I need them too? If they have any . . .

. . . straight wire Wrap EuroDin 96 (SE/30/IIsi PDS) connectors . . .

. . . I'm working on a list of crystals to order as well . . .

. . . SCSI controller ICs for the Plus . . .

. . . if their prices in general aren't too high , I can add any of the above/whatever else I can think of, to a combined list . . . [] ]'>

 

[olePigeon]

The NuBUS Jackhammer doesn't auto-terminate like the PCI version. There are three spots for 3 terminator resistor packs (they're blue in color.) You have to take them out or put them in depending on the configuration you want for your card.

See here: http://picasaweb.google.com/lh/photo/aFy3q1qWvobqicTFhlp5Ng

3 blue resistors on the left side of the card. You may already have them.

 

[Trash80toHP_Mini]

Yep, I figured I didn't need 'em because it came from a comrade. I take it you only need them in certain configs?

I still need to get a bunch of that other stuff if you want to try to get a $50 order together though.

p.s. I haven't looked yet . . . so if anyone knows where I might find wire wrap EuroDin Connectors to replace the soldertail connectors on my IIsi's PDS, please let me know.

 

[trag]

As others wrote, RAID doesn't help performance much, if at all, on the old Macs. Getting a more modern, faster single hard drive will do more than RAID will.

It's all about bottlenecks. When these machines were new, as slow as the SCSI was, the hard drives were actually slower. The hard drives got faster, but cards like the JackHammer became available, and the hard drives were still slower than the JackHammer.

For example, one of the very first Seagate Barracuda drives was the ST32550, which was a very nifty 7200RPM 2GB drive, back when 7200RPM was considered really, really fast.

However, the very best the ST32550 will deliver is about 6 MB/s. It doesn't matter whether you have the ST32550N or the ST32550W, narrow or wide electronics, the physical platters and heads can only manage 6 MB/s.

In IBM's hard drive specifications this is what is labeled the "media speed". Whatever else you say about IBM, the fact that they actually provided media speed numbers for their hard drives makes them worlds better than the other drive manufacturers in the specification department. It doesn't matter if your electronic interface will deliver 10 MB/s if your media speed is only 4 MB/s.

Anyway, so I put a NuBus Jackhammer in the Power 120 (120 MHz 8100 clone) back in the day. I put two ST32550W drives on it and built a striped array with FWB's RAID Toolkit. I got about 8 or 9 MB/s out of the combined drives. Added a third drive, and performance really didn't increase. Added a fourth drive, performance started decreasing.

So, I kept the two ST32550W (Fast & Wide) drives on the JackHammer, and put an ST32550N (Fast SCSI, Narrow) on the built-in Fast SCSI bus. This got me up to about 10 MB/s. Then I added another ST32550N to the Fast internal bus. No improvement.

Finally, I added an ST32550N to the internal/external SCSI bus. That got me up to 12 MB/s and that was the best I could ever do with ST32550 drives in the fastest NuBus machine available.

So distributing four ST32550 drives across three SCSI busses only bought me a 2X improvement in performance.

And now that years have passed, one could just buy any wide SCSI drive which supports single ended operation from the last ten years, and put it on the JackHammer and probably get better performance than I managed with that RAID.

Plus it will probably be pretty quiet. Those early 7200 RPM drives were **loud**.

 

[Trash80toHP_Mini]

What is your guess for a single U160 or Compliant U320 Drive on the fast/narrow SCSI Cards:

PLI QuickSCSI

ATTO SiliconExpress II

Radius SCSI II DaughterCard

That last is on the 68040 Local Bus/PDS/whatever on the Rocket Board (ISTR them calling it a PDS)

. . . and the JackHammer makes four! ;D

I'd gone about 22 years dreaming of having even one SCSI II Card for the NuBus Architecture. [] ]'>

@ oP: How goes the IIci lid demolition?

 

[olePigeon]

Pretty good. It's looking like I'll have to file it completely down. After removing the ribs, there're still some slightly elevated areas cross hatching the plastic. It's a hair too high. The lid will close, but it bows a little bit. I wanna make it flat. Almost there.

 

[Bunsen]

terminators. I've been scouring the net, but no one makes them anymore. 110 Ohm 10 pin 9 resistor SIP. They're impossible to find.

Tried ebay? Surplus suppliers like Goldmine/Weird Stuff?

Just a thought, any reason why one could not just find 9 bare resistors and jam them in there?

 

[markyb86]

No reason you couldn't buy a naked plug and crimp them into the pins?