steveb@shade.UUCP (Steve Barber) (03/22/89)
This summer it looks like I'll be looking to add another drive to my system, and I've noticed that all the talk about this kind of thing has died down. I have a few questions anyway. (I have been reading news sporadically over the last year or so. I didn't think I missed anything, but it's possible. Sorry if I'm just bringing up old subjects.) 1) Whatever happened to IDT, who was supposed to be making a SCSI board for the 3B1? I haven't heard anything about them or the board lately, and when I sent mail to them a few months ago I got no reply (not even a bounced message). Is there or is there not a SCSI board available now? 2) I also don't remember seeing anything in recent months about the two or three different upgrade kits that were being made that would allow the use of a 2nd drive and drives with higher capacities. Are any of these kits available now, or did they fizzle out? 3) How slow is slow? I.e. if I opt for a slow (say 40ms) 2nd drive onto which I would probably place /usr/spool, whatever source code I keep online, and other misc. stuff that's not speed-critical it shouldn't be too big of a deal. But if I were compiling on that drive, what kind of an impact on speed would I see? Are there any drives bigger than 40 Mb that are ~40ms avg. access time? (I'm looking for as much capacity for as little $$$ as I can without sacrificing too much speed). (I have 3 Mb of memory installed and a lot of disk buffers allocated in 3.51a) 4) What about faster drives? Would I notice a big speed difference if I installed an ~18-~20 second drive as my root drive and moved my present Miniscribe 6085 (28ms) to the 2nd drive position? Is the 3b1 fast enough to make good use of a drive that fast? I do use the system pretty hard. I realize that access time probably isn't that relavant to this question, whereas transfer rate probably would be, but I'm just checking. 5) If the SCSI board does exist, how big of a difference does its faster transfer rate make? 6) Is the Western Digital controller ([12]010) bright enough to be able to handle simultaneous requests for both drives at once? Or can it only handle one request at a time? 7) Has anyone come up with a satisfactory solution to the RF interference problem found when using external drives? What about using shielded round multiconductor cables instead of ribbon cable? 8) Any ideas where I can find a cheap case and power supply for an external drive(s)? Note: my idea of cheap is less than $100! I'd kind of like it to hold both hard disks and maybe a 1.2 or 1.44Mb floppy drive if anyone has figured out how to do that yet. I was thinking that a PC clone tower-style cabinet would look nice and (generally) hold a lot of drives, but those plus a power supply don't seem to be very affordable. Hopefully that's not too many questions for one posting. I am a college student with very limited funds. I'm willing to pay a little extra to do it RIGHT, but finances say I have to make it work the first time! One other quick unrelated question: can someone mail me the old discussion about replacing 3b1 fans with other AC or DC fans? Mine is starting to make lots of strange noises when its cold and just starting up, and I may have to replace it soon. Thanks a bunch! -- --**-Steve Barber----steveb@shade.Ann-Arbor.MI.US----(cmode)-------------------
lenny@icus.islp.ny.us (Lenny Tropiano) (03/23/89)
In article <635@shade.UUCP> steveb@shade.Ann-Arbor.MI.US (Steve Barber) writes: |> ... |>1) Whatever happened to IDT, who was supposed to be making a SCSI board |> for the 3B1? I haven't heard anything about them or the board lately, |> and when I sent mail to them a few months ago I got no reply (not even |> a bounced message). Is there or is there not a SCSI board available now? Well IDT is no longer committed to the UNIX pc world. They gave up on their SCSI board after a very short beta-testing period. It was rumored they had the board developed but gave up on the software since it was becoming increasingly hard to develop when AT&T didn't provide the needed information. I, like others out there, were hoping they would just release the board, specs, etc.. and whatever they had for a nominal fee, and let the net-at-large do the rest of the development. Therefore, they had no need to really support anything, it would be a net-wide project. |>2) I also don't remember seeing anything in recent months about the two |> or three different upgrade kits that were being made that would allow |> the use of a 2nd drive and drives with higher capacities. Are any of |> these kits available now, or did they fizzle out? |> Well the discussions were around for quite some time. There are ways of doing it *NOW*. Gil Kloepfer, Jr. (gil@limbic.UUCP) and I have released the plans to build your own 2nd hard drive expansion board to put on your UNIX pc. It was posted to the net, and I'll repeat the pertinent information here for those who still missed it... For those who still want more information should write either Gil or I, and we'll be happy to help you. John Milton (jbm@uncle) is working on something similar, except the fact he's building the boards for a price. Although he hasn't go into production yet. So if you're electronically inclined, and you'll have no problem building it yourself, the ICUS Upgrade Manual is for you! |Article 3215 of unix-pc.general: |Path: icus!limbic!gil |>From: gil@limbic.UUCP (Gil Kloepfer Jr.) |Newsgroups: unix-pc.general,comp.sys.att |Subject: UNIX-pc Second Hard Drive - Information (lengthy) |Message-ID: <466@limbic.UUCP> |Date: 16 Feb 89 04:22:32 GMT |Organization: ICUS Software Systems, Islip, NY ... | |The ICUS upgrade is a manual, not a kit. It provides the items outlined |below: | | 1. Schematic diagram of the upgrade (extension) board | 2. Full instructions regarding the motherboard | modifications and assembly of the extension board | 3. Theory of operation of the modification | 4. Photographs (aproximately 10) showing the more | difficult portions of the upgrade (sections of the | motherboard where wires were routed, socket installed, | a section where wires are soldered to pads instead of | chips, construction of the extension board) | 5. Diagrams (where the photos fall short) and construction | hints | |For an additional fee of $5, we will also send a disk with the extended |diagnostic on it (this contains commands which allow larger disks to |be formatted [ie. disks with more than 1024 cylinders] and tested, and |it also allows you to partition your disk into multiple smaller partitions). | |To order the upgrade plans, send a check (or money order) for the correct |amount: | | $30 - Hard disk upgrade plans | $35 - Hard disk upgrade plans with diagnostic disk | |...and NET ADDRESS to: | | ICUS Software Systems | Hard disk expansion plans | c/o Lenny Tropiano | P. O. Box 1 | Islip Terrace, NY 11752 | |Make checks payable to Lenny Tropiano or Gil Kloepfer. | |We are requesting that you send us your net address so that we can send |you e-mail when we send out your plans, and so that if any problems are |discovered after we mail your plans, that we can contact you in the |future. |>3) How slow is slow? I.e. if I opt for a slow (say 40ms) 2nd drive onto |> which I would probably place /usr/spool, whatever source code I keep |> online, and other misc. stuff that's not speed-critical it shouldn't |> be too big of a deal. But if I were compiling on that drive, what |> kind of an impact on speed would I see? Are there any drives bigger |> than 40 Mb that are ~40ms avg. access time? (I'm looking for as much |> capacity for as little $$$ as I can without sacrificing too much speed). |> (I have 3 Mb of memory installed and a lot of disk buffers allocated in |> 3.51a) |> The biggest problem with the seek time speed is really how fragmented you let that partition get. The more scattered the blocks are, the more seeking you'll have to do, and hence the longer you'll have to wait. The the blocks are contiguous, then seeking from track to track should be quite fast. Note the ~40ms access time is an average, some track-to-track seeking will be faster, and some will be slower. /usr/spool will get rather fragmented, but the nice part about putting two drives online, you can easily backup the partition and mkfs(1M) [make filesystem] the partition again, and then restoring the data back on, in contiguous block space. If you aren't too concerned on how long it takes you to unbatch news, how long it takes you to read articles ... then ~40ms isn't too bad. If price is a big factor, the ~40ms access time isn't that bad. The old PC7300 10MB and 20MB drives had ~67ms seek time. This is quite slow, especially since you are using that speed for the system drive! |>4) What about faster drives? Would I notice a big speed difference if I |> installed an ~18-~20 second drive as my root drive and moved my present |> Miniscribe 6085 (28ms) to the 2nd drive position? Is the 3b1 fast enough |> to make good use of a drive that fast? I do use the system pretty hard. |> I realize that access time probably isn't that relavant to this question, |> whereas transfer rate probably would be, but I'm just checking. |> Yes, definately. I/O is the biggest hog on this system. UNIX is very disk intensive, and anything to speed up the access of programs would be better! Craig Votava [att!looney!cmv] placed a CDC Swift 3.5" drive in his UNIX pc, not only does it have a 100MB capacity, but it's a ~16ms seek time and half height. He claims this is a *big* improvement! |>6) Is the Western Digital controller ([12]010) bright enough to be able to |> handle simultaneous requests for both drives at once? Or can it only |> handle one request at a time? |> This is a function of the operating system gdisk driver, and only one drive can be selected at a time. The additional hardware for the 2nd drive only multiplexs the data separator between the first and second drive. |>7) Has anyone come up with a satisfactory solution to the RF interference |> problem found when using external drives? What about using shielded |> round multiconductor cables instead of ribbon cable? |> This has been a problem for our upgrade from the beginning. Since the drive is in an external case it's fairly shielded, but the ribbon cables seem to emit a high amount of RF. Round shielded cable would be a thought. Shielded ribbon cable another one. Shielded ribbon cable will be easier to work with since the connectors we use are for ribbon cables, but after looking at the price of those cables, the round cable might be more economically feasible. |>8) Any ideas where I can find a cheap case and power supply for an external |> drive(s)? Note: my idea of cheap is less than $100! I'd kind of like |> it to hold both hard disks and maybe a 1.2 or 1.44Mb floppy drive if |> anyone has figured out how to do that yet. I was thinking that a |> PC clone tower-style cabinet would look nice and (generally) hold a lot |> of drives, but those plus a power supply don't seem to be very affordable. |> Well that's is exactly what we were feeling when we set out to purchase a hard drive case for the upgrades to our machines. With a little research we found out that were are lots of companies that sell these things. We purchased our cases from a company in Washington state. This is the letter of recommendation we got: |From: uunet!happym.wa.com!kent (Kent Forschmiedt) |To: gil@limbic.UUCP |Subject: Re: Need External Hard Disk Cabinet |Newsgroups: unix-pc.general,sci.electronics |In-Reply-To: <418@limbic.UUCP> |Organization: Happy Man Corporation | |In article <418@limbic.UUCP> you write: |>Does anyone out there in net.land know of a company that sells a cabinet |>which would house a full-height hard disk drive AND contains a power supply |[ etc ] | |I purchased a full-height enclosure with a power supply from Almac |Electronics Corp., and have been running a Maxtor 1140 in it for over |a year. It has given me no trouble. | |Almac Electronics Corporation |14360 SE Eastgate Way |Bellevue, WA 98??? |206/643-4991 The model # of the case is the EXTEC-3, it's a full height case that has a power supply that can run one full height or two half height drives. The two we bought at $98 each, have been operating 24 hours/day 7 days/wk for over 2 months without any problems. They remain very cool, with the fan inside. |>One other quick unrelated question: can someone mail me the old discussion |>about replacing 3b1 fans with other AC or DC fans? Mine is starting to make |>lots of strange noises when its cold and just starting up, and I may have |>to replace it soon. |> I did the "AC" fan upgrade to my machine when the fan burned out. After noticing that the DC fan seemed more susceptible to not starting up, or just stopping to operate, I replaced it with an equivalent 3" AC fan from Radio Shack. The AC fan pulls more air through the machine, and therefore keeps it cooler (and unfortunately more dusty). That's been working in my machine for over 1 year now. Hope this answered all your questions .... -Lenny -- Lenny Tropiano ICUS Software Systems [w] +1 (516) 582-5525 lenny@icus.islp.ny.us Telex; 154232428 ICUS [h] +1 (516) 968-8576 {talcott,decuac,boulder,hombre,pacbell,sbcs}!icus!lenny attmail!icus!lenny ICUS Software Systems -- PO Box 1; Islip Terrace, NY 11752
mvadh@cbnews.ATT.COM (andrew.d.hay) (03/23/89)
In article <635@shade.UUCP> steveb@shade.Ann-Arbor.MI.US (Steve Barber) writes:
[]
"6) Is the Western Digital controller ([12]010) bright enough to be able to
" handle simultaneous requests for both drives at once? Or can it only
" handle one request at a time?
yes (seeks, anyway) -- but i don't think the kernel is smart enough to
*issue* overlapping requests (:^<)...
--
Andrew Hay +------------------------------------------------------+
Null Fu-Tze | LEARN HOW TO AVOID RIPOFFS! |
AT&T-BL Ward Hill MA | SEND $5... |
mvuxq.att.com!adh +------------------------------------------------------+scs@vax3.iti.org (Steve Simmons) (03/27/89)
In article <635@shade.UUCP> steveb@shade.Ann-Arbor.MI.US (Steve Barber) writes: >This summer it looks like I'll be looking to add another drive to >my system, and I've noticed that all the talk about this kind of thing >has died down. I have a few questions anyway . . . >3) How slow is slow? I.e. if I opt for a slow (say 40ms) 2nd drive onto > which I would probably place /usr/spool, whatever source code I keep > online, and other misc. stuff that's not speed-critical it shouldn't > be too big of a deal. But if I were compiling on that drive, what > kind of an impact on speed would I see? I had one of the original 20Mb hard drives in lokkur, and upgraded it to a 28ms drive. Amazing improvement in performance when system load was heavy (had 1Mb ram at the time). Even during unloaded conditions, disk-intensive things like expire or compiling had tremendous improvements. >4) What about faster drives? Would I notice a big speed difference if I > installed an ~18-~20 second drive as my root drive and moved my present > Miniscribe 6085 (28ms) to the 2nd drive position? Is the 3b1 fast enough > to make good use of a drive that fast? I do use the system pretty hard. > I realize that access time probably isn't that relavant to this question, > whereas transfer rate probably would be, but I'm just checking. Three disk areas get beat on primarily: swap, /tmp, and /usr/tmp. If you can somehow get all three on the fast drive you'll probably get the best performance. Seek time isn't an issue. Theoretically transfer rate might be, but so far I've seen no-one run into a problem. Steve Simmons Just another midwestern boy scs@vax3.iti.org -- or -- ...!sharkey!itivax!scs "Hey...you *can* get here from here!"