deraadt@xenlink.UUCP (Theo A. DeRaadt) (10/27/88)
Anyone know what is involved in taking a drive out of an external enclosure and replacing it, probably with something a little bit bigger? It's a full height 5.25" right? Format software will handle it? Any problems to watch out for? <tdr.
bill@bilver.UUCP (Bill Vermillion) (10/31/88)
In article <106@xenlink.UUCP> deraadt@xenlink.UUCP (Theo A. DeRaadt) writes: > >Anyone know what is involved in taking a drive out of an external >enclosure and replacing it, probably with something a little bit >bigger? It's a full height 5.25" right? Format software will handle >it? Any problems to watch out for? > <tdr. The "ideal" drive is the micropolis 1335 - formats to 70 meg. I say "ideal" because that is the drive that Tandy puts in for their 70 meg units. Maximum you can put on is 70 meg. The system can NOT handle any drive larger than 1024 cyl by 8 heads. If you have a Tandy system now, just put the same jumpers in. They send a signal out the cable to turn on a relay to power up the secondary. I don't even have that. I am running non-RS Rodime 203E's. Both external. If you have an internal 15 and and external, you can move both up to 70's and run a maximum of two drives. If you have externals only, that controller can handle up to 4 drives. That about covers it for normal stuff. The interface units for the R/S version of the Bernouli boxex is basically SCSI. Snapp in Cincinnatti (sp?) has been putting up to 8 scsi drives in the 250 meg up range from what I hear. -- Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!rtmvax!bilver!bill : bill@bilver.UUCP
earl@trsvax.UUCP (11/01/88)
/* ---------- "Tandy 6000 Hard drives" ---------- */ Anyone know what is involved in taking a drive out of an external enclosure and replacing it, probably with something a little bit bigger? It's a full height 5.25" right? Format software will handle it? Any problems to watch out for? <tdr. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ There is not really inherent problem to using other hard drives or replacing the existing ones with newer ones. Most anything will likely work. But, do not utilize the latest hi-tech-hi-speed stuff. Many of these hi-tech drives can exceed the design specs for the controller board. Pick drives that more or less mimmick the performance/speed charactersistics of the drive your replacing. You should have no problems then. MOST IMPORTANT ----->> All the Tandy external drives are powered up by 12 volts from the hard disk controller board. This 12 volts is provided in order to energize a relay in the external disk drive which then powers up the hard disk unit. This 12 volts is provided via the DATA ribbon cable on pin 7 (seven). ENSURE that that pin on the replacement drive is not grounded, or you'll get real excited as you smell things going up in clouds of noxious smelling smoke on the hard disk controller board. If you do burn up the resister, it can be replaced using a 33 ohm 1/4watt resister. I like the 33 ohm resister better than the regular one used, as it burns up faster with less damage to PC board runs. You can tell quite readily as to which resister burns out so I don't need to identify it. Older Tandy 12's,16's,16B's, used a Primary Hard Drive plus up to three secondary drives. The primary drive contains the controller board which provides 12 volts for powering up all the other secondary drives. Newer 6000 machines only provide 12 volts for powering up one external secondary drive. I know of a number of people who replaced their internal Tandy 6000 15 meg hard drives with 35 meg, 40 meg, or 70-80 meg units. No one ever stated that they had any trouble at all doing it. Please note though, that if your machine is under lease, warranty, maintenance contract or something that the Radio Shack or Tandy Service Center may not want to work on it, or it'll void your warranties, et cetera. If you expect TANDY to repair your machine in the future, check with your service center as to what the effects will be on future repair work. *********************************************************************** <This information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Corp. Radio Shack/Tandy Corp has no obligation to support the information provided in any way. > Earl W. Bollinger @ <trsvax!earl> "You were in the Clone Wars!", said Luke excitedly. "Yes", replied Obi Wan, "I was a DOS programmer. But that was before the dark times, before OS2."
rmf@media.UUCP (Roger Fujii) (11/02/88)
From article <106@xenlink.UUCP>, by deraadt@xenlink.UUCP (Theo A. DeRaadt): > > Anyone know what is involved in taking a drive out of an external > enclosure and replacing it, probably with something a little bit > bigger? It's a full height 5.25" right? Format software will handle > it? Any problems to watch out for? > <tdr. Not much. You can replace them with any reasonable ST506 drive (I like micropolis). There are a couple of lines you MUST solder into the HD motherboard (the Write Protect), but this is rather straight forward. -- Roger Fujii - Media Cybernetics Phone: (301)495-3305 Internet: fujiirm@cml.rpi.edu (preferred) or fujii@hqda-ai.ARPA UUCP: ..!{mimsy,sundc}!{prometheus,hqda-ai}!media!rmf
mikes@ncoast.UUCP (Mike Squires) (11/07/88)
In article <106@xenlink.UUCP> deraadt@xenlink.UUCP (Theo A. DeRaadt) writes: > >Anyone know what is involved in taking a drive out of an external >enclosure and replacing it, probably with something a little bit >bigger? It's a full height 5.25" right? Format software will handle >it? Any problems to watch out for? It is my understanding that any ST506 drive with 1024 cylinders or less can be used. The faster the seek, the faster the system. I added two CMI 6640's to a 15MB external system with no mods (except that I rejumpered the 15MB to be drive 2 and made one of the 6640's drive 0 - great speed-up). This worked until the 6640's died of old age. The XENIX formatter allows you to input cylinders, heads, and bad tracks; it is apparently possible to play with interleave (I've never done it). Precomp is fixed and it is possible that this might be a problem. I understand that the 70MB is a Micropolis 1325. I currently run a system with three Quantum 2080's (8" SA1000) off an old 8BM controller with no problems. If the primary is changed I know that the write protect stuff has to be faked out (on the 8MB drives that involves taking a line from the output from the Write Protect switch and connecting it to line 5 of the 20-pin data cable. I also have info on the following other hardware hacks: 12MHz 68000 with 1/0 wait states for the 8MHz board; upgrading 256K boards to 1MB; and extending the buss to allow using more boards in a II/16. There was also a recent posting here on using 5 1/4" 1.2MB drives instead of post48-2's. Finally, I have a copy of the KA9Q TCP/IP package that runs SL/IP on a 6000 (from bgun). "sir-alan" is a 16B+/6000 with 3X 2080 running under XENIX 3.2 (3.0 Dev. System). It is a comp.sources.unix archive site. Mike Squires Allegheny College Meadville, PA 16335 814 724 3360 uucp: ..!cwjcc!ncoast!{mikes,peng!sir-alan!mikes} or ..!pitt!sir-alan!mikes BITNET: mikes%sir-alan@pitt.UUCP (VAX) MIKES AT SIR-ALAN!PITT.UUCP (IBM) Internet: sir-alan!mikes@vax.cs.pittsburgh.edu sir-alan: 814 333 6728 1200/2400 anonymous uucp login of "uucp"
mbeast@tls.UUCP (Michael East) (11/08/88)
In article <12876@ncoast.UUCP>, mikes@ncoast.UUCP (Mike Squires) writes: > It is my understanding that any ST506 drive with 1024 cylinders or less can > be used. The faster the seek, the faster the system. I added two CMI 6640's > to a 15MB external system with no mods (except that I rejumpered the 15MB to > be drive 2 and made one of the 6640's drive 0 - great speed-up). This worked > until the 6640's died of old age. The XENIX formatter allows you to input > cylinders, heads, and bad tracks; it is apparently possible to play with > interleave (I've never done it). Precomp is fixed and it is possible that > this might be a problem. I understand that the 70MB is a Micropolis 1325. While we are discussing hard drives on the Tandy, I was wondering if anybody else has played around with the interleave. I did a test last year with 10 different values and had no difference in speed. As near as I can tell the Z80 combined with the controller always reads in an entire track using the controller track read instead of retrieving individual sectors. Anybody know better or can anyone support this theory? I am interested because I have three different drive types on my 16a and if I can squeeze any additional speed out of them... need I say more ;-) Cheers, ----- uunet!attcan!utzoo!tls!mbeast #include <std.disclaimer> Michael B. East (416) 491-6620 ext 508 Senior Technical Analyst (416) 683-5914 (Home) Jonas & Erickson Software, Toronto
uhclem@trsvax.UUCP (11/10/88)
<> R2>While we are discussing hard drives on the Tandy, I was wondering if anybody R2>else has played around with the interleave. I did a test last year with 10 R2>different values and had no difference in speed. As near as I can tell the R2>Z80 combined with the controller always reads in an entire track using the R2>controller track read instead of retrieving individual sectors. Anybody R2>know better or can anyone support this theory? Sorry, the Z80 only reads the requested blocks and the controller can only hold a single block at a time. I suspect your benchmarking method is faulty. Physical disk format interleaves will only improve raw and swap access speed. Non-raw (normal) disk requests are copied through cache buffers in the 68k memory and subsequently the Z80 is handed single block read requests, even if the user read call was for numerous blocks. This is because the cache blocks probably won't be contiguous and when the Z80 gets a multi-block request, it stores/loads the data to/from memory sequentially. (This is standard UNIX/XENIX disk strategy.) To compensate, mkfs allows the fs free-list to be "interleaved" as well. More on that in a second. If you perform a test that causes the swapping of large programs, or more reasonably, read large amounts of data with single calls to the raw device (no naughty writing unless you don't care about the target drive), you will be able to set your physical interleave to optimum for swapping. For normal day-to-day single block disk access (including program loads), the mkfs interleave factors should be adjusted to a number that matches the response time and overhead of the CPU. All mkfs does is sort the free-list it creates so that the blocks of files are spaced far enough apart to compensate for the added overhead of going through the cache buffers. (As the fs is used, the "interleaving" of the fs is gradually lost.) Depending on the version of XENIX 3 you are running, 7 17, 8 17 and 9 17 may have been used. Look at the installation script to confirm which. Note that by default the hard disk interleave is 3:1, so there will be three mkfs interleave numbers that will be close to perfect for you and these are NOT adjacent. I believe they were 9 17, then 14 17, then 3 17 in one version. If the disk interleave is 4:1, there will be four of these points, and so on. Get yourself a big piece of paper and draw out the interleave and you can work it out, or you can do what we did: try all 17 combinations for each physical interleave. You can either use dd from the raw device to null in large quantities or write a program to do a similar activity. Do not use the dread program from the BYTE benchmarks, it randomly accesses blocks to emulate fs activity. Once you settle on the physical format interleave, a secondary drive can be used to determine the mkfs values without having to install over and over again. <My opinion and not that of my company, who recently blew up a bush to break ground for a new building. Honest! The local news teams taped the entire thing but did not show it. They had some footage of a pig being evicted from Houston to show instead.> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...sys1!hal6000!trsvax!uhclem "You've got a nice network here. We wouldn't want something to happen to it."
randolph@Alliant.COM (Verle Randolph) (11/13/88)
In article <12876@ncoast.UUCP> mikes@ncoast.UUCP (Mike Squires) writes: >this might be a problem. I understand that the 70MB is a Micropolis 1325. Just to make sure somebody goes looking for the correct drive, the 70mb Micropolis is the 1335, not 1325. For anyone that is interested, the 44mb is the 1333, and the 130mb is 1355.