Installing a Miniscribe 3650 Hard Drive, Using a Perstor 180 Controller (or another RLL Controller) * ------- by Jim Russ, Orlando, Florida, (305) 851-0705 -------* OK, guys (and gals), listen up 'real' good... Here's a way to get AT LEAST 77.9 Megabytes from a Miniscribe 3650 Hard Drive if you use it in conjunction with a Perstor 180 Controller Board (available from Richard Driggers, SYSOP of the Sparta BBS, voice 1-201-729-9409). Actually, these half-height drives are sold as 40-Megabyte units, but they take to RLL formatting and to the Perstor 180 board like a duck takes to water. At only $314 each, I ordered two... the total was $628 for the drives and another $8 for shipping, with the total outlay running $636! Sold my two Seagate hard drives, recovering $500 of this cost, so my final out-of-pocket expense was $136, and I now have over 155 Megabytes of writeable hard disk space. (My supplier's address is on page 3.) With this procedure, a Miniscribe 3650, and an Adaptec 2070A RLL con- troller you can get nearly 63 megs of writeable space; when used with a Western Digital or an OMTI RLL controller, you can format about 65.5 Megs, but the Perstor 180 will obtain 78 Megabytes PLUS a file transfer rate of about 180 KB/Second! (Although I have yet to try it, a Perstor 200 board should be able to format the Miniscribe 3650 out to 85.6 Megabytes! If I get my hands on one, I'll try it out...hint, hint). And all this WITHOUT the use of the Perstor compression and WITHOUT the need to use the ONTRACK Disk Manager programs *. Heck, you can get well over 100 Megabytes on a single Miniscribe Half-height 3650 Drive if you opt to run the Perstor Compression Software! (I tried this once, and ended up with a total of 126+ Megs, but reverted to the procedure described here as most of my files are already archived, and the tricky compres- sion procedure gains me very little in its process.) * You'll need DOS 3.2 or higher, otherwise you need ONTRACK Disk Manager! First, open your computer (mine is an AT&T PC 6300). Replace your existing controller with the Perstor 180. Next, install the Miniscribe 3650 in place of your existing hard drive (Seagate??). The striped lead on both the 34-conductor and the 20-conductor ribbon cables must be toward the REAR of the computer when connected to the Perstor card. Although Miniscribe touts their 3650 as having 809 cylinders, I have discovered that this drive can actually be formatted out to 820 cylinders, therefore Table 4, describing jumper settings for JMP6, as listed on page 6 of the Perstor owners' manual shows the proper set- settings. Just jumper (short) pins 3-4, 7-8, 13-14, and 15-16. This will set you up not only for Physical Drive 0 (jumper 7-8), but for another, later Physical Drive 1 (jumper 3-4). Next, boot "Vanilla," using MS-DOS 3.2 or later (PC-DOS 3.2 or later probably works, too...); you should also have FDISK.COM, FORMAT.COM, CORETEST.EXE ( V E R Y important!), and Perstor's PS2FMT.COM available for use after you have booted; for OTHER controllers, have DEBUG.COM for the low-level format, using the addresses described in the literature which comes with your RLL controller. (For your information, the address to be used with an Adaptec 2070A RLL Controller is c800:CCC, for the Western Digital RLL Controller, it is c800:5, and for the OMTI 5527A Controller, it is c800:6. After executing DEBUG, you will receive a - prompt; you just type in g=(address) and, generally, just follow the prompts which are generated by the BIOS chip internal to your own particular controller.) As the interleave factor is important if you wish to optimize the controller-computer interface for optimum (fastest) file transfer rate, you will want to follow Richard Driggers' methodology for determining the best interleave factor; his method is described below: 1. Boot "Vanilla." 2. Insert the diskette containing the PS2FMT program into the A: drive. Type PS2FMT, then press . 3. As the default for your first run should be an interleave factor of "4" just select that default on your first try, and start the low-level format. 4. After about 1 1/2 minutes, place your boot diskette into drive A: and press your reset button. Run CORETEST now (never mind that the drive has not been high-level formatted; CORETEST does not care, and will test it anyway). Record the results. 5. REBOOT. 6. THIS time, select "5" for the interleave factor. Again, run PS2FMT for 1 1/2 minutes, then reboot and run CORETEST, again recording the results (probably will be higher). 7. Keep cycling through this procedure until the transfer rate in KB/Seconds DROPS. Then, back up to the LAST interleave factor you selected and low-level the ENTIRE disk with that interleave. (In my case, "5" was the optimum... ) 8. If the format program encounters any bad sectors during the low-level format, it will display the track and head numbers. You should carefully monitor this entire procedure, and when prompted to do so enter these data so those tracks will be marked as bad... 9. Next, figure out how large you want each of your partitions to be... This can be calculated very simply with the fol- lowing formula: GENERIC: Cylinders X Heads X Sectors/Cylinder X 512 bytes = Writeable Bytes Perstor 180 with Miniscribe 3650: 820 X 6 X 31 X 512 bytes = * 78,090,240 Bytes * As this is too large to be recognized as a single drive (DOS limits you to 32 Megabytes per partition), you must make your partitions no larger than 351 cylinders each (on the Miniscribe 3650)... In my case, I elected to use 273 cylinders each for two partitions plus another partition for the remainder. The first partition became my DOS partition (drive C), and the remaining two became DOS DATA partitions (drives D & E). IF you add a second Miniscribe 3650, ALL of partitions must be DOS DATA partitions! 10. Run FDISK, then partition the drive in the way you have selected. Be SURE to make partition #1 (DOS) Active before backing out of the FDISK program. -2- 11. REBOOT. 12. At the A: prompt, type FORMAT C: /S and press , then answer Y when the warning that all data on the hard drive will be lost. Let the format proceed. 13. Next, type FORMAT D: and press , again answering Y at the warning. 14. Type FORMAT E: and press , again answering Y at the warning. (15. If you created four [maximum under DOS 3.2] partitiions, then you should format that partition as well, as the F drive.) Throughout all of this, I have presumed that you are using a Perstor Controller. If not, then you will have to substitute the DEBUG command for the PS2FMT command, using the address peculiar to your own controller, and trying the low-level format with different interleave factors as shown above. Most RLL controllers allow deviation from the "standard" interleave factors; however, some are inflexible. Just hope yours will allow you to select the optimum factor for interface with your own computer. If all has gone well during this procedure - and you were using the Perstor 180 controller card - you should now have one bootable DOS drive and two DOS DATA drives with a total writeable space of around 78 Megs! (With the Adaptec 2070A RLL, you'll get about 63 Megs, and with the Western Digital or OMTI RLL controllers you should be able to get a total of 65.5 Megs.) Whatever controller you use in this procedure, have fun! If you should have any problems with my instructions or this procedure, just call me at home (305) 851-0705 (you'll get my answering machine, but just speak up and if I'm home I'll pick up), or at work (305) 660-4084. Jim Russ 1121 Appleton Avenue Orlando, FL 32806 P. S. This is not intended as an indorsement for any particular sup- plier of hard drives, and the prices may vary (...probably DOWNward) from what I have listed in this document. However, I bought my own Miniscribe 3650 half-height drives from the firm listed below: HARD DRIVES INTERNATIONAL 1208 E. Broadway Rd. #110 Tempe, AZ 85282 ------------------------- To Order: 1 (800) 541-8387 (MC, VISA & American In Arizona: 1 (602) 967-3334 Express OK) ------------------------- Tech Support: 1 (602) 967-7435 -3- Other prices, as listed on Page 335 of the December 1987 Computer Shopper for this firm, are as listed below: ITEM PRICE SHIPPING ---- ----- -------- ST225 20 MB XT KIT Hard Drive (1/2 Height) 65ms WD Controller Cables & Manual $259.00 $8.00 ST238 30 MB XT KIT Hard Drive (1/2 Height) 65ms WD or Adaptec Controller Cables & Manual $289.00 $8.00 ST251 40 MB Hard Drive (1/2 Height) 28ms ONTRACK Disk Manager Diskette (Ver. 3.2) Cables & Manual $374.00 $8.00 ST4096 80 MB Hard Drive (1/2 Height) 28ms ONTRACK Disk Manager Diskette (Ver. 3.2) Cables & Manual $849.00 $8.00 Miniscribe 3438 30MB XT KIT Hard Drive Controller Cables & Manual $289.00 $8.00 Miniscribe 3650 40MB Hard Drive (1/2 Height) 52ms ONTRACK Disk Manager Diskette (Ver. 3.2) Cables & Manual $314.00 $8.00 Miniscribe 6053 40MB Hard Drive (1/2 Height) 28ms ONTRACK Disk Manager Diskette (Ver. 3.2) Cables & Manual $575.00 $8.00 Miniscribe 6085 71MB Hard Drive (Full Height) 28ms ONTRACK Disk Manager Diskette (Ver. 3.2) Cables & Manual $775.00 $8.00 -4-