test-drb April 1999

test-drb@ccmp.vtda.org

170 participants
1190 discussions

Will The Grand Master Of Disk Controllers step foreward?

by edick＠idcomm.com

-----Original Message----- From: Eric Smith <eric(a)brouhaha.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Friday, April 16, 1999 1:45 AM Subject: Re: Will The Grand Master Of Disk Controllers step foreward? >> Specifically the WD-1000-5 disk controller. These are the ones that >[...] >> If you are intimately familiar with this legendary interface, I would >> like to hear from you. I need to figure out how to modify it for 8" >> harddrives. > >Regrettably I no longer have the manual or schematics for these, so a lot >of this is from memory. > >The WD1000-5 was the WD1000 repackaged on an 8" * 5.75" board, to match the >form factor of 5.25" drives. There's more to the difference than that. For one thing, the WD1000 series used the WD1100 chipset and an 8X300 microcontroller to run the whole thing, while the WD1000-05 and -08, as well as the later models, used the WD1010 chip along with other combinations of the 40-pin support chipset of which WD1014, which was, in at least one incarnation, an 8041. >The original WD1000 and WD1001 had both 34 and 50 pin drive control >connectors. I'm guessing that the WD1000-5 left the 50 pin connector out. >However, you only need to scramble the pins appropriately, as the actual >signals are the same. All odd pins are ground on both connectors; the others >should map thusly: > > 34-pin 50-pin signal > > 2 2 *RWC reduced write current > 4 4 *HS2 head select 2 > 6 40 *WG write gate > 8 8 *SC seek complete > 10 42 *TK0 track 0 > 12 44 *WF write fault > 14 14 *HS0 head select 0 > 16 NC > 18 18 *HS1 head select 1 > 20 20 *IDX index > 22 22 *RDY ready > 24 36 *STEP > 26 26 *DS1 drive select 1 > 28 28 *DS2 drive select 2 > 30 30 *DS3 drive select 3 > 32 32 *DS4 drive select 4 > 34 34 *DIR step direction (in when asserted) This should look pretty much like 8" floppy disks. An early controller I built used an FDC chip to drive these control signals, as the 8" Winchesters had the same maximal step rate back then as the 8" double-headed FDD's. That's overkill, and the FDC expects to see things from the data stream which close the loop, and it won't see them. Open-loop, e.g. simple head-positioning command operation is possible, at least to see if the drive's mechanical functions are working. An enterprising approach would be to operate the drive with a pair of small single-chippers one fairly slow one to handle the head positioning, and the other a fairly quick one to modulate the data, e.g. with ERLL code as was used in the PERSTOR controllers. >The radial data connectors are the same for both drive sizes. Yes except that some drives extracted clock locally and sent it on the data cable as well. For that reason, it would be advisable to stick with the 4.34 MHz data rate. Keep in mind, also, that while the wide cable is driven with open collectors, the data cable is intended to be driven with differential drivers/receivers of the MC3486/87 or 26LS31/32 type. >The bigger problem is that 8-inch drives used a data rate of 4.34 Mbps rather >than 5 Mbps. I seem to recall that the WD1000 had a jumper setting for this. >If they removed the 50-pin drive control connector, they probably also removed >the jumper and supporting circuitry. Western Digital was somewhat confused about how they should number their controller models back in those days, and the scheme got muddled, but as I recall, and I have some controllers to prove it, the data rate was fixed on the board at the factory, in some cases, particularly the larger WD1000 boards with the WD1100 chips + 8X300 on board, had a discrete VCO as opposed to the 74S124 or the LS624 they later used. These VCO's had to be tuned quite carefully and a procedure was included in the instruction manual. There were jumpers for accomplishing this tuning operation on nearly every type of board in this entire family, but one needed both a crystal and a retuned VCO for the PLL, not to mention changing the passive components in the integrator (LPF) of the clock extraction circuitry. The process of setting the VCO center frequency was not terribly difficult, but one had to know which jumpers to remove at which stage of the operation because there were inputs to the circuit which had to be active and other which had to be passive at different stages of the operation. >> Also, does anyone have docs for the Quantum Q-2040 8" >> Winchester? I dunno what kind of power to feed it (24v sounds correct, >> but I seem to recall it used 110vac also!), and so on. > >No data here, but almost certainly not 110 VAC. Probably 24V AC and 5V DC. The power connections are precisely what is used with an 8" FDD, including a 110 VAC supply for the spindle motor. Don't forget that some 8" drives had to be fed a negative 5V supply while others could swallow either -12 Vdc or -5, depending on a jumper because they had on-board regulation. You have to look for the regulator and ensure it has the jumper which bypassed it in the correct position. >You *might* be able to get a Q2040 to run at 5 Mbps, but I've never personally seen it done. We, meaning my people and I, tried this several times and never got it to work reliably with Shugart drives. They did some signal processing on the data, and included clock on the cable, so you might be able to skip the VCO retuning if you can find the "right" place to inject this conditioned clock in the data/clock recovery circuit. I'd be surprised to find the Quantum drives did things much differently, as they had to be compatible with the Shugarts, and some controllers, e.g. Intel's, relied on the drives or other external circuitry to extract clock.

25 years, 8 months

Abort, Retry, Ignore, Fail? (Was: stepping machanism

by Philip.Belben＠pgen.com

>>Hang on. I don't claim to be fluent in C, so I was keeping out of this debate, >>but this is well weird! As I understand it, you don't have to prototype >>anything in C - or shouldn't have to. The only C compiler I've ever used >>doesn't even SUPPORT prototypes! > > I'm just not good with jargon. I meant declaring. In perl, everything is > dynamically allocated. You don't do "int foo; foo=5;", you just do > "$foo=5;". Oh, I see. In that case I agree. Philip.

25 years, 8 months

More InnfoGraphics auction listings in Portland, OR, USA

by Innfogra＠aol.com

I have added more info to the classic computer section of the Innfographics auction web page. http://members.aol.com/innfograph It will be an interesting sale. Paxton

25 years, 8 months

Remove My Email Address From the Classiccmp List

by mikeparadiso＠worldnet.att.net

Please remove my email address from the classiccmp list. This email address is now being used by my business. I will be getting a new address just for the classiccmp list. Thanks, Mike mikeparadiso(a)worldnet.att.net

25 years, 9 months

Worst of Both Worlds (IMPORTANT)

by max82＠surfree.com

I saw a blurb in the newspaper (available at http://www.tcm.org/join_forces.html) that The Computer Museum and The Science Museum in Boston, MA are merging. It says that 'The History Center' of the Computer Museum is now in Mountain View, California and is applying to become a separate institution. Anyway, this shuffling may mean lots of stuff being thrown out or damaged. The Computer Museum may opt to clean out its basement... --Max Eskin (max82(a)surfree.com) http://scivault.hypermart.net: Ignorance is Impotence - Knowledge is Power

25 years, 9 months

OT: Re: Time to declare State of Massachusetts the ENEMY! He

by ethan_dicks＠yahoo.com

--- Bill Pechter <pechter(a)pechter.dyndns.org> wrote: > > > > 30pin simms of any kind is very hard to come by now compared to > > ease of obtaining used 72pin of all types. > > I'll swap 4 4mb 30 pit Simms for 16mb true parity 72pin simms in a minute. > (The Sparc IPX used 33 bit wide Simms) but 36 will work. I'd do the same. I have more 4Mx9 SIMMs than I need, and I do need between two and four 16Mb true parity 72-pin SIMMs for a SPARC-LX (60ns) or my Alpha (70ns). -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

25 years, 9 months

PET rediscoveries and questions

by ethan_dicks＠yahoo.com

While going through the stuff on my top shelf, I ran across some boxes I aquired when the local Commodore dealer went out of business several years ago. Among the booty are a couple of special boards that I need some more info on before I can put them to use... I have these two boards, new in the box, with all the cables, etc., one Computhink (324042-01) and one BMB (324038-01). There's excellent scanned docs on ftp.funet.fi as well as three demo disk images (which I believe are very recent). I even happen to have one SuperPET language reference manual. Do I need anything else? How do I go about selecting the different languages in there? Does anyone out there have a SuperPET with docs/software? I'd love to find out a little bit about it before I go mucking around inside an 8032. Thanks, -ethan _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com

25 years, 9 months

8" drive on a pc controller

by bill＠chipware.com

> > Shouldn't you gentlemen be considering, instead of which format, at what > > kind of DRIVE is involved? > > Excellent point, as I have been using a Mitsubishi that I set at 6ms. Ah! Shugart and Seimens drives, requiring 15ms.

25 years, 9 months

MINIMUM Requirements (Was: OT: Re: Time to declare

by KFergason＠aol.com

In a message dated 4/15/99 9:11:07 PM Central Daylight Time, cisin(a)xenosoft.com writes: > billg said that 95 would work with 4M, but I was never able to run > anything but "safe mode" (I have an NEC VERSA 486 that rejects memory > expansion) > my girlfriend runs 95 on a 386-20 dec laptop with 4M. it works. printing a page on the Laserjet takes 5 minutes.

25 years, 9 months

Xerox System 60?

by dastar＠ncal.verio.com

Does anyone know what the purpose of a Xerox System 60 is? Sellam Alternate e-mail: dastar(a)siconic.com ------------------------------------------------------------------------------ Don't rub the lamp if you don't want the genie to come out. Coming this October 2-3: Vintage Computer Festival 3.0! See http://www.vintage.org/vcf for details! [Last web site update: 04/03/99]

25 years, 9 months

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test-drb April 1999