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View Full Version : BEST disk controller for 286 build is... AHA-1542CF?



deathshadow
December 31st, 2013, 11:30 AM
I've been putting my old AT system back together after decades of the motherboard sitting in a box... I've got a fairly nice setup of stuff for it in terms of a G2 Ega, Aria 16 sound card and RampAT card -- that last one I'm still struggling with on parity errors that I don't think is the ram's fault :(

But for the life of me I couldn't get IDE working with it. Back in the day it had a pair of 42 meg RLL drives in it, and the mobo BIOS's type 47 doesn't seem entirely compatible with any of my IDE controllers, or it just hates the fact the smallest IDE I have right now is 200 megs...

So I said 'to blazes with this' and tossed in one of the many SCSI controllers I happen to have lying around... and, well...

Is it just me, or was the AHA-1542CF the BEST disk controller ever made for the AT Bus? SCSI, MFM, RLL, IDE -- doesn't matter which -- Was there ever anything better than it?

For those of you not familiar with it:
http://www.deathshadow.com/images/AHA-1542CF.jpg

Adaptec EZ-BIOS that pimp-slaps even the crappiest AT BIOS into shape, floppy controller (that always seemed 'faster' somehow), software level turning on/off termination on the card, Configurable to a half dozen different ports, ability to co-exist with other cards of the same type, that nice big robust 50 pin Centronics D on the back instead of the rinky little crap that came later... The ENTIRE 154x series were absolutely great cards, but the 1542CF was like the pinnacle of the art of making a disk controller.

I mean, I'm sitting here with a 10mhz 286 that's got a 4 gig 10K RPM Seagate Cheetah... So I'm pushing 2.8megs/sec according to Norton's Sysinfo, even with the warning about the disk controller blocking the seek time test.

I'm half tempted to drag out my 50 to 68 pin converter to see how one of my 9 gig 15K RPM cheetah's works out for it... as it is I know one of those is going in my AM386/40 build since I've got two more 1542CF sitting here with nothing better to do.

Makes me wonder though, were there ever any good 8 bit SCSI controllers for PC? I've seen lots of them that were 'dumb' with no boot ROM or anything -- was there an equivalent? Be a hell of a lot less hassle than the whole XT-IDE thing.

deathshadow
December 31st, 2013, 11:37 AM
Oh wow, was digging through my parts bin and came across a Jaz drive -- which if I turn on the 'auto-mount removable disks' option in the Adaptec EZ-BIOS DOS sees it without any extra drivers.

I had forgotten how much I LOVE Adaptec cards... Starting to think that Athlon 600 I was gonna use as a linux box in the garage is now getting one of my 2940 cards. I do have a 18 gig 15K Cheetah as well...

Caluser2000
December 31st, 2013, 11:51 AM
Happy new year ;)

Nice to see. ISA SCSI controllers seem to be a bit thin on ground in this neck of the woods. Well those that we not in the industry anyway. I'd imagine that would be the case with a lot of folk putting older machines into service hense, a need for the XT-IDE thing.

Stone
December 31st, 2013, 12:06 PM
I've got the following if any happens to be of interest:

Teac SD-340 43MB IDE HD

Seagate ST3096A 80MB IDE HD

WD Caviar 1170 170MB IDE HD

WD1003-WAH MFM/FDD Controller

WD1003-WA2 MFM/FDD Controller

WD1002A-27X RLL Controller

pearce_jj
December 31st, 2013, 12:06 PM
Is it using DMA? 2.8MB/s seems high (by my calculations).

Chuck(G)
December 31st, 2013, 12:10 PM
Don't confuse SCSI with other interfaces with regard to ease of use. Early SCSI certainly had plenty of "voodoo", particularly when it involved more than one device type on a bus. Most better 16-bit ISA SCSI controllers were pretty good (Future Domain, Adaptec, DTC, Ultrastor..) but expensive. One advantage that SCSI had was an ANSI standard specification for everything from disk drives to tape drive robots. SCSI was expensive when compared to other consumer-level interfaces.

ATA started out with the logical move of reducing cost by integrating the disk controller with the drive electronics--other devices came later. If you're fortunate enough to run across an IDE controller with its own BIOS (e.g. Promise), it can be just as easy to attach a hard disk as any other interface. Its objective was to lower cost--something it achieved wonderfully.

I used ESDI drives for quite awhile and again, never had a hint of trouble. But ESDI, like SCSI, isn't your usual consumer-grade interface. However, ESDI, like ST506, was confined to disks and not a general-purpose interface.

dorkbert
December 31st, 2013, 12:48 PM
ATA started out with the logical move of reducing cost by integrating the disk controller with the drive electronics--other devices came later. If you're fortunate enough to run across an IDE controller with its own BIOS (e.g. Promise), it can be just as easy to attach a hard disk as any other interface. Its objective was to lower cost--something it achieved wonderfully.
And to think that when I was still working there, we threw out a bunch of those over a period of about two years...

Caluser2000
December 31st, 2013, 01:01 PM
Hmmm I've still got a Promise IDE multi i/o card with it's own bios.

Cloudschatze
December 31st, 2013, 01:06 PM
... RampAT card -- that last one I'm still struggling with on parity errors that I don't think is the ram's fault :(
Try the "/Z" driver switch.

paul
December 31st, 2013, 01:10 PM
There is no question that Adaptec products are generally top-notch. My two 1542CPs have the high density SCSI-II external connectors which I prefer as they match the few peripheral boxes I have. I remember paying US$200 for a AHA-1522 in the '80s and I think the 1542 was at least a hundred more.


Makes me wonder though, were there ever any good 8 bit SCSI controllers for PC? I've seen lots of them that were 'dumb' with no boot ROM or anything -- was there an equivalent? Be a hell of a lot less hassle than the whole XT-IDE thing.

I have an NCR-based bootable 8-bit card from Storage Dimensions. It works well on my 5150 PCs but the partitioned and formatted hard disk is not readable by the Adaptec controllers. On boot the BIOS presents the optimistic name "Data Cannon."

16629 16630

fatwizard
December 31st, 2013, 02:08 PM
All of the Adaptec SCSI controllers I have worked with were finely crafted, and nearly bulletproof, but I would never have owned one "in the day" because of the high cost.

As for 8bit ISA SCSI cards, I have ended up with three Seagate ST01 models. They are robust, but pig slow, and if the card doesn't have the latest BIOS rev. you will be limited to old/small drives. These cards have all the SCSI voodoo you could want. For instance, even though the docs claim support for up to seven devices, I have never gotten any two of my SCSI drives to work at the same time.

One other note about the ST01. If there is no device connected to it, or a device that isn't functioning, or not terminated correctly, the card will report a very distressing "Host Adapter Failure" on startup. In fact, that's just how I ended up with my second card. I hunted one down when I believed that error message. I had mounted a 250 meg Quantum Pro Drive in an external enclosure and that drive just wouldn't accept external termination. Worked fine when I put the termination resistors back on the drive itself.

Voodoo indeed.

deathshadow
December 31st, 2013, 02:45 PM
Try the "/Z" driver switch.
Bombs out 'invalid option' when running the config.exe (disk is normally a booter) -- Did I mention it's an Acculogic RAMpAT! and not a AST Rampage AT? I don't think it has a 'driver switch' that would effect if BIOS bombs at the 1024k mark with a parity error with the card inserted...

Insert card, throw switch to reset, back to normal, boot to the floppy it came with, sees the 4 megs RAM. Reboot, system throws parity error when it gets to the card in the bios memory test. If I bypass the BIOS test, himem.sys chokes on it too. (Always loved that switch to 40 column mode for **** knows what reason)

... and I'm sure the sticks are 1x9 -- first thing I eliminated as a possible problem. I think this board is just toast since neither this build, nor my Model 30/286 likes it.

Chuck(G)
December 31st, 2013, 03:19 PM
If anyone is really interested in Adaptec adapters, I've got a couple of AHA-3985 PCI cards. Basically 3xAHA2940 adapters on a board. The BIOS ROM can support up to an 8 GB RAID configuration in DOS without drivers. Mostly intended for NetWare. PM me if interested.

Manual (http://download.adaptec.com/pdfs/user_guides/aha398x_ug.pdf)

Stone
December 31st, 2013, 04:40 PM
... and I'm sure the sticks are 1x9 -- first thing I eliminated as a possible problem. I think this board is just toast since neither this build, nor my Model 30/286 likes it.Those 1X9 sticks are 9 chip, not 3 chip, right? I've seen 1X9 3 chip SIMMs fail to work where 1X9 9 chip SIMMs work fine. And you've tried other 9 chip memory sticks with the same results? Have you tried the board with just two sticks? Have you then tried it with the other two sticks?

Cloudschatze
December 31st, 2013, 05:00 PM
Bombs out 'invalid option' when running the config.exe (disk is normally a booter) -- Did I mention it's an Acculogic RAMpAT! and not a AST Rampage AT? I don't think it has a 'driver switch' that would effect if BIOS bombs at the 1024k mark with a parity error with the card inserted...

This may not actually apply to the RAMpAT! at all (I'm using a RAMpAT!-Plus), but that switch would only apply if the card is configured for straight EMS besides, and would be used against the Acculogic MM.SYS driver. In my Tandy system, it resolved the parity errors that driver would produce, but your configuration is obviously different.

Cloudschatze
January 1st, 2014, 12:06 PM
I'm mostly familiar with Trantor's 8-bit SCSI options, and currently use both T-128 and T130B cards. The T-128 is memory-mapped, and very compatible across systems, but doesn't provide SCSI TERMPWR to the bus, and is cylinder-limited (1GB) besides. The T130B rectifies the TERMPWR omission, but has the same cylinder limitation, and is I/O-mapped, making it boot-incompatible in a number of Tandy systems.

On paper, the Rancho Technology RT1000B (w/8.20 BIOS) is the "best" 8-bit adapter I've come across, given its BIOS support for Floptical drives (allows the Floptical to become the "A:" drive), use of extended BIOS translation (allowing for drives up to 8GB in size), TERMPWR, and for being a memory-mapped device besides. Whew! I've yet to upgrade the BIOS on my card though, so its supposed greatness is mostly hypothetical until I can test the ASPI support.

Anonymous Coward
January 1st, 2014, 03:40 PM
That Storage Dimensions NCR card that Paul posted is the coolest looking 8-bit SCSI controller I've seen so far.

dano
January 29th, 2014, 11:33 AM
I was using a couple old 100 meg IDE drives in my IBM 5170 (and the BIOS wouldn't even let me use the full capacity) and finally got tired of bad sectors and errors so I installed an Adaptec AHA-1541A, basically the old full length version of the card, that I was lucky enough to have saved from the scrap pile at work. The card and the equally-old full height Maxtor SCSI drive have been working great for years now, and no more BIOS limitations. I highly recommend SCSI for these old AT-class machine - if for no other reason it makes it easier to use newer hard drives without BIOS headaches.

pearce_jj
January 29th, 2014, 11:42 AM
I'd be interested to know what real throughput these systems deliver. My DOS filesystem throughput tester (http://www.lo-tech.co.uk/wiki/DOS_Disk_Tester) should give some easy numbers, for anyone willing to give it a whirl.

Trixter
January 29th, 2014, 01:21 PM
Is it just me, or was the AHA-1542CF the BEST disk controller ever made for the AT Bus?

When I worked at Mark Williams Company, the kernel developers (who also wrote the drivers) cited the 1542CF as the best controller for the operating system they were developing (Coherent), stating the ease of development and the card's ability to use scatter-gather (https://en.wikipedia.org/wiki/Vectored_I/O).