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bootable SCSI ISA cards

haightc

Experienced Member
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Jan 13, 2016
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SeaTac, WA
I have two ISA SCSI cards neither appear to be boot or rather recognizable from the BIOS as far as I can tell.
Can you recommend some boot-able 16bit ISA SCSI cards to be on the lookout for?
 
My go-to 16 bit card is the Adaptec 1522/1542 card. Built-in floppy controller too, and depending on which revision, the floppy can often do single-density.
 
Just curious--do either of your non-bootable cards have a socket for a PROM? (i.e. what are they?)

I like the Future Domain 16xx cards as well as the ones made by DTC and Ultrastor.
 
None of them have sockets, I have the fallowing SCSI cards
Symbios SYM20403
Adaptec AVA-1502E
Must Systems AZ-SCSI

I also have a sound card with a built in IDE interface, but no internal expansion bays. However from what I understand if I get an XT-IDE bios chip that might open up my options. Also my 3com Etherlink III also doesn't have a a ROM socket. Although I am still a little muddy on how to get the chip and how it really works.
 
I have an adaptec SCSI that came with my SCSI Floptical - a 21mb SCSI Floppy Drive and I actually have 5 floptical disks. It also reads standard 3.5" floppies as well and boots from the drive.
 
JUst an idea...

On the couple non-bootable SCSI controllers I have (DOS machines), what I did was use a small IDE drive to hold the AUTOEXEC.BAT and CONFIG.SYS files, as well as the SCSI drivers. Once the SCSI drivers are loaded, all the other software can be on the SCSI devices.

The IDE drives I used were only 80mb.

Joe
 
I also have a sound card with a built in IDE interface, but no internal expansion bays.

JUst an idea...

On the couple non-bootable SCSI controllers I have (DOS machines), what I did was use a small IDE drive to hold the AUTOEXEC.BAT and CONFIG.SYS files, as well as the SCSI drivers. Once the SCSI drivers are loaded, all the other software can be on the SCSI devices.

The IDE drives I used were only 80mb.

Joe
Booting from a floppy seems like a reasonable alternative.
 
I can speak for the Adaptec 1502 and Symbios 20403--they were bare-bones controllers sold to the scanner market. You can get ASPI support (and hence disk and CD) for them, but there's no provision for booting.

After all, why would someone want to boot a scanner? :)
 
This is sort of a weird resurrection of a year old thread, but if anyone is still looking of decent ISA bus bootable SCSI controllers then you can't go wrong with an Adaptec 1542, as was mentioned near the beginning of this thread. I must have a few of the different revisions of them around. They should be fairly easily found at cheap prices.
 
This is sort of a weird resurrection of a year old thread
Was thinking same...

but if anyone is still looking of decent ISA bus bootable SCSI controllers then you can't go wrong with an Adaptec 1542
ALSO thinking the same.

The entire 1542 line are in my experience the BEST in ISA SCSI adapters, if for no other reason than that unlike most other ISA SCSI adapters, it actually seems to properly implement being hot-pluggable.

Back in the early 1990's I was working for a place where one of the clients had pretty much built their entire business around the Compaq portable III using a custom card to turn them into EKG machines. They also had a desktop version for calibration and office testing, but the portable was more popular with hospitals... but they had a problem.

1) Extra hassle of an external parallel drive since the data had to be shipped off for proper analysis.

2) Compaq PC3's were drying up in the supply channel since they were already out of production

3) Next generation information gathering required more powerful systems in both processors and storage capacity

4) The custom card for the PC3 was unreliable and often broke loose in shipping.

But I remembered from the back of Computer Shopper that there was a company selling PC3 style cases -- nearly identical -- but with a full height floppy bay, internal room for a 3.5", and that took a standard mini-AT motherboard... So I got my boss to order one for evaluation, built it up as a 486DX/2-66 with a 1542C, removable SCSI 1 gig hard drive (which was batshit storage for a PC in '92), internal 512 meg for booting and software, and one of the client's desktop cards plugged into it.

Which from the time I showed it to the client to the time I left the company, they bought those suckers like hotcakes. We had several hundred deployed 'in the wild' with pretty much every model of 1542 Adaptec ever made, with zero failures, zero issues, and greatly sped-up deployment. They were just rock solid reliable and even replaced their desktop models.

... and being we're talking about a lunchbox where they would get shlepped around by medical personnel not computer experts, that's a harsh environment where failures should (and typically were) common. See the pile of junk actual Compaq's the client had piled up in the corner. (Always regretted not asking "Hey, could I have a couple of these?")

Though some custom changes I made to the case of the PC3 clones helped with the shipping issues as I took a page out of the PC Jr's playbook, and took some lexan and hot-cut slits into it which was then epoxy'd to the lid. When you put the cover back on it, the slits lined up with the control cards meaning they couldn't lift up out of their sockets during shipping. Was a cleaner solution than going down in there with a hot-glue gun like you saw so many companies do.

If you can find them the 1542CF -- here's an older pic of one from my collection:
AHA-1542CF.jpg


Is the best of the best of the best -- with honors -- to come from Adaptec for the ISA form factor. I usually HATE software controlled hardware settings, but the card never failed me, it's auto-detection of other hardware is (in my experience) bulletproof in that it even seems to go "hey, there's ROM here, let's not put our ROM there" and show a "Rom Conflict, check AHA-1542 Address switches" message -- and is still PRE "plug and play" meaning you still retain far more control over it from its ROM than you would relying on the system BIOS to place the IRQ's, DMA channels, and ports.

But if you want to go the old-school jumper route, 1542B is a fine and dandy card that is otherwise identical.

Hell, that 1542CF pictured above is in my 286-20 clone driving a 1 gig seagate right now.... though that drive is probably being pulled to see if it will work with a ST-02 V3.0.0 in a XT clone.

Bottom line, if I need SCSI and have a 16 bit ISA slot available, AHA-1542 or GTFO.
 
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I have a 1540A (1542 without floppy section populated); older version on a full-length ISA card. If you're interested, drop me a line. I have the 1542CF (and a pile of others) already.
 
One thing to note with the Adaptec AHA-1542 is that the on-board FDC controller chip used varies with the different versions.

That should only be an issue if you want to read and write images of certain disk formats which are non-standard for PCs.

The FDC registry link here says the earlier AHA-1542 versions use some flavor of an DP8473 FDC controller while later ones use some flavor of an 82077 controller, which apparently does not support Double-Density with 128 bytes sectors.

http://www.classiccmp.org/dunfield/img/index.htm
 
But if you want to go the old-school jumper route, 1542B is a fine and dandy card that is otherwise identical.
1542B has one problem: 1 GB HDD size limit in BIOS.
Apparently there was some BIOS/firmware update to allow up to 8.4 GB, but I can't locate it. Any help?
 
BTW, another question to 1542B users:
That adapter has jumpers to select DMA speed: 5.0, 5.7, 6.7, 8.0 MB/s, default is the slowest one, and I'd like to set it to the fastest safe speed.
The manual reads: "See Appendix A for system timing requirements."
But I can't find that appendix, anybody has it?
 
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I have two ISA SCSI cards neither appear to be boot or rather recognizable from the BIOS as far as I can tell.
Can you recommend some boot-able 16bit ISA SCSI cards to be on the lookout for?

I don't mean to "jump" this thread but I wonder if anyone can recommend an 8-bit ISA SCSI adapter with a BIOS suitable for booting a hard disk?

Thanks,

-CH-
 
I don't mean to "jump" this thread but I wonder if anyone can recommend an 8-bit ISA SCSI adapter with a BIOS suitable for booting a hard disk?
Seagate ST01 and ST02 are pretty common, but their BIOS has some severe HDD size limit.
 
A Trantor T128 or T130 (that hasn't been stripped for CD-ROM only support) are both pretty decent. There are some nice DTC 8-bit boards, such as the 3180--apparently, they're harder to find. And Future Domain put out an 8-bit board as well.

Note however, that most 8 bit cards use 6-byte CDBs, which limit them to about 1GB of addressability.
 
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