Recognizing an ACB-4000A SCSI device?

[matthew180]

Greetings,

I need to back up an ST-225 that currently has an Adaptec ACB-4000A card attached to the bottom. I had never heard of such a thing but once I learned it was an "Winchester" to SCSI adapter I though "no problem", SCSI is backwards compatible, and I just happened to have a PCI host adapter with a 50-pin connector and BIOS utilities.

However, after hooking everything up, letting the ST-225 spin up and the ACB-4000A do its initialization, I would start the PC, enter the SCSI host BIOS routines and scan for devices. Needless to say the drive is not recognized. So I figured maybe the host adapter was just too new, so I pulled out an older (circa 1988) ISA based host adapter (my motherboard is old enough to have 1 ISA slot), made a DOS boot floppy with drivers, and tried that. Alas, even the older SCSI host does not find the drive either.

I then thought I could just remove the ST-225 from the ACB-4000A and plug it directly into an old MFM controller; let's see where did I stash that 286 I had 12 years ago... I don't have my 286 era hardware any longer and finding a box that's newer than an XT but older than a 386 is proving to be very difficult! But that's another story all together.

At any rate, if I could just read the disk via the ACB-4000A I'd be all set. I do know it works because it is out of a dedicated computer (part of a 3-axis winding machine's PLC) and it works in that environment. Well, kind of, the drive is starting to blow errors (go figure, it's only 24 years old), thus my needing to back it up and get it replaced.

Any insight would be greatly appreciated!

Thanks,
Matthew

 

[Al Kossow]

ACB 4000's

ACB 4000's

ACB 4000's are early adapters which require you to send commands to configure the geomentry of the drive.

 

[matthew180]

Any idea how I could go about doing that with a newer SCSI card? Is that a normal thing for a SCSI host adapter to have to do?

Matthew

 

[modem7]

I need to back up an ST-225 that currently has an Adaptec ACB-4000A card attached to the bottom. I had never heard of such a thing but once I learned it was an "Winchester" to SCSI adapter I though "no problem", SCSI is backwards compatible, and I just happened to have a PCI host adapter with a 50-pin connector and BIOS utilities.
However, after hooking everything up, letting the ST-225 spin up and the ACB-4000A do its initialization, I would start the PC, enter the SCSI host BIOS routines and scan for devices. Needless to say the drive is not recognized.

If the ACB-4000A is a SCSI device, then it should be showing up in a device scan, providing that you are using a compatible host adapter and termination, etc. set correctly.

Part of the ACB-4000A user guide is at http://download.adaptec.com/pdfs/user_guides/acb4000_um.pdf
Looking at that user guide, you may need to alter jumpers G-H and I-J to suit the SCSI host adapter.
Looking at that user guide, you need a SCSI 1 adaptor that uses unbalanced signals (page 3-12).

At tech school I never advanced past SCSI 101. The paragraph on page 3-12 concerning the reset line might be important. Could it be that your host adapter is sending a reset during initialisation and the ACB-4000A is enterpreting that as a command to "get off the bus".

I then thought I could just remove the ST-225 from the ACB-4000A and plug it directly into an old MFM controller

Different controller cards can use different controller chips, and different controller chips can use different low-level formats. You would need to find an MFM controller that lays down the same low-level format as the ACB-4000A. Once you've overcome that hurdle, you could use early versions of GHOST with the appropriate switch/s to create a raw image file from the ST225.

 

[JohnElliott]

I tried something similar a few years ago with a drive out of an ICL Quattro. In my case, the bridgeboard turned out to be SASI rather than SCSI. I never got it working; the closest I got was with a patched copy of Linux 2.0.39 and a Future Domain controller. In the end the drive started making nasty mechanical noises and I gave up.

Here's the whole thread from comp.periphs.scsi:

http://groups.google.co.uk/group/co...read/thread/f33df082a02fff36/554c6bcc8dcaf0d6

 

[matthew180]

I did find that PDF (what a nice scan, eh...) and tried a jumper on I-J (extended command set), but never tried the G-H (DMA transfer rate) jumper.

How do I know if my SCSI controller has unbalanced signals? I don't know a huge amount about SCSI and wonder if balanced or unbalanced is the norm? I'll go try to dig up that info about the two controllers I have.

I don't know about the reset. I let the ACB-4000A power on and initialize for about 30 seconds before powering on the computer, so if the controller does send a reset then it does not happen during ACB-4000A initialization.

JohnElliott
I tried something similar a few years ago with a drive out of an ICL Quattro. In my case, the bridgeboard turned out to be SASI rather than SCSI.

What is the difference between SASI and SCSI? I suppose an SASI controller would be next to impossible to get... Off to Google I go.

Matthew

 

[modem7]

How do I know if my SCSI controller has unbalanced signals?

You need to look in the user manual / tech ref, etc.

I don't know a huge amount about SCSI and wonder if balanced or unbalanced is the norm?

From my experience of the time (CD-ROM chassis' and tape drives), unbalanced with passive termination was the norm.
Balanced would have been used to get long SCSI cable length or used in noisy environments.
I'm sure there are lots of SCSI tutorials on the Internet.

I don't know about the reset.

I thought someone with good SCSI knowlege would have made a comment. That 'hard reset' may not be a problem. It does highlight that there were some different variations or enterpretations of SCSI floating about. Even today when say buying a tape library, I'll seek from the manufacturer a list of known compatible host adapters, and sometimes I just play safe and buy the appropriate Adaptec board (a bit like playing safe in the 80's and buying IBM) because you can be sure that the manufacturer has tested their equipment for compatibility with Adaptec.

What is the difference between SASI and SCSI?

That ACB-4000A user guide was the first I've heard of SASI.

 

[sbus]

acb-4000a manual and info

acb-4000a manual and info

The disk interface on the ACB-4000 is ST-506; that's the type of disk drive it controls.

It connects to the host via single-ended SCSI (50-pin).

The manual for the ACB-4000A is at:

http://www.adaptec.com/en-US/support/_eol/acb/ACB-4000A/_docs/acb4000_um_pdf.htm

The last time I saw that card, it was used in a Sun-3. I have a few Sun-3's around here somewhere, with ACB-4000s!

Here's the specs for the ACB-4000A:
=====================================================
The ACB-4000A Features

SCSI standard command set, plus SCSI extended optional and vendor unique commands
1-to-1 interleaving of the disk
Sector level defect skipping
Autoconfiguration of the drive
Controls both 5 1/4" and 3 1/2" ST506/412 type Winchester disk drives
32-bit ECC on both ID and data fields
Variable sector sizes of 256 bytes, 512 bytes, and 1K bytes
Support of a high-speed data search
Support of wedge servo drives such as Microscience, Syquest, Tulin and Quantum
13-microsecond high performance seek step rate
Suppports 16 heads and 2048 cylinders
Power-on diagnostics and jumper enabled self-diagnostics for controller self-checking
The ACB-4000A supports hard sectored drives
The ACB-4000A supports removable media drives

Hardware System Requirements

ACB-4000A Controller Board
Host CPU
SCSI Host Adapter (or equivalent SCSI port)
20-pin, 34-pin (drive), and 50-pin (SCSI) cables
Power supply, +5 VDC and +12 VDC

Software System Requirements

Host Operating System
I/O driver for Host Adapter
Uses written format utility
(Optional) Landing zone utility
(Optional) Any user-defined controller utilities

Board Dimensions

7.75" x 5.75" x .075"
19.7 cm x 14.6 cm x 1.9 cm

Power Consumption

+5 VDC +/- 5%, 1.5 Amps (max)
+12 VDC +/- 10% at 300 Amps(max)

Operating Characteristics

0°C to 55°C (32°F to 131"F)
10% to 95% non-condensing relative humidity
Altitude feet: Sea level to 10,000

Storage Characteristics

-40°C to 75°C (-40°F to 167°F)
Altitude feet: Sea Level to 20,000

MTBF (mean time between failures, Bellcore)

20,000 POH at 55° C