IIRC the xx4x were bootable, the xx2x were not. I don't recall what other differences there were, but the 2920 had a dramatically simpler PCB. -Adam
On July 3, 2015 9:28:26 PM CDT, Hartmut W Sager hwsager@marityme.net wrote:
Oops, I may have gotten something wrong. Web information suggests that the AHA-2920 series cards are also bus-mastering, in which case, I can't remember what's different between AHA-2920 and AHA-2940. But I do remember that I used a lot of AHA-2940 series cards.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701, +1-204-515-1700
On 3 July 2015 at 21:16, Hartmut W Sager hwsager@marityme.net wrote:
Two of the most famous single-ended classic SCSI-2 host adapters of
that
era, using this 50-pin dense connector, were the Adaptec AHA-2920 non-bus-mastering series and the Adaptec AHA-2940 bus-mastering
series, for
PCI slot motherboards. They also sported an internal 50-pin 2-row
ribbon
connector for internal SCSI drives (and a 34-pin 2-row ribbon
connector for
floppy drives in the case of the AHA-2922 and AHA-2942, I think).
You could actually have both internal and external devices on the
single
SCSI chain (card in the middle), as long as you disabled the
terminating
resistor pack on the card itself. You then had to be especially
careful in
deciding which card/device would supply the terminating resistor
power. I
recall that Fujitsu hard drives were exceptionally problematic in
these
configurations.
I presume you (Trevor) know all about having to set each SCSI drive/device, including the host adapter, to a unique SCSI ID, yes?
Life with SATA and USB really is more pleasant.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701,
+1-204-515-1700
On 3 July 2015 at 19:48, Hartmut W Sager hwsager@marityme.net
wrote:
I'm a big SCSI guy, but ...
I too am an old SCSI fan, but my interest started to wane when so
many
SCSI signalling standards and connectors began to proliferate
together with
SCSI moving totally into the high-end server realm and away from
"ordinary"
peripherals. Oh, and then there was that "termination power"
headache
(usually selected/deselected by jumpers).
The device has a standard dense 50-pin 2-row connector. I thought
at
first that meant for sure LVD, but now I'm thinking it just means
ultra.
It doesn't even mean "ultra", let alone HVD/LVD. That connector
became
the norm during the single-ended classic SCSI 2 generation - to my
great
chagrin, since the Centronics 50-pin connector was so much better.
Is there a way to know what signalling this device uses based just
on
the connector?
No, but:
I checked all available interent specs, incl the original manual,
for
the device and *nothing* specifies anything other than "SCSI".
Since the original manual (lucky you to have that!) doesn't specify anything other than "SCSI", it is a near certainty that this isn't
LVD or
HVD, but simply good old single-ended classic SCSI (of at least SCSI
2
generation). It probably isn't "ultra" either, especially if it's a scanner or CD drive or similar slow device rather than a hard drive.
Hartmut W Sager - Tel +1-204-339-8331, +1-204-515-1701,
+1-204-515-1700
On 3 July 2015 at 16:06, Trevor Cordes trevor@tecnopolis.ca wrote:
I have an external SCSI device that I'd like to plug in on a 10-15' cable. The device has a standard dense 50-pin 2-row connector. I thought
at
first that meant for sure LVD, but now I'm thinking it just means
ultra.
I need LVD to get over 1.5M cable length, according to spec. LVD
lets me
go to 12M it appears. If it's just ultra then I'm SOL, I guess.
Is there a way to know what signalling this device uses based just
on the
connector? I checked all available interent specs, incl the
original
manual, for the device and *nothing* specifies anything other than "SCSI".
I'm a big SCSI guy, but my memory on the subject is starting to get hazy due to disuse... _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
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