Archived from groups: comp.sys.hp.hardware (
More info?)
For all the reasons you mention, Christian, I would recommend a separate SCSI
host adapter for the scanner. Something like an Adaptec 2900-series, which are
old, reliable, and fully supported by most any operating system. But the
adapter should not be a "wide" with a W suffix, which have only 68-pin external
connectors.
Use of a separate adapter eliminates any problem with conflicts among SE and LVD
devices... Ben Myers
On Sun, 5 Jun 2005 11:38:28 +0200, Christian =?ISO-8859-1?Q?D=FCrrhauer?=
<cduerr@geog.fu-berlin.de> wrote:
>On the seventh day, Brcobrem wrote...
>
>> Well, it failed on me again via the USB connection (for the hundredth
>> time). So I'm going to go with Christian's suggestion and go Scsi.
>
>:-(
>
>> For those who may be interested, my motherboard has a scsi chip on it
>> that provides a 50 pin Scsi1 connector, a 68 pin Scsi2 connector, and a
>> 68 pin Ultra Scsi2 connector. The motherboard-to-backplate adapter that
>> came with the motherboard is 68 pin. So how to go from 68 pin female on
>> the backplate to that 50pin miniture female on the HP Scanjet 6200C ? I
>> spoke to cablestogo.com and they recommended their "SCSI external
>> cable - HD-68 (M) - HD-50 (M) - 6 ft", P/N 08177.
>
>Don't (repeat: don't!) do it this way if you can prevent it! Assuming the
>68pin backplate connector is used to connect to the Ultra Wide 2 SCSI part
>of your controller (which is almost certain since I haven't heard of
>anything else), this will not only decrease the allowed cable length for
>LVD scsi (also called Ultra Wide 2 SCSI, used in U160 and U320 too), it
>will limit the number of devices possible and finally decrease speed for
>all LVD devices. You can also get into all kinds of trouble.
>
>> The HP Specs do not mention the Scsi spec that the scannner allows, so
>> I'm only hoping that since it has the 50pin miniture Scsi2 connector,
>> that the scanner will provide the throughput of the Scsi2 specification
>> (10MB per sec).
>
>that's right, that's Fast SCSI 2.
>
>> Fyi:
>> Connector Type or Name: HD50 High Density 50-Pin
>> Called Mini D50, MicroDB50, MiniDB50, most 8-Bit SCSI FAST (up to
>> 10MB/sec) host adapters use this "high density 50-pin" connector.
>> 50-pin HD50 connector is 1 3/8" (36mm) wide vs. 1 7/8" (47mm) wide for
>> a 68-pin HD68 connector. Used on SCSI-2 and SCSI-3 peripherals.
>
>the better way to do it is to get an internal cable with 50pin-50pin
>connectors (so-called HDC50). You'd better think twice if you might need
>some internal connectors for devices like streamer and so on in the future
>(however, such devices are getting pretty scarce nowadays, most come with
>68pin connectors for wide ultra/single-ended or wide ultra 2 (LVD)).
>
>But be careful: the cable length for that bus mustn't exceed 3m in total,
>that means you have to count the cable for the scanner as well.
>The second part you need is a 50pin to 50pin Sub-HD (HDC50 to HD50) slot
>bezel (you lose one PCI/ISA slot). The external cable you need has two HD50
>connectors. Check for the cable thickness - usually such cables need to be
>pretty thick for quality otherwise they are known to cause problems. AFAIK
>the scanner doesn't need to be terminated (might have auto-termination,
>mine is running flawlessly). Should you ever get some internal devices, you
>mustn't terminate them. Be also careful to not Y-connect the bus (meaning
>that you must connect the adaptor to the end of the internal cable).
>Interesting reading:
>http://www.ramelectronics.net/html/scsi_connecters.html
>
>HTH
>
>--
>mit freundlichen Grüßen/with kind regards
>Christian Dürrhauer, Institute of Geography, FU Berlin
>
>Little Golden Book That Never Made It: Dad's New Wife Robert