On the SCSI pins.

The reason they are 1, 2,  and 4 is for you to come up with an ID from 1-7.

So no jumper = 0
Jump 1 = 1
Jump only 2 = 2
Jump 4 = 4
Jump 1 & 2 = 3
Jump 1 & 4 = 5
Jump 2 & 4 = 6
Jump 1, 2 & 4 = 7

HTH
Blair

Changhsu Liu wrote:

> I'm changing my internal Panasonic 7502b to an external one. One thing I
> cannot figure out is to set up jumper of SCSI ID so that the SCSI ID can be
> set from the switch outside the box.
>
> By reading the simple instruction comes with the external case, it seems
> that I should put:
> RED to pin1,
> BLUE to pin2,
> YELLOW to pin4, and
> BLACK to COM.
>
> >From Panasonic jumper info:
> 1 to 3 for scsi ID control,
> pin4 : parity,
> pin5: no pin,
> pin6: terminator,
> pin7: term power.
>
> Result:
> Since I took pin 1 to 3 out and put the corresponding connectors in, my
> computer recognize it as SCSI "0" no matter what number on my switcher.
>
> Here are my questions:
> 1) I can find corresponding pins for red, blue, and yellow lines from the
> back of panasonic, but where do I put the BLACK one, Which pin is COM?
>
> 2) Each jumper pin in the back of panasonic has 2 pins (top and bottom),
> but the lines for each pin ID from the external case has only one
> connector. Do I connect the top one or the bottom one? (I have tried on
> both but it didn't make any difference. The SCSI ID number cannot be
> controlled by ID switch.)
>
> 3) What are the functions of jumpers on pin 6 (terminator) and pin 7 (term
> power)? When pin6 is ON, does it mean it's internally terminated that I do
> not need a terminator if my drive is on the last of the scsi chain?
>
> 4) From the back of the panasonic, I can see numbers 1, 2, 4 on the
> location of pin1, pin2, pin3. Why do they call pin3 "4"? The number does
> match the description in the instruction of the external case. There must
> be a reason for the number being "4" instead of "3", but why?
>
> 5) Is there a restriction on the scsi number you can use on PC? I know "7"
> is reserved for system for Mac. Is it the same with PC?
>
> Thanks for the help,
>
> Changhsu Liu
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>
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