[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Working towards something good*
In <45e502d7$0$91156$c30e37c6@lon-reader.news.telstra.net> Tristan
Mumford wrote:
> Polymorph wrote:
>
>> Michael is correct. Usually your motherboard will come with an
>> expansion bracket to plug into the header.
>>
>> If you want to roll your own - I don't believe that there is a
>> standard header pin arrangement, but a common one (and one that I
>> recently used to create a null modem) is to have a header of 10 pins
>> (9 of which are important) in the following arrangement:
>>
>> 1 3 5 7 9
>> 2 4 6 8
>>
>> And you connect them to a DSUB-9 using the same pin numbering (ie.
>> pin 1 on the MB goes to pin 1 on the DSUB-9, etc)... cheers, -p
>
> Unfortunately there is no header on the board for a second serial port.
> It also only supports one floppy drive. It's some sort of IBM board.
> eBay cheapie. I got it to replace my more functionally diverse but
> very sick older computer. The whole time I had the old computer it
> never had a fdd or hdd controller. I found the board in the computer
> building holiday cleanout garbage stack. I used an ISA SCSI controller
> in it instead.
>
> Anyway, back to the point. Thankyou for providing the pinout though.
> It was very nice of you. However I believe the standard configuration
> is a little different to that. Remember that the header numbering is
> in columns and the connector is labelled in rows. So... Header
>
> 2 4 6 8 10
> 1 3 5 7 9
>
> D9
>
> 1 2 3 4 5
> 6 7 8 9
>
> Header to D9
>
> 1 3 5 7 9
> 2 4 6 8
>
> (10 is NC).
>
> I may be wrong on this but I thought that was the way it normally was.
> D25 wires up nicely too, but not quite as sequential as that. I
> actually butchered a PC one a couple of days ago to make a male D25
> SSC connector.
"The nice thing about standards is that you have so many to choose from.
"
The connections are interleaved when an IDC D connector is used on the
end, but back in the day of cheap PCs with multi-I/O cards they often
used solder bucket D connectors. Presumably the labour cost to hand
solder them was cheaper than the extra cost of an IDC connector.
The soldered cables were often wired pin to pin i.e. pin 1 to pin 1, 2
to 2 etc. I found that out when I went to reuse an old internal serial
cable on a PC with only one serial port connector fitted!
--
* Roger Johnstone, Invercargill, New Zealand -> http://roger.geek.nz
* PS/2 Mouse Adapter for vintage Apple II or Mac
* SCART RGB video cable for Apple IIGS