Custom Williams Harness Project

D_Harris

Well-known member
Joined
Jan 27, 2008
Messages
2,518
Reaction score
51
Location
Staten Island, New York
I'm working on a custom wiring set-up and it requires that I extend the connection between a Robotron rom PCB and it's main board, because in my set-up the rom PCB has to be situated a couple of feet away.

I don't know how far away from the main PCB I can move the rom PCB without problems, but can anyone tell me the part number for the cable, which is at present about 4 inches long, so I can try to find out how long I can get them?

Or perhaps there is another option that will allow me to crimp my own cable if I can find the connectors at the ends.

Any help would be appreciated.

Thanks.

Darren Harris
Staten Island, New York.
 
Its a 40 pin dual row header, isnt it? Maybe you could use an old IDE hard drive cable, and use some long pins to join the two female connectors at the short cable???

I dont know how long you can get the cable without adversely affecting stability, but you should be able to handle the 18" IDE cable..
 
Its a 40 pin dual row header, isnt it? Maybe you could use an old IDE hard drive cable, and use some long pins to join the two female connectors at the short cable???

I dont know how long you can get the cable without adversely affecting stability, but you should be able to handle the 18" IDE cable..

The part of the ribbon cable that plugs into the main PCB also fits the IDE connector of a hard drive, but the other end that goes to the rom PCB is a different kind of connector. Finding out what connector this is would be a start.

(Ideally an option allowing me to use 20g -18g wires, from both connector types, instead of a ribbon cable would be great).

Thanks.

Darren Harris
Staten Island, New York.
 
I have asked this question a few times already myself. Why it is such a big secret beats me?

Anyway I can get you a little closer...

Search 42711 at jameco or 42712. These are for the ms. pac-man boards. I haven't looked yet but I bet they are close. If not the same keep trying the same number sucession like 42713, 42714 ect. Please post back if you figure out the correct connector. I really need to know this as well.

Possible Crimper # is 73252

Ribbon cable 10ft is #644113 $12.85
 
Solution is obvious... but it's more fun to chuckle than answer the question...

See what I mean it's got to be CIA or MIT Beautiful Mind Shit? I guess its a cable made at the fictious Wheeler Labs? It's all good secret squirrel or better yet Shults! I know nothing... Lmao lmao lmao

Today I get to pull out an awesome set of boards that Yd sold me and hook them up for the first time.

So I will be able to get a close up look at that pos cable after the boards being mothballed for three months.

Man it really must be something easy/stupid for Mark to post that above.

Deductive reasoning I say!
 
I'm working on a custom wiring set-up and it requires that I extend the connection between a Robotron rom PCB and it's main board, because in my set-up the rom PCB has to be situated a couple of feet away.

I don't know how far away from the main PCB I can move the rom PCB without problems, but can anyone tell me the part number for the cable, which is at present about 4 inches long, so I can try to find out how long I can get them?

Or perhaps there is another option that will allow me to crimp my own cable if I can find the connectors at the ends.

Any help would be appreciated.

Thanks.

Darren Harris
Staten Island, New York.

Darren, the length of transmission cable that it is possible to use depends on the cable types used, bus driver/receiver capabilities at either end of the cables and the speed of data being transmitted. for example bus driver/receivers with schmidt trigger inputs can work better with noisier signals than ordinary TTL devices.

If you remember parallel printers, you could use up to 5m cables reliably, providing the earth connections between the pc and printer were good, but the data rates were very low (what, up to 512kbit per sec ?). Data rates in an IDE connection are much higher (say 1-3Mbit per sec) and therefore useable cable lengths are much shorter.

(editted out text about SCSI cables)

The moral of the story is, if you use a long cable and have reliability problems or errors, shorten the cable (editted out text) &/or separate other cables from the long ribbon to minimise noise generated by proximity to other cables (whether mains, data or dc power).

Also, search on digikeys website for the manufacturer "CW Industries" for more details on the ribbon cables & connectors you are looking for (which bob roberts sells some versions thereof but not as much as digikey has in its catalogue!)
 
Last edited:
The part of the ribbon cable that plugs into the main PCB also fits the IDE connector of a hard drive, but the other end that goes to the rom PCB is a different kind of connector. Finding out what connector this is would be a start.

(Ideally an option allowing me to use 20g -18g wires, from both connector types, instead of a ribbon cable would be great).

Thanks.

Darren Harris
Staten Island, New York.

I found these once, have a couple in my stock; I could find them again if I had too BUT...

I have found that removing the plastic retainer from the top of the ROM board ribbon mount [without breaking the FRAGILE plastic clips that hold it together] and 'rolling' the old ribbon off followed by pressing [in a vice] a new IDE cable back on is best practice. If I can make it as far as removing the plastic clip without breaking the tabs, I have [thus far] 100% success.

Saltbreez
 
SCSI hard disk connections could run at higher data rates and with devices daisy chained together to make longer databusses, but, they used either passive or active termination to "pullup" or condition the databus signals.

I suggest you go read a primer on transmission line theory and learn what the termination resistors actually do before posting something so foolish again. =-P
 
I suggest you go read a primer on transmission line theory and learn what the termination resistors actually do before posting something so foolish again. =-P

Notwithstanding the fact that i was trying to illustrate issues with ribbon cable lengths in various contexts in a simple way, i have read such materials (a long time ago admittedly), including scsi bus technical information/termination theory, and worked with many scsi interfaces and peripherals, I have removed the questionable text from my post. I stand corrected.
 
I don't know how far away from the main PCB I can move the rom PCB without problems, but can anyone tell me the part number for the cable, which is at present about 4 inches long, so I can try to find out how long I can get them?
QUOTE]

Digikey www.Digikey.com sell connectors & made up cables that look correct - have a look at the connector specs pdf doco on catalogue page http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CPC40S-ND for the rom board connector.

I measured up the rom board connector on my Defender ROM board (Presumeably the same connector is used on the Robotron ROM board too.) and compared it to the CPC40S-ND connector. I used my Micrometer the check the pin spacing and sizes and the specs match.

There are also made up cables using those connectors - go to the home page http://www.digikey.com/ and search for "C3APS-4006G-ND" for a 6" cable, and "C3APS-4036G-ND" for a 36" cable (there are other sizes listed in the table http://dkc3.digikey.com/PDF/B092/P0036.pdf )

Can anyone confirm that the aforementioned Digikey "C3APS-4006G-ND" or similar cables are suitable for the Defender/Stargate/Robotron Rom to CPU board connections ?

Cheers.
 
Last edited:
I don't know how far away from the main PCB I can move the rom PCB without problems, but can anyone tell me the part number for the cable, which is at present about 4 inches long, so I can try to find out how long I can get them?
QUOTE]

Digikey www.Digikey.com sell connectors & made up cables that look correct - have a look at the connector specs pdf doco on catalogue page http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CPC40S-ND for the rom board connector.

I measured up the rom board connector on my Defender ROM board (Presumeably the same connector is used on the Robotron ROM board too.) and compared it to the CPC40S-ND connector. I used my Micrometer the check the pin spacing and sizes and the specs match.

There are also made up cables using those connectors - go to the home page http://www.digikey.com/ and search for "C3APS-4006G-ND" for a 6" cable, and "C3APS-4036G-ND" for a 36" cable (there are other sizes listed in the table http://dkc3.digikey.com/PDF/B092/P0036.pdf )

Can anyone confirm that the aforementioned Digikey "C3APS-4006G-ND" or similar cables are suitable for the Defender/Stargate/Robotron Rom to CPU board connections ?

Cheers.

Ok. The last post in this thread was a few days before my injury, surgery, complications, hospital stay, and all the other garbage that happened afterwards.

So I'm back to trying to figure out what I need and where to get it.

The following 40 pin cable should work between the main and rom PCBs:
http://www.digikey.com/product-detail/en/C3APS-4006G-ND/C3APS-4006G-ND/1123437

Then there is the 20 pin ribbon cable that should work between the main PCB and interface PCB:
http://www.digikey.com/product-detail/en/C3APS-2006G-ND/C3APS-2006G-ND/1123419

Now Bob Roberts sells the following:
Wms Ribbon Cable Main PCB to Rom PCB $9.50
Wms Ribbon Cable Main PCB to Interface PCB $8.50
Wms Ribbon Cable Main PCB to Speech PCB $9.50

Can anyone explain the need for a ribbon cable between the main and speech PCBs? (My boardsets do not have this).

Lastly, since I also need to crimp my own 40 pin IDE (and 20pin-whatever it is called) can someone tell me the search terms needed to find the connectors on Ebay and the tool needed to do this?

Thanks.

Darren Harris
Staten Island, New York.
 

Attachments

  • Williams Boardset.JPG
    Williams Boardset.JPG
    48.6 KB · Views: 6
Last edited:
Now Bob Roberts sells the following:
Wms Ribbon Cable Main PCB to Rom PCB $9.50
Wms Ribbon Cable Main PCB to Interface PCB $8.50
Wms Ribbon Cable Main PCB to Speech PCB $9.50

Can anyone explain the need for a ribbon cable between the main and speech PCBs? (My boardsets do not have this).

Thanks.

Darren Harris
Staten Island, New York.

i think that's for the defender/stargate/other williams boards, my boardset doesn't have that one either and it works perfectly fine.

(nope not defender i just checked my board).
 

Attachments

  • 100_1717.jpg
    100_1717.jpg
    100.4 KB · Views: 8
  • 100_1719.jpg
    100_1719.jpg
    100.3 KB · Views: 7
Last edited:
Back
Top Bottom