Looking for IC piggyback adapter

[+x=usr(1536)]

Not knowing the name of what I'm looking for (assuming it exists), the searching I've been doing has not been turning up the sort of results I'm looking for.

 

What I would like to find is a device specifically designed to allow for piggybacking two ICs of the same type into a single socket - in other words, a splitter of sorts.  It could be two identical sockets on a PCB; it could be a ribbon cable plugged into the appropriate socket on the PCB that allows for the connection of two like ICs to it.  The idea is that it would eliminate the need to solder directly onto a socketed IC in the PCB in order to accomplish the same thing.

 

Does anyone know a source for such a thing, or what it may be called?

[+Stephen Moss]

I seem to recall someone asking a similar question a year or two ago to which no solution was forthcoming.

 

I am not sure as to why you would want to do that but generally Piggybacking is a lazy idea, not a good idea.

For example piggybacking a good IC on top of a potentially bad one to try and ascertain if it is in fact bad my prove inconclusive, particularly if the fault is an I/O pin shorted to GND or VCC as the good pin may not be able to over come that so not only will you see no improvement in operation, but potentially the excessive power draw from the good chip as it struggle to overcome a potential fault could result in damage to the respective I/O pin of the good IC.

 

If the devices have tristate outputs and you manually switch the chip select lines so they don't interfere with each other (one only active at a time) that may show some positive result, even then if the problem lies with an input pin it may not as you are only isolating the output pins.     

 

[+x=usr(1536)]

5 hours ago, Stephen Moss said:

I seem to recall someone asking a similar question a year or two ago to which no solution was forthcoming.

That may have been me; this has been bugging me for a while.

Quote

 

I am not sure as to why you would want to do that but generally Piggybacking is a lazy idea, not a good idea.

Agreed, but in this particular instance it's normal practice.  The scenario I have in mind is attaching a UAV to the back of a 4050 in order to maintain RF output after the UAV is installed.  Ideally this could be done in a way that keeps everything socketed so that it's easily-reversible.

 

With a redesign of the UAV this would also be possible while keeping close to the original footprint.  However, that involves a redesign of the UAV

 

And yep, I'm aware that 4050s are cheap.  This is intended to make taking an all-in-one approach to the installation feasible.

[+-^CrossBow^-]

3 hours ago, x=usr(1536) said:

Agreed, but in this particular instance it's normal practice.  The scenario I have in mind is attaching a UAV to the back of a 4050 in order to maintain RF output after the UAV is installed.  Ideally this could be done in a way that keeps everything socketed so that it's easily-reversible.

What are you installing a UAV into that would ever disable the RF output? The only instance of this would be possibly on the 5200 if you remove the 4050 from circuit. But I've been installing the sockets on top of the 4050 for the past 2 years now in my installs just so I don't have to remove it from the circuit. I actually came up with some ideas on redesigning the UAV that would only have extended it a tiny bit to allow for a 4050 to be soldered into place in addition to the interconnects and submitted the ideas to TBA but not much came from it I'm afraid. In fact, the chroma fix on the 7800s could be implemented onto the UAV directly in a similar fashion.

 

Not sure how widely this is known, but before TBA took over the UAV, Bryan was planning to redesign it to include a 4050 already in place using an SMD version so that the originals could be removed to plug the UAVs into their place and still have a 4050 in circuit to keep the RF functional along with making the installs more concise on the process to doing them.

[+x=usr(1536)]

20 hours ago, -^CrossBow^- said:

What are you installing a UAV into that would ever disable the RF output? The only instance of this would be possibly on the 5200 if you remove the 4050 from circuit.

Both my 800XL and 1200XL required removing the 4050.  Granted, I am that weirdo who likes to retain RF shields whenever possible, but the idea I'm proposing should shave enough height compared to a socket on the back of the 4050 to keep that possibility open.

 

20 hours ago, -^CrossBow^- said:

I actually came up with some ideas on redesigning the UAV that would only have extended it a tiny bit to allow for a 4050 to be soldered into place in addition to the interconnects and submitted the ideas to TBA but not much came from it I'm afraid.

I had a similar idea, but it would involve a redesign of the UAV board and not a terribly minor one.  Basically, replace the existing jumper block with a pair of rotary-dial switches, move them to a different part of the board (which may require extending it in at least one dimension), and use the area currently occupied by the jumpers for a socket / direct attachment to the PCB.

20 hours ago, -^CrossBow^- said:

In fact, the chroma fix on the 7800s could be implemented onto the UAV directly in a similar fashion.

That's something that would be absolutely terrific to see.

20 hours ago, -^CrossBow^- said:

Not sure how widely this is known, but before TBA took over the UAV, Bryan was planning to redesign it to include a 4050 already in place using an SMD version so that the originals could be removed to plug the UAVs into their place and still have a 4050 in circuit to keep the RF functional along with making the installs more concise on the process to doing them.

SMD would definitely be the way to go to keep the profile as low as possible, and would open up the possibility of keeping the same PCB dimensions while using the rotary dial switches to select the machine in use.

[+-^CrossBow^-]

22 minutes ago, x=usr(1536) said:

Both my 800XL and 1200XL required removing the 4050.  Granted, I am that weirdo who likes to retain RF shields whenever possible, but the idea I'm proposing should shave enough height compared to a socket on the back of the 4050 to keep that possibility open.

I did the socket solder onto the 4050 when I did my 130xe to keep the RF functional. I then used my dremel to cut out the opening in the RF shielding to allow the for the UAV to come through. Actually works out better this way because I can more easily adjust the trimmer with the composite output to tune in the artifacting without removing the keyboard and RF shield.

 

[+x=usr(1536)]

21 minutes ago, -^CrossBow^- said:

I did the socket solder onto the 4050 when I did my 130xe to keep the RF functional. I then used my dremel to cut out the opening in the RF shielding to allow the for the UAV to come through. Actually works out better this way because I can more easily adjust the trimmer with the composite output to tune in the artifacting without removing the keyboard and RF shield.

Understood ?  I'm just trying to keep the RF shields as unmodified as possible - if they're 100% intact, they're useful for otherwise-stock machines that are missing them.

 

Believe me, I completely realise that this is entirely my own weird little thing going on.