Author Topic: CPC Bus Extension  (Read 757 times)

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Offline rpalmer

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CPC Bus Extension
« on: 06:15, 06 August 17 »
Hello People,

I have had no luck getting my internal disk drive working (suspect the Disk Controller is the issue, reads directory but wont do much else... really annoying me).

To that end I have been thinking outside the box (so to speak) and decided to create an bus extension board as first step to overcoming this issue.
The bus extension board is very simple and has same connectors as used by Mx4, but of course nothing else (no reset or power port for external power supply). The CPC users should be able use the board in much the same way the MX4 is used. The exception here is of course is with those boards which may need additional power. The power issue is also being catered with development of a small PCB to have such and a reset button to sit between the bus extension board the CPC connection (more on this later in this thread).

People might say why not put it all onto the one board, well this is to make the build as simple possible with minimal component types (there are just 2 see attached photo of it) and to not simply be another Mx4.

The PCB is single sided and the Eagle file is attached for those who would like to build their own. I have one spare empty PCB made by PCB Pool (aka Beta Layout).

As mentioned above this is the first step. There are two other boards in the build process (a SPI interface and the updated 2Mb memory expansion). The SPI interface will have its own thread shortly and the 2Mb memory thread will also be updated as well.

rpalmer

Offline zhulien

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Re: CPC Bus Extension
« Reply #1 on: 16:14, 06 August 17 »
nice!  will it connect to CPC with small ribbon?  I am guessing from the connectors on it, they can be chained?

What's the prices of these? Also will you have adapters for behind as well to connect other CPC stuff?

As a side note... what would be the cost if you could create a bex8 also, instead of 4 in a row, is 4 side by side alternating slightly?

eg:

   HH
----
     ----
----
     ----
----
     ----
----
     ----
   HH
CPCGOES HERE

Of course pure side by side means the bex would have to be super wide so the cards don't bump into eachother, but if they are kind of staggered, you only need to make the bex a little deeper, but also not so wide. 

My current solution is to have the 2nd mx4 connected to the first, but the 2nd is connected with a very long ribbon that can neatly fold to make the 2nd mx4 90 degrees to the right.  As it is still behind the first mx4, it still is very deep into the desk.

Perhaps 2 bex4's behind eachother could work if the first is using a long ribbon to put both connected units to the side of the CPC?

What's your thoughts?
« Last Edit: 16:21, 06 August 17 by zhulien »

Offline rpalmer

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Re: CPC Bus Extension
« Reply #2 on: 00:06, 07 August 17 »
The board is connected with the same cable as used with the MX4. For me I have created an adapter to connect to back of the CPC so that a simple ribbon cable with IDC connector on each can be used.

I could easily make it a 6 slot version and even an 8 slot version, but the more slots the more power is used by all cards inserted which my be a problem.

Other options for the Bx4 are on the cards. so any other suggestion are welcome such as a right angle adapter so another Bx4 board can be connected.

As for prices I have yet to work out those details yet.

rpalmer

Offline rpalmer

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Re: CPC Bus Extension
« Reply #3 on: 03:18, 16 September 17 »
Hello People,

I have more BEx4 PCBs available to now build up to:

a. 4 Right Angle adapters - New
b. 4 BEx4 Adapters
c. 20 connector cards (these connect the adapters together) - New

As you can see from the pictures below you can use multiple cards get more sockets to connect more cards  8) .

The right angle adapter will have a power socket and reset button. The attached picture shows they are not there yet as I don't have those bits to complete the build.

I can take pre-orders via PM and will finalise the costs in the coming days. If there are more than what I can build right now I will order another batch of PCBs (these take about 2 weeks).
If people want it as a kit to build (or just the PCB), I can supply that as well.

rpalmer

Online LambdaMikel

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Re: CPC Bus Extension
« Reply #4 on: 07:46, 16 September 17 »
Nice! Have you tried which expansions are still working half a meter aways from the CPC?  ;)

Offline ||C|-|E||

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Re: CPC Bus Extension
« Reply #5 on: 15:19, 16 September 17 »
Definitely interested on this!  :) The right angle adapter is going to be really useful in my case, hehe
« Last Edit: 15:29, 16 September 17 by ||C|-|E|| »