Ethernet for the QL

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Pr0f
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Re: Ethernet for the QL

Postby Pr0f » Tue Jan 05, 2021 3:33 pm

There is that - although the computer it would be plugged into is largely full of obsolete and increasingly hard to find parts too ;-)

It is available in a PLCC package which makes it easier to accommodate on a smaller board - it was used in the Atari ST machines so there is a fair bit of old stock around.


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Peter
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Re: Ethernet for the QL

Postby Peter » Tue Jan 05, 2021 3:55 pm

Pr0f wrote:It is available in a PLCC package which makes it easier to accommodate on a smaller board - it was used in the Atari ST machines so there is a fair bit of old stock around.

That sounds better than DIL and would allow a solution without PLD - probably an advantage for tinkerers. The driver changes to initialize and use this chip has to be compared with the driver changes to get rid of highres timer dependencies - hard to say what costs more time.

What do you think about the overall system? How could this be combined with (S)GC? Derek mentioned the mini backplane, but wouldn't it be hard to bring out the network connector? Ethernet cable plugged inside the case does not seem nice.


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Pr0f
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Re: Ethernet for the QL

Postby Pr0f » Wed Jan 06, 2021 7:23 am

does the mini backplane flip the top board that comes out from the QL - I know it flips the board that would be entirely within the case?

The network socket could come out of the side - and using the backplane would add about an inch of length to the size of board coming out from the QL expansion port.


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Peter
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Re: Ethernet for the QL

Postby Peter » Wed Jan 06, 2021 8:57 am

Pr0f wrote:does the mini backplane flip the top board that comes out from the QL - I know it flips the board that would be entirely within the case?

Maybe Dave or Derek can answer this. From the routing issues involved, I think it's likely that the outer board is not flipped by the mini backplane.
Which makes it difficult to design a board that does not collide with (S)GC components. It would need cutouts - and those cutouts would not even be the same for both GC and SGC. Looking at the picture below, I'm not even sure that through-hole components would be possible at all on top of an (S)GC. Even the few mm of wires at the bottom of a board seem too much.

Mini Backplane2.jpg

Maybe the inner side of the mini backplane needs be used, and a cable like this to bring the signals out. Not nice, but cables hanging out somewhere was QL tradition for several extensions in the past...

ethernet_cable.jpg
ethernet_cable.jpg (8.67 KiB) Viewed 553 times


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Pr0f
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Re: Ethernet for the QL

Postby Pr0f » Wed Jan 06, 2021 9:21 am

Really need an edge on view or if someone has one of these backplanes, a pic showing another card plugged in on top...


Derek_Stewart
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Re: Ethernet for the QL

Postby Derek_Stewart » Wed Jan 06, 2021 3:09 pm

Hi,

Here are some photgraphs of the MiniBack Plane with Tetroid Gold Card in main expansion connector and a Qubide inteface in the connector facing over the QL board.

MiniBackPlane1.jpg

MiniBackPlane2.jpg

MiniBackPlane4.jpg

MiniBackPlane5.jpg


The Qubide board is raised up at on end due the IDE conne tor.

I do not think the upper connector above the QL Expansion port is usable


Regards,

Derek
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Pr0f
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Re: Ethernet for the QL

Postby Pr0f » Wed Jan 06, 2021 3:13 pm

that would only work with a non socket gold / super gold card version using SMT components - the disk controller could be swapped for one that doesn't need all the external passives too, and some board estate could be saved by using a large SRAM and not having to worry about the zip memory devices.


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Dave
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Re: Ethernet for the QL

Postby Dave » Fri Feb 19, 2021 7:27 am

The upper out facing port is usable with lower profile cards like the SQB, but no with the SGC etc. The in facing port is inverted.

I have none of these left but can whip up a batch if there’s enough interest.

I do like the idea of a Q68 compatible Ethernet card.

Could the VSYNC signal be used as a fast timer?


Derek_Stewart
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Re: Ethernet for the QL

Postby Derek_Stewart » Fri Feb 19, 2021 9:53 am

Dave wrote:The upper out facing port is usable with lower profile cards like the SQB, but no with the SGC etc. The in facing port is inverted.

I have none of these left but can whip up a batch if there’s enough interest.

I do like the idea of a Q68 compatible Ethernet card.

Could the VSYNC signal be used as a fast timer?

HI Dave,

I was going to get some PCBs made with the Gerber files you gave me.

I would only fit 3 connectors, leaving the top outer connector off the board due to height problems with the SGC.

But is there an benefit of having some sort of expansion header on the top outer connection?


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Derek
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Dave
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Re: Ethernet for the QL

Postby Dave » Fri Feb 19, 2021 11:24 am

I considered putting a ROM port there but the connector was chunky. I planned a set of short cards (6 cm) that would fit there including memory, IDE and etc. but me and plans aren’t friends....

I also particularly dislike the layout of the SGC. It works great but tries too hard to be small. If it were a little longer a different style of RAM could be used, and the overall height of the card would drop considerably. It could also trivially contain 4 or 8MB of RAM. That said, the logical design is ingenious.

If you’d like to make some Miniplanes, the design is 100% open. I do have all the parts. If you decide to proceed, let me know and I’ll send you some slightly updated files - a denounce cap or two, and termination on the RGB lines that prevents reflections going back to the DIN socket. Doesn’t make a visual difference but you can see it on an oscilloscope.

I do have a CP2200 QL card in my older libraries - it wasn’t great (my skills then were more raw) but it has never worked. I think it could be massaged into something workable. It could be very slim, with the Ethernet port passed out the ROM port. It could go beside the rom port but that involves case cutting, or sneak out the expansion port if there’s clearance.

It does seem a 120x100 card that clears the case and has a through port might be easiest.



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