The Sinclair QL Forum

Hi,

Backplane, 2 or 3 way would do. Buffered or unbuffered.

Can pay by Paypal.
I'm in the UK.

Ian.

Ian,

I have some brand new MPlanes. They're buffered, allow everything to be powered off an AT or ATX PSU, and work with a QL or Aurora. Three expansion card positions.

They're £42 including shipping. If you're a QUANTA member you get 10% off.

Dave - you could do with adding a picture so Ian can decide if the mPlane is the right back plane for him - from memory they are in a 2 x 2 configuration, rather than a 4 x 1 (one of the slots is actually used to connect to the QL, so giving 3 expansion slots...)

*nods*

I'm not at home right now so I can't do it this second, but I will when I get back.

Not immediately, but in due course I will be doing a backplane designed for the QL2 which will be QL compatible, buffered, take ATX power, and be very high quality. It will be one computer then three expansions in a row, like QPlane. It will also have a case designed to go with it available separately.

Hi,

I found pics for the Mplane......but thats not exactly what I am looking for. I am looking for a backplane that can slot into a standard QL case, and without the use of ribbon cables to extend out or anything like that.

Actually, I'll design my own if there's nothing out there to suit. I can easily put something together in EaglePCB......and make them available for sale?

Anyone got any schematic details?.......I am assuming the unbuffered ones will just be straight through 1:1 all pins (maybe add a decoupling cap or two). For the buffered type I'll need some input.
I'm assuming there is no addressing necessary to the various daughter slots.

Being new to QL, and with the idea I'll be working on some hardware projects I figure I'll need a backplane so I can plug in a memory card floppy controller and a slot free for the project I'm about to start. So, I figure a straight through connector to a couple of male connectors.

I did originally assume unbuffered would be the way to go, but am I detecting that this can be hit or miss and perhaps the addition of some buffer IC's etc is the way to go for that extra reliability, and of course external power options.

Suggestions appreciated.

Ian.

IanJ wrote:Hi,

I found pics for the Mplane......but thats not exactly what I am looking for. I am looking for a backplane that can slot into a standard QL case, and without the use of ribbon cables to extend out or anything like that.

Actually, I'll design my own if there's nothing out there to suit. I can easily put something together in EaglePCB......and make them available for sale?

Anyone got any schematic details?.......I am assuming the unbuffered ones will just be straight through 1:1 all pins (maybe add a decoupling cap or two). For the buffered type I'll need some input.
I'm assuming there is no addressing necessary to the various daughter slots.

Being new to QL, and with the idea I'll be working on some hardware projects I figure I'll need a backplane so I can plug in a memory card floppy controller and a slot free for the project I'm about to start. So, I figure a straight through connector to a couple of male connectors.

I did originally assume unbuffered would be the way to go, but am I detecting that this can be hit or miss and perhaps the addition of some buffer IC's etc is the way to go for that extra reliability, and of course external power options.

Suggestions appreciated.

Ian.

Some of the early backplanes for the QLs in the 1980s were indeed unbuffered and somewhat unpredictable. I think that companies like Miracle, Sandy, JFC, Adman, CST and Simplex all did fairly simple unbuffered two way backplanes (essentially pin to pin as you said) which were really only intended for a disk interface and memory expansion card, which usually (not always!) worked OK. From memory, there might have been the odd terminating resistor or capacitor here or there, but no real buffering. I think, not sure, that the Simplex Q+2 had some onboard electronics, not sure if that was for buffering or not. Some of them had power supply connections of their own where the QL may not have been able to supply the power needed.

Then CST did something called a Q+4, a big black metal beast of an expansion cage which sat under the QL, had its own power supply, a short ribbon cable up to a small circuit board which sat in the QL expansion slot. I had one of these at one stage - it did actually work with multiple expansion cards, but was so big and clumsy I gave up on it in favour of a second networked QL, that's how much I disliked the Q+4, despite it being THE expander at the time.

More recent backplanes have included the QPlane from Qubbesoft, and MPlane from TF Services and possibly later this year from Dave at Sandy.

For multiple expansion card, you may need an onboard EPROM to fix a ROM initialisation bug in early ROMs (versions AH, PM and JM if I remember correctly), which caused the QL to only recognise the first card with any onboard software driver ROMs. It only affected expander cards with onboard software (disk interfaces, sound cards, etc), not memory expansions etc. QL ROM versions JS, MG and any other later ones like Minerva were not affected by this (I think...)

Pictures of many of these backplanes are on Rich Mellor's QL Wiki - http://www.rwapadventures.com/ql_wiki/i ... re&lang=en - you may be able to get an idea from the pictures of what each was like and how suitable for what you want to do, in case you stumble across any second-user hardware on ebay for example.

A QPlane was better suited to putting a QL in a tower case - have a look at http://www.rwapadventures.com/ql_wiki/i ... ne&lang=en

Good luck with your hardware projects - encouraging to hear that a lot of work is going on in this 30th year of the QL.

The problem with backplanes usually isn't just the backplanes themselves, but the poor quality of the signals from the QL. There's nothing a backplane can do to fix those problems - just prevent them from being aggravating.

Don't get cheap DIN41612 connectors - they're just not worth it.

I will be doing some kind of backplane solution with a 4-layer board and ATX power, later in the year. I have three far more complex and important projects to work on in the meantime. A backplane is desirable but given the slow sales of the Mplane I don't think there's that much demand for them, to be honest. I am far more likely to do a replacement QL mainboard that just takes all the original socketed components but has a much cleaner signal and power layout.

The QL2 will probably have 2x internal expansion, but at this stage that is just rampant speculation on my part..

IanJ wrote:

Being new to QL, and with the idea I'll be working on some hardware projects I figure I'll need a backplane so I can plug in a memory card floppy controller and a slot free for the project I'm about to start.

My quick solution to the same problem was to fit DIN41612 as shown...

Coo that is clever!

Ha, I like that one!

Solves the "my desk has never been wide enough for the QL" problem.

(Although it might not be ideal with respect to signal quality - But if it works, it's good enough)

Tobias