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Re: Discussion about connecting RASPI to QL

Posted: Wed Nov 29, 2017 11:36 am
by northernbob
Derek_Stewart wrote:Hi,

Is it possible to redirect the QL video signal to use he HDMI display of the Raspberry PI?

The Acorn use of the Raspberry PI on their Tube Interface has a custom operating system running. So maybe this will have to be written as well for the QL.

Sounds too hard...
2 have been written for the new spectrum, although one is partially finished. maybe these can be adapted for QL use?

Re: Discussion about connecting RASPI to QL

Posted: Wed Nov 29, 2017 11:43 am
by Pr0f
Looking at the speccynext web site, they moved away from using the Raspberry Pi to provide hdmi output, and now seem to have the hdmi connector directly on board and driven by the FPGA.

They still retain the 40 pin connector though, as the pi could be used for all sorts I guess...

There are some hurdles with hdmi - there are some open cores demonstrating basic video output on hdmi, but the technology is licensed out, so if you want to use ip cores from fpga vendors it gets expensive fast. The other issues are signal lengths, and board layout - there are some design requirements for hdmi, and cobbling together something that looks ok, may not actually work very when in practice.

I played around with the Terasic GX starter kit, which includes hdmi hardware - but beyond some basic video bars and patterns, it's a lot of work. I like my lego in bigger chunks :-)

Re: Discussion about connecting RASPI to QL

Posted: Wed Nov 29, 2017 1:14 pm
by XorA
northernbob wrote:is none here monitoring how the next project is going? surely this has a influence on the future of the QL ?
Probably 1/4 of the forum are, and waiting to see whether Q68 or Next lands in their mailbox next week first! :-D

Re: Discussion about connecting RASPI to QL

Posted: Wed Nov 29, 2017 2:15 pm
by Peter
northernbob wrote:is none here monitoring how the next project is going?
Yes I do, it would be funny if the cased Q68 is shipped even before the uncased Spectrum Next.

Compared to the Q68, which was designed by one person and no funds, the Next with a whole team and >700000 £ is a giant project.
northernbob wrote:surely this has a influence on the future of the QL ?
Maybe indirectly by keeping the Spectrum scene alive, and a few persons from there looking at the QL.

Technologically, I didn't see electronic aspects in the Spectrum Next that would be of interest for me. The best is the case! :D

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 8:46 am
by northernbob
ill resist, going into rant mode about the delays on the next, as am allegedly an adult now....

However it has been deeply frustrating to the gui grp. We really needed to test out the connection between the pi and the board.

atmo am living close to dave hoglett, who got the pi to accelerate the bbc master, so am gonna ply him with pints and persuade him to help us poor speecy munchkins out :mrgreen:
those beeb lads can be a bit aloof tho....makes me feel like a hobbit, entering into rivendell!

will see what happens)

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 9:52 am
by vanpeebles
northernbob wrote:those beeb lads can be a bit aloof tho....makes me feel like a hobbit, entering into rivendell!

will see what happens)
:lol: Brilliant! And accurate :lol:

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 10:54 am
by Peter
Do you think that the meaning of "beeb lads" is obvious on this forum? ;)

It took me a lot of guessing that "beeb" could mean "BeebEm" which is an emulator for a non-Sinclair, non QL-related, even 8 bit, homecomputer.
And I'm not sure I guessed right.

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 11:55 am
by Derek_Stewart
Hi Peter,

The Beeb is the Acorn BBC Micro.

There is an Acorn forum, stardot.org, which they are quite active in hardware design for the BBC Micro series, Electron, ARM PC.

When I get time, I will build a BBC B to Raspberry Pi link, they use a custom Raspberry PI operating system called Fake x86, which allows connection to the hardware linking the PI to the BBC B.

Looks like a lot of software development have been done, I doubt the QL could use this type of linking system. Due to the lack of software authors to write the hardware drivers on the QL.

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 11:58 am
by vanpeebles
It's a lot easier for BBCs as they have a proper Tube interface for co processors :D

Re: Discussion about connecting RASPI to QL

Posted: Thu Nov 30, 2017 12:41 pm
by XorA
vanpeebles wrote:It's a lot easier for BBCs as they have a proper Tube interface for co processors :D
Connected to a Pi though it really should be called the Choob interface :-D