ZX Spectrum Next (and compatibles) QL Core now available!

[lliont]

I have written my own fat routines but they are written in Lion CPU assembly language, have no problem with fragmentation also.

[lliont]

[...] after all I made the mouse driver for QLion by studing your code.

Hopefully you didn't study my initialisation code though. It contains unclean timing loops und seems overly picky with mice. Deserves a total rewrite. But my LRESPR driver is okay.

No just the lrespr, the mouse initialization is done in hardware in my cores.

[martyn_hill]

Hi everyone!

On a slightly tangential note, I thought to share the schematic of the small and simple hardware adapter that will be needed to attach the Next via its JOY1 port to the QL/ZX Network. The latest driver is v1.03 - so look for that on the SpecNext site in due course (I only just finished updating it a couple of hours ago...)

The 'mechanics' of the Joy2NET adapter need some further thought, but my first version worked perfectly well on a breadboard, so anyone should be able to assemble something fitting

In the two attached schematics, the items in green represent the components needed in the adapter - the pink items are just there to highlight the relevant differences inside the KS1 and KS2 machines JOY1 ports to which the (same) adapter connects.

Below is a small write-up I made for the Crash Live event that summarises the NET driver (NDNxt) for Leon's awesome QL-Core on the Next, along with reference to the Joy2NET adapter design.

Have fun!

We are pleased to announce a new Networking solution for both the KS1 and KS2 Spectrum Next running the latest QL-Core!

The Sinclair Network-Driver software (ND-Nxt) plus an adapter (Joy2NET) allow connection of your Next to both the QL as well as the ZX Spectrum+Interface-1 at around 90 kbps - without the need to purchase and attach an Interface-1 to the Next itself.
Connection to a Sinclair Network allows for simple transfer of files between legacy Sinclair machines and the Next, as well as the possibility of new network-based multi-player games!
Connection is made via cheap and robust 2-core cabling, with simple 3.5mm mono self-terminating jack-sockets - and with none of the cost and complexity of the cabling typically required by serial-port and other network technologies of the era.
Tony Tebby's Toolkit-2 File-server/client is fully supported between the Next's QL-Core and other QLs, further simplifying file-transfer and other advanced NET-RPC type functions.
The ND-Nxt driver is a new port of the ND-Q68 driver previously developed for the excellent Q68 FPGA-based QL - both drivers include 80%+ of Tony Tebby's original Sinclair Network code and the efficacy and simplicity of Sinclair's low-cost network solution is a tribute to TT and Sinclair Research ltd's original design!
A native ZXNextOS NET driver is also planned to be developed to run in the Next's default 'personality', further enhancing connectivity options for Next users.
The simple adapter required to connect the Next to the Sinclair Network can be built using readily available components for less than £10.
The Joy2NET adapter design and the ND-Nxt driver software/source will be made freely available for anyone to further adapt and develop.

[Peter]

Hi Martyn,

has either JOY_P7 or JOY_P9 direct connection to an FPGA I/O pin?
In that case, the much simpler Q68 circuit could probably be used.
Leaving only the 3.5 mm jacks, a schottky diode (e.g. BAT43), one 47 Ω and two 330 Ω resistors.

Leon just needs to make some simple FPGA changes.

All the best
Peter

[Derek_Stewart]

The QL NET adapter I make for the Q68 is a cable with the diode and resistors soldered inline and insulated.

The Next QL adapter might need a case , but I have not got KS2 Next.

Just have stick to the Q68, at least I have SMSQ/E, high resolution, 2 SD Card readers.

[martyn_hill]

Hi Peter!

has either JOY_P7 or JOY_P9 direct connection to an FPGA I/O pin?

They are actually buffered via a HC157 mux.

Unfortunately, a simpler arrangement like you suggest didn't work due to how the Joystick ports are wired on the Next with an active pull-up on Input pin-9 and, in order to ensure the voltage and current drive (c24mA) of the original Net spec, it was necessary to provide additional drive from the HC157 at the output.

This was the simplest configuration/number of components I could devise after a number of iterations and testing, though I'd welcome further ideas/refinements!

[Peter]

Thanks for the explanation, I have no schematics of the Spectrum Next, hence no further ideas.

[QuantumLeapGR]

Thanks for the explanation, I have no schematics of the Spectrum Next, hence no further ideas.

Next schematics are freely available so people can make clones; here they are: https://gitlab.com/thesmog358/tbblue/-/ ... type=heads

[Peter]

Thanks for the link. For me, the main point of the Spectrum Next is the beautiful case, so I wouldn't use an external PS/2 keyboard.
The PS2_DATA line could then be used for a much more primitive network interface with just the termination resistors and a 47 Ohms series resistor.
(The 4.7 K Pullup causes only a neglegible 0.03V distortion of the low level on the network line.)

(On the video, Martyn seemed to struggle a lot with the Spectrum Next keyboard, can that be resolved? Or does the QL usage call for an external PS/2 keyboard?)

[QuantumLeapGR]

Thanks for the link. For me, the main point of the Spectrum Next is the beautiful case, so I wouldn't use an external PS/2 keyboard.
The PS2_DATA line could then be used for a much more primitive network interface with just the termination resistors and a 47 Ohms series resistor.
(The 4.7 K Pullup causes only a neglegible 0.03V distortion of the low level on the network line.)

(On the video, Martyn seemed to struggle a lot with the Spectrum Next keyboard, can that be resolved? Or does the QL usage call for an external PS/2 keyboard?)

I don't know which core version he was using there but it's quite natural once you get used to it after 10-15 minutes; Originally it was a bit of a pain but thanks to suggestions by Simon and excellent work by Leon it's now very natural. CTRL and ALT are on GRAPH and EXTEND which may be on different rows but are in the right location laterally.
I find it very easy to use tbh.
The PS/2 connector is dual obviously so it can accomodate both keyboard AND mouse. The Joystick solution especially given that the Next has CTCs similar to Q68s makes it ideal to realise martyn's driver/interface combo on both sides.

Of course the core is open source; you could make it run on the Q68 (which would be great fun I think)