Spectranet - ethernet for your Spectrum

[Gulliver]

I finally took the plunge and got a Spectranet ethernet adapter for my Sinclair Spectrums (I have a 48K "rubber devil" and a 128K toastrack these days)

I have to say, I am impressed. The unit worked right out of the box, connecting to the manufacturer's server which is pretty useful itself. Though I found Mark Round's site even better. And there's even Platoterm - a Plato terminal with access to much of the old Plato material from the 70s and 80s. I enjoyed playing Plato at battleships for the first time in 41 years.

The humble Speccy is online. I never once thought I'd hook up a Spectrum to the internet! There's even an irc chat client and a telnet client! But most of the pages designed for the spectrum are a bit of a cross between the old BBS and modern web pages. It's rather like surfing the web on your Spectrum.

[ortek_service]

I got one of those Spectranet assembled-PCB from the original Designer, Dylan Smith, (back in 2013 at the Silicon Dreams Computer-Show Weekend, held at Snibston Discovery Museum in Coalville, near Leicester) - Who I believe also gave a talk about it, (alongside Chris Smith's ZX Spectrum ULA Rev Eng talk & selling of the book Chris wrote describing the Spectrum ULA & the Rev-Eng process he used)

But I've never got round to trying it, so there might be some firmware updates since then. And I see you can now get cased versions: https://www.bytedelight.com/?page_id=3515
So I wonder if it's possible to buy a case, separately. Or can download a file to 3D-print one.

It's surprising that it's claimed to be about the only Spectrum Ethernet interface. I remember someone I know showing me the Spectrum PC ISA interface he'd designed & built on veroboard, that allowed him to connect an old PC Network card to it.But not sure how far he got, with creating software to support this, and I can't see anything about it on his website: https://www.mike-stirling.com/
But he was involved in the early days of reverse-engineering how parts of the ULA worked, to create an FPGA-based emulation of it.

[paulsherwin]

I've no personal experience of this, but I'd imagine implementing a TCP/IP protocol stack on a Spectrum would be more of a challenge than providing a raw packet level interface. An impressive achievement though.

[ortek_service]

Originally Posted by paulsherwin

I've no personal experience of this, but I'd imagine implementing a TCP/IP protocol stack on a Spectrum would be more of a challenge than providing a raw packet level interface. An impressive achievement though.

I think on this particular one, that much of this is handled by the interface board, being as well as the WIZnet iEthernet WS100 Ethernet 'PHY' interface, it also has these IC's:
Xilinx XC9572XL-TGC100 100pin TQFP FPGA +
AM29F010B-90 1Mbit FLASH and an
IDT71024S12YG 1Mbit 12ns SRAM

So may be a processor core running in the FPGA, with rather more computing power than the Spectrum's Z80, that this is off-loaded to and doesn't present much overhead to the Spectrum's Z80.

[cmjones01]

Yes, those Wiznet chips are really handy. They have the Ethernet interface and TCP/IP stack all built in, so the host microcomputer only has to say "open a socket to this address please" and it will. They make implementing internet applications on an 8-bit micro quite straightforward.

All the smarts on the Spectranet must be in the Wiznet chip. The XC9572 is a very old CPLD which doesn't contain much logic - just enough to make a few counters and gates, so it's probably used as glue logic, or maybe to create an SPI interface to talk to the Wiznet chip (though the W5100 has a parallel bus interface), as well as doing some bank switching to allow the RAM chip to be used (more memory comes in really handy when doing network stuff).

Chris

[Michael Haardt]

Originally Posted by paulsherwin

I've no personal experience of this, but I'd imagine implementing a TCP/IP protocol stack on a Spectrum would be more of a challenge than providing a raw packet level interface. An impressive achievement though.

The question is how minimal you want to go. uip and lwip have very different memory requirements, but both could work. See

https://github.com/adamdunkels/uip/b...uip-refman.pdf

for uip. You had to link the stack into the application, which means if the application ends, the system would not respond to a ping any more, much like NCSA telnet on DOS back then. uip needs an interrupt and a timer to handle timeouts.

Michael

[Gulliver]

I've spent some more time playing with the Spectranet on my 48K and 128K machines. Decided to set markround.com as the "home page" because not only does it contain thousands of games and demos from 1982 to the present day, it has quick links to Platoterm, and the Telnet client.

Another thing that has been *real* fun has been finding some BBS that I can Telnet to and registering for them on the Spectrum, even receiving email. There are a few multi user games though I haven't tried them yet. The software enables the Speccy to display full 80 column ANSI screens though the 128K definitely has a cleaner signal, making it much more easy to read the compressed text.

I think the case is available separately. I do thoroughly recommend this. It's currently sold in a few different models by Byte Delight of the Netherlands, they're currently in stock but I think they only make 50 at a time. I got mine uncased for just under £100 including post....delivery was about a week including a couple of days to process the order. There's the ability to download practically every Speccy game ever in secods direct to the original hardware, but also a whole world of Spectrum specific sites, BBS, irc chat, Plato.....I know you can do all these things from a web browser on a modern computer....but what fun to do it on a Spectrum.

Had some friends over recently who were absolutely blown away at this....we enjoyed a great retro gaming evening and I showed them Plato where some of the games and education material have copyright dates in the early 70s

[Gulliver]

And now I've hit a problem.

Virgin Media foisted a "hub 3" on me, to replace the hub 2 which was perfectly capable of functioning with every device I have.....laptops, phones, desktop PC, Raspberry Pi, Smart IR remote, Smart TV and the Spectrum

Guess what? Spectranet and the hub 3 don't get on. I am reading this might be something to do with something called UDP but there my knowledge ends.

Tried reinstalling the hub 2 with the intention of throwing 3 back at Virgin but it no longer wants to connect to anything

[ortek_service]

Well I didn't really know much about UDP either, but there seems to be quite a good description / comparison with TCP, here: https://www.avast.com/c-tcp-vs-udp-difference

I wonder if you can go into the config of your new Hub, and change back to / add TCP protocol? As I imagine many things might not work with UDP.
And if other providers go that way, for higher speeds?, then just ditching Virgin and going to a more universal FTTC / FTTP VSDL connection may not help for too long.

[Gulliver]

I gather UDP is used a lot in the gaming community and it's necessary for the fast data transfer for online games.

Problem is none of the workarounds suggested for gaming is working with my setup. Its a pain as I literally just dropped £100 on the Spectranet last month and I'd kind of like to use it. Having the Spectrum online was amazing and I'd only just begun to explore the possibilities.

[Michael Haardt]

Does connectivity between the Spectrum and other computers on your LAN work? Does the Spectrum use DHCP or a statically assigned address? That's where I suggest to start.

Michael

[Gulliver]

It can do either, there's a set up menu in the special ROM. By default it's DHCP but one can manually enter an address too. Currently it is assigning a valid IP but it's not mounting any sites.

I've no idea about connectivity between the Spectrum and other computers on the LAN. how might I go about achieving that?

[Phil__G]

Step one is can you ping your router?

[Gulliver]

I just pinged my router from a laptop connected to it's wifi.

4ms average

[Mark1960]

I think Phil was asking if you could ping the router from the spectrum.

[Gulliver]

Originally Posted by Mark1960

I think Phil was asking if you could ping the router from the spectrum.

Ah that makes more sense, but I don't think there's a way of doing that even when it is all working.

Basically it's successfully getting an IP address but won't do anything else. All since I installed the Hub 3. Reading elsewhere there seems to be a popular opinion that this hub is junk, but the Hub 2 no longer wants to work.

[SiriusHardware]

Even if the old router no longer gets an internet connection it should still be possible to connect to its configuration interface using a browser to look through and note down its configuration settings.

If you then do the same with your new browser you may see some settings which are different - possibly the new one may be more locked-down than the old one, or it may present a 'nanny interface' to any new device which connects to it (do you want to turn on child lock / block adult content etc) which you can't see through the Spectrum's interface to the web.

[Phil__G]

Originally Posted by Gulliver

Ah that makes more sense, but I don't think there's a way of doing that even when it is all working.

In that case can you ping the Spectrum from any other device that is connected to the router?
Can you see the spectrum in the routers dhcp list and its interface stats?

[Gulliver]

Originally Posted by Phil__G

In that case can you ping the Spectrum from any other device that is connected to the router?
Can you see the spectrum in the routers dhcp list and its interface stats?

It shows up in the list of connected devices when I go into the router's advanced settings. It's obtaining an IP address successfully but that's it. With the hub 2 it worked without any settings being fiddled with.

[SiriusHardware]

1) Tell your ISP that the hub 3 has broken part of what you need to do on the internet and ask them to disable the hub 3 and re-enable the hub 2.

2) Look through the settings of the hub 2, which should still be working as a self contained unit (just not connecting to the internet) to see if there is anything set there which you can change to or mimic in the settings of the hub 3.

3) If your (smart) phone, assuming you have one, is able to act as a wifi hotspot and connection to the internet, try using that.