ZX Spectrum Clone - ZX Sizif-512

[PeterJ]

I've sold a few bits and bobs recently, so my retro piggy bank was full enough for another purchase.

I saw that @Luzie had posted elsewhere about the ZX-Sizif, so decided to give it ago. It's apparently arriving today, so if anyone's interested I can post a few pictures and more details over the weekend.

https://github.com/UzixLS/zx-sizif-512



I wasn't sure if to post this on FPGA or Hardware, as it's based on a Complex Programmable Logic Device (CPLD) - If I sound like I know what I'm talking about, please rest assured I don't! It also has a real Z80 and AY Sound chip.

Main features are as follows:

Half-sized PCB for 48K rubber case
Pentagon, Spectrum 128, Spectrum 48 and Spectrum +3e modes
Altera EPM1270 CPLD
Real Z80 in 3.5MHz, 4.4MHz, 5.2MHz, 7MHz (no-wait turbo) and 14MHz (turbo with wait-states) modes
512K RAM
Real AY-3-8910 with switchable stereo ABC/ACB/mono output
Sega 6-button joystick input; Kempston/Sinclair modes
Integrated DivMMC and Z-Controller, 1x microSD socket
PAL and RGB video output (Sega Mini-DIN/9 connector)
Digital video output header for EGA monitors, VGA scandoublers, etc.
ULAplus
Mono covox (Pentagon standard)
SounDrive (4-channel stereo covox)
WiFi addon
Tape input via 3.5" jack and Bluetooth
9-12V power supply with any polarity
Reset and Magic buttons; header for power button

Mine comes with Bluetooth and WiFi and cost £125 from a UK seller.

Edited by PJ.

[spider]

I'd be interested in seeing a few more pics of it and perhaps screenshots of its menu/configuration. Knowledge is power as they say. Plus its always interesting to learn about all clones both old and new.

[Pobulous]

This sounds really decent and at a decent price - can you point us in the direction of the UK seller?

[PeterJ]

Hi @Pobulous,

It was a user called JimmyDeath on eBay.

https://www.ebay.co.uk/itm/185398840728 ... media=COPY

[Pobulous]

Hi @Pobulous,

It was a user called JimmyDeath on eBay.

https://www.ebay.co.uk/itm/185398840728 ... media=COPY

Ah, OK, I had hoped it was someone selling more than one.

[PeterJ]

He tends to list them quite regularly @Pobulous, so worth dropping him a message.

[PeterJ]

Slight delay in testing, as I need to go up into the loft to find my PS/2 keyboard (I don't want to pull apart one of my machines, though I will look for something in the future so I can use a Spectrum keyboard).

Anyway, it powers on:

Connected via the enclosed SCART.

[flatduckrecords]

Heheh, I had that on my watch list @PeterJ. I never really inteded to bid but I thought it looked really interesting.

Have you tried out any demos or programs that make use of the Pentagon timings or extra RAM yet? Oh how's the WiFi support as well, can you load over the network?

[PeterJ]

Hi @flatduckrecords,

As soon as I find my PS/2 keyboard I will do some more testing and come back to you.

You can apparently access sites and download via the Gopher protocol which I haven't used before.

[flatduckrecords]

As soon as I find my PS/2 keyboard I will do some more testing and come back to you.

Thanks! I'm only curious, so just if you happen to try those features anyway. Interested to hear how you get on with it generally as well.

You can apparently access sites and download via the Gopher protocol which I haven't used before.

Ah, cool. I think they are known as "gopher holes" but I've never looked into it (so to speak) myself!

[PeterJ]

A few photos from the Gopher browser. I was able to browse and download files.







There is also a ZXDB Downloader, which after some tweaks on Cloudflare works fine.

[PeterJ]

I was rather suspect of the Bluetooth module included with the Sizif, but thought I would give it a go with the ZXPlay app from @kolbeck on my Android mobile. It's very easy to find and link the Bluetooth device, and to my surprise every game I tried loaded perfectly. No volume issues in the slightest. Very impressed.

[PeterJ]

Can anyone suggest any titles that make use of Pentagon timings? Thanks

[azesmbog]

Can anyone suggest any titles that make use of Pentagon timings? Thanks

If you test timings - then all three main models - zx48 \ zx128 \ Pent

There is such a fpga computer eLeMeNt ZX
It has been posted on the forum several times.
So, here is his page,
https://sites.google.com/view/elementzx/download
at the very bottom of the archive (with a password , in which there are a lot of demos and tests (including mine)
You can test with anything, but for example, the most obvious is Escher's test demo
\SD20220420\eLeMeNt\TESTS\Echer\
for all three main models.
well, there are still a lot of tests and demos, under the Pentagon the most correct demo timings and the RAGE test, in the same place

[spider]

Good to see its alive and well.

I'd completely forgotten about the Gopher protocol, last time I heard this was many moons ago.

As long as its a Gopher and not a Gremlin I'm sure it will be fine.

I do like the neat look of the PCB though it fits really tidy it seems going from your picture in the very first post.

[azesmbog]

extension sound card

[PeterJ]

I did speak to the seller @azesmbog, but apparently the chips for the extension board are hard to come by.

Details are here:

https://github.com/UzixLS/zx-sizif-512-ext

[PeterJ]

@azesmbog,

Are these the results expected?

Thanks

[flatduckrecords]

A few photos from the Gopher browser. I was able to browse and download files.
[…]
There is also a ZXDB Downloader, which after some tweaks on Cloudflare works fine.

That's terrific. Nihirash's work is really interesting. (I was inspired to set up my own gopherhole at robertmorrison.me just now. Not much on there yet but I'll try to add some when I have time.) Thanks for sharing more pics!

[azesmbog]

Are these the results expected?

Yes, for each of the three models in the respective modes.

[PeterJ]

I was inspired to set up my own gopherhole at robertmorrison.me just now. Not much on there yet but I'll try to add some when I have time.

I'm connected!

[flatduckrecords]

Cool, thanks for connecting @PeterJ.

I've added a TAP file (just my silly Spectrum cleaning simulator from WOOT ’21) to see how downloading works.

The gopher syntax is:

Code: Select all

Tlabel<tab>path<tab>host<tab>port

Host and port can be ignored since the file is local, and I chose type 9 for binary file. So that gives:

Code: Select all

9ZX Repair      /zxrepair.tap

[zx64]

Is it the same gopher which was in the 90s?

[PeterJ]

Is it the same gopher which was in the 90s?

Yes, it is.

[radventure]

This looks really great! Anything else to report on how this board is working out? Is this being used as a "day-to-day" Speccy?