ZX-Uno General discussion

[Alcoholics Anonymous]

Currenty, consider buying a monitor, suitable for ZX-UNO, with support for all spectrum cores and models, including Pentagon.
I have a good offer for the BenQ FP93GX, but I do not know if it meets all the conditions for ZX-UNO support.

This russian page indicates, that it works well with zx-evo, but specs says it support only 60-76 Hz vertical referesh rate.
http://nedopc.com/zxevo/zxevo_supported_monitors.pdf
It's kind of urgent, so any advice would be very useful...

VGA monitors (and even more modern LCD panels) quite often have older electronics driving them for legacy signals. So the manufacturer might claim only 60Hz+ operation even if the electronics inside can handle lower refresh rates because the manufacturer can't be bothered.

If the manufacturer says 60+Hz then that's all you can know for sure without trying yourself. The pdf seems to show someone tried it but no name attached :-/ Buyer beware I guess.

[Pegaz]

A 19" TV / Monitor that works well is the LG Flatron M1917A. It has RF, composite video, SCART, S-Video and VGA inputs. It supports 50Hz vertical frequency via VGA. I have two and use it with my FPGA and real computers (Spectrum +3 and Atari 800XL).

https://www.cnet.com/products/lg-m1917a ... 19-lcd-tv/

Thanks, unfortunatelly I cant find him around for months, so i hope this Benq model should be good alternative, becosue iz has very similar specs than this LG model.
Whats your oppinion, about it ?

[Pegaz]

This russian page indicates, that it works well with zx-evo, but specs says it support only 60-76 Hz vertical referesh rate.
http://nedopc.com/zxevo/zxevo_supported_monitors.pdf
It's kind of urgent, so any advice would be very useful...

VGA monitors (and even more modern LCD panels) quite often have older electronics driving them for legacy signals. So the manufacturer might claim only 60Hz+ operation even if the electronics inside can handle lower refresh rates because the manufacturer can't be bothered.

If the manufacturer says 60+Hz then that's all you can know for sure without trying yourself. The pdf seems to show someone tried it but no name attached :-/ Buyer beware I guess.

Yes, that makes sense.
For example, in specifications the LG M1917a monitor has the similar vertical refresh rate, as well as mentioned BenQ model 56-75 Hz, but it works with 50 Hz, for sure.
I think it's worth a try, I'm tired of waiting for that specific model, and the price is real bargain, just 15 eur.

[desUBIKado]

Without testing it you risk it not being able to run at 50Hz vertical frequency, and that is imperative if you want to enjoy the ZX-Uno and the cores running on it.

[Pegaz]

Without testing it you risk it not being able to run at 50Hz vertical frequency, and that is imperative if you want to enjoy the ZX-Uno and the cores running on it.

Well yes, but its reported to work with zx-evo Spectrum clone, which really confuses me...

[Pegaz]

In the meantime, I found another candidate:
https://mobilespecs.net/monitor/BenQ/BenQ_T201Wa.html

I dont know much about him, but specs says Frequency sweep:Horizontal: 31-83 kHz, Vertical: 50-76 HzPassband:135 MHz
Maybe its a good one for zx-uno ?

[azesmbog]

Vertical: 50-76 Hz

The Pentagon has a frame rate of 48-49 Hz, not all monitors show even 50 Hz. So just try.
There is even a special utility for checking monitors.
Even monitors of the same model and lineup perform differently.
I have several monitors Samsung SyncMaster 940N - so they work after one (but mostly work . Heh, it will be necessary to check them with this utility)

[Pegaz]

Today I got another offer for the BenQ T705, almost in my neighborhood.
I hope I'll be able to try it in a few days, but according to specs, it seems promising:
https://mobilespecs.net/monitor/BenQ/BenQ_T705.html

[Pegaz]

Ok, I was trying to connect ZX-Uno+ with the BenQ T705 monitor (confirmed to work on ZX-UNO forum), but I don't get any picture at all.
I tested the monitor with a computer, working good, which means that the device and VGA cable are Ok.
In BIOS/Advanced I set the VGA/59.5 Hz, perform Hard Reset, but nothing happens, don't even have a message out of range, but only - No Signal.
I used Lan cable connected to RJ45 to VGA adapter, exactly like this:
https://www.aliexpress.com/item/1005002 ... d874924-45

I'm not sure that the Chinese RJ45 to VGA adapter is good with right pinout, but that's the only way to connect the monitor with ZX-Uno+, I know...
What am I doing wrong?

[desUBIKado]

Ok, I was trying to connect ZX-Uno+ with the BenQ T705
I'm not sure that the Chinese RJ45 to VGA adapter is good with right pinout, but that's the only way to connect the monitor with ZX-Uno+, I know...

https://www.antoniovillena.es/store/pro ... db9-addon/

[Pegaz]

Ok, I was trying to connect ZX-Uno+ with the BenQ T705
I'm not sure that the Chinese RJ45 to VGA adapter is good with right pinout, but that's the only way to connect the monitor with ZX-Uno+, I know...

https://www.antoniovillena.es/store/pro ... db9-addon/

Well, I've already made a SCART cable, so I will try this via RJ45 connector, people have already been made for ZX-UNO+
https://www.zxuno.com/forum/viewtopic.php?f=12&t=3988
This adapter over expansion port is also good solution, if I fail to made it myself.

[Pegaz]

Just finished VGA cable for ZX Uno+ and this is the result on the BENQ T705 monitor.
I already had a RJ45 connector with marked pinout from my SCART cable, which I directly connected to the VGA plug, with protoboard wires, without soldering.
All cores I tried, work, Spectrum 48k gives 50Hz, while 128k and the Pentagon, reports 49Hz, I hope this is ok.
The only downside is a slight ghosting (see the right vertical edge of Dan Dare pics), so maybe someone has an idea, how to get rid of it.
I did the double check of all pins, but this is the same RJ45 adapter from my scart cable, where I don't have that issue.
I will try to eliminate some potential causes, (Shielding from Interfernce, another VGA cable etc), but I appreciate any advice.
Here's a couple of pictures, from today's session:

[Alcoholics Anonymous]

All cores I tried, work, Spectrum 48k gives 50Hz, while 128k and the Pentagon, reports 49Hz, I hope this is ok.

Looks pretty good from pictures. The problem one would be the Pentagon since it has a 48.xHz frame rate, which your TV UI is rounding up to 49Hz. The 128K should be 50Hz as well but it's likely the UNO is running the 128K from the same clock as the 48K/Pentagon so that the cpu is effectively 3.5MHz rather than 3.54MHz. The slightly slower master clock will cause the frame rate to dip below 50Hz since there are more Ts in a frame.

[Pegaz]

All cores I tried, work, Spectrum 48k gives 50Hz, while 128k and the Pentagon, reports 49Hz, I hope this is ok.

Looks pretty good from pictures. The problem one would be the Pentagon since it has a 48.xHz frame rate, which your TV UI is rounding up to 49Hz. The 128K should be 50Hz as well but it's likely the UNO is running the 128K from the same clock as the 48K/Pentagon so that the cpu is effectively 3.5MHz rather than 3.54MHz. The slightly slower master clock will cause the frame rate to dip below 50Hz since there are more Ts in a frame.

Yes, it looks like that.
However, I didn't have any tearing, chopping etc, with any of Spectrum cores, animation was always perfectly smooth.
As for ghosting, I don't have it when I connected Windows PC to the monitor, so I still hope i could find a way to eliminate him.
After all, it's the same RJ45 adapter I used with scart cable, where I also don't have this issue.
What can I say, looks like a lot to the effect w've seen on Spectrum with CRT TVs, back in the day.
I want to have a realistic display, but not this level of realism.
Or maybe I just expect too much from 15 years old monitor...

[Alcoholics Anonymous]

However, I didn't have any tearing, chopping etc, with any of Spectrum cores, animation was always perfectly smooth.

You mean there is tearing and chopping on the UNO core but not the other spectrum cores? If so, I think you should look into what version of the vga driver you have in that version of the UNO core. I know that Miguel was implementing a frame buffer approach so that 50 Hz -> 60 Hz frame rate conversion could occur in the hardware. Then you eliminate the problem of the monitor being unable to sync to the correct frame rate but you also introduce new problems like tearing and chopping if the conversion is the simplest approach. If it's not the simplest then you introduce a few frames lag. I don't really know if he actually put it in there.

If there are filters in the vga out (capacitors in the signal lines) then I suppose that might explain ghosting. I don't know the details about the uno though so what I say should be qualified with a pinch of salt

[Pegaz]

Today I tried my Uno setup and adjusted cores with appropriate VGA versions.
Mostly works well, but I can't start three of them: NES, ZX81(VGA) and Lynx.
NES had sound, but there's no picture and the other two, gives only the black screen.
Tried various combinations with refresh rate and VGA/NTSC modes, but without success.
I also can't make TBBlue core to boot in VGA mode by default, I always have to press F2 and F3 to get a picture.
Finally managed to test the latest [mention]azesmbog[/mention] Spectrum test core with kempston fix and I can confirm that Robotics now works perfect.

[mention]Alcoholics Anonymous[/mention]
No, actually I dont have tearing with any Spectrum core, no matter which refresh rate I use.
I'm really not too much into hardware and not sure I understood your explanation about that filter.
Simply, I don't know how to check if there's that filter in the VGA out and how to eventually fix ghosting, caused by him.
I will try to test with different monitor and then at least I will know, whether ghosting is due to a bad cable or I need to blame this particular Benq model.
According to the picture I saw at the zxuno forum, with the same monitor, it seems that there is no ghosting at all...

[Pegaz]

Does anyone know exac pinout for the ZX-Uno+ expansion port ?
I'm trying to find him, but without success.
I would like to make a proper VGA connector and I just need pins for RGB, CSync, VSync and GND.

[Pegaz]

Another question if someone knows.
Is it possible on ZX-UNO to disable second AY chip (Turbo Sound) and then how to set AY chip from stereo to mono ?
Maybe I'm wrong, but I have noticed in Aufwiedersen Monty, that the first 5-6 seconds in main menu tune sounds somehow different, strange, it seems that few notes do not play properly.
On emulators, the sound in that first psychedelic part is more natural, like I remember on 128K machines...

[desUBIKado]

Another question if someone knows.
Is it possible on ZX-UNO to disable second AY chip (Turbo Sound) and then how to set AY chip from stereo to mono ?
Maybe I'm wrong, but I have noticed in Aufwiedersen Monty, that the first 5-6 seconds in main menu tune sounds somehow different, strange, it seems that few notes do not play properly.
On emulators, the sound in that first psychedelic part is more natural, like I remember on 128K machines...

To control the core at such a low level, the registers of the ZX-Uno are used.

You can find their definition and how to use them here (in spanish): https://www.zxuno.com/wiki/index.php/ZX ... _de_ZX-Uno

However, all their values can be comfortably modified with the .zxuc utility. which can be found in the Summer of '21 distribution.

[Pegaz]

Yesterday I tested Colecovision core on ZX-UNO+ with [mention]desUBIKado[/mention] package and came across a strange issue.
There are about 160 roms on the SD card image in the COLECO folder, but during browsing from the core itself, over 30 are missing.
One of them is Tournament Tennis, which we talked about a few days ago and which I wanted to try.
I also tried to add some more roms, but the core browser doesn't see them either.
Is there maybe a cfg file with a fixed list of games or is it something else ?
Also, I found a smaller amount of Coleco 64k roms in the MSX/ROM/COLECO folder but this is definitely not the list that Colecovison core browsing.
My question is, how do I see all the roms on the SD card and how to add new games when needed ?

[Pegaz]

I found it, the MENU.TXT file in the root folder contains a fixed list of games and needs to be edited, because its not fully updated with all roms on sd card.
I'll test this later, to see if it works ...

[desUBIKado]

I found it, the MENU.TXT file in the root folder contains a fixed list of games and needs to be edited, because its not fully updated with all roms on sd card.
I'll test this later, to see if it works ...

I got the collection of roms from this link posted by Fabio Belavenuto. Now that you said it, it's true that there are more roms than the ones listed in the MENU.TXT file. If you create and share a new version of the file that includes the missing games I could include it in a future Summer of '21 DLC 2.0. Thanks in advance.

[Pegaz]

I found it, the MENU.TXT file in the root folder contains a fixed list of games and needs to be edited, because its not fully updated with all roms on sd card.
I'll test this later, to see if it works ...

I got the collection of roms from this link posted by Fabio Belavenuto. Now that you said it, it's true that there are more roms than the ones listed in the MENU.TXT file. If you create and share a new version of the file that includes the missing games I could include it in a future Summer of '21 DLC 2.0. Thanks in advance.

Ok, the job is done, we now have a fully usable Colecovision collection on zx-uno.
The file list has been updated, removed some duplicates/non-working files and now contains about 150 titles.
I tested it with some games that could not be used before and everything works properly.
The updated MENU.TXT and the complete COLECO folder are attached here:
https://easyupload.io/b874oq
btw, I literally got hooked on this Turnament Tennis, the pro level is real fun.

[Pegaz]

When I bought the ZX-Uno at the beginning of the year, I didn't have many expectations, but today I can say that this great little device is still very much alive and kicking.
Thanks to the efforts of enthusiast who continue to work on it, we have far more than "just a good Spectrum core".
At the moment, besides the excellent Spectrum cores, which is still actively improved, we have a very faithful Amstrad CPC, MSX, BBC B, Oric, Atari 800, VIC20, SamCoupe, Acorn Atom, c64 / c16 / plus4, JupiterAce, TRS-80 implementation..., a total of about 30 cores, as well as consoles NES, SMS, Colecovision, Atari 2600, Vectrex ...
The Spectrum core is certainly the quality leader of all fpga devices, with more than 30 separate ROMs, including the great SE Basic from Chloe project and many others.
The latest achievement is the amazing ZX81/ZX80 core, ported from Mister fpga, with some additional improvements, which completes this impressive collection.
More details about this core can be found here:
http://retrowiki.es/viewtopic.php?f=110 ... 295448fbff
Apart from this, by installing special firmware, the zx-uno becomes a great Jamma machine, with a large number of classic arcade hits.
If we add to that the fantastic [mention]bob_fossil[/mention] LFN browser, which somehow launched all this avalanche, the impression is really extraordinary.

[andydansby]

I’ve had my ZX-Uno since it first came out. It still is one of my favorite machines. Since I’m in the USA, I have to use a Roku TV to accommodate for the PAL signal.

The machine keeps chumming along nicely and runs just about everything I throw at it.