(colour) CRTs have a pixel mask to produce red, green and blue from a single electronic beam. On a CRT there is no such thing as a sharp pixel. When you compare the same picture on a CRT and a LCD, you will see, that the picture on the CRT is much more blurry - but also smoother. It's personal preference if you like one more or the other. Or you don't bother. But some people would never replace their beloved CRT for an LCD, just because of the pixel mask.
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| [[File:ModernLCD AsphaltCRT.JPG|thumbnail|none|Pixel mask of a CRT]] || [[File:ModernLCD AsphaltLCD.JPG|thumbnail|none|The same game on a LCD]]
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== How to connect to a modern LCD ==
The CPC monitor connector offers 3 lines for the colours red, green and blue, and one line for a composite sync (csync) signal, that combines horizontal and vertical sync. The horizontal frequency is 15.6Khz and the vertical frequency is 50Hz. In short: If your monitor supports RGB and these frequency values, you can use your monitor directlywith a simple, passive adapter. If not, you need a an active converter.
=== Direct connections - options without converters Options with passive adapters ===
==== LCD TV sets (SCART) ====
Many LCD TV sets offer a SCART connector, which often accepts the CPC signal directly. All you need is a [[TV SCART cable|CPC-to-Scart cable ]] that you can either build yourself, or buy on Ebay for not too much money. Especially if you wnt want a distinct monitor for your retro corner anyway, this can be a pretty nice and cheap solution. Used 15" camping TV sets have just the right size to feel comfortable and can be bought for a few bucks on Ebay or your local classifieds.
Your only enemy here is: screen lag. Some of the LCD TVs perform almost like CRTs, others seem to include a SCART2HDMI converter, and they have a bad lag (see below).
For most of them, all you need is to connect 5 pins of the CPCs 6pin DIN connector to the right pins of a VGA connector - and that's it.
{||-| [[File:CPCVGAconnectorPinouts.png|thumbnail|none|CPC and Plus to VGA - pinouts]]|| [[File:ModernLCD CPC2VGA1.JPG|thumbnail|none|CPC to VGA (female) adapter]] || [[File:ModernLCD CPC2VGA2.JPG|thumbnail|none|CPC to VGA cable]]|} A known example for a perfectly working monitor is the BENQ 702A. More examples can be found on the internet (see links below), but be aware, although the [https://pinoutguide.com/Video/VGAVesaDdc_pinout.shtml VGA standard should accept Csync on pin 13], some monitors expect separate v-sync and h-sync signals. In those cases, [[Connecting the CPC to a VGA monitor - CPC2VGA|an adapter, that splits c-sync into h-sync and v-sync (CPC2VGA)]] would be required.
A known example for a perfectly working monitor is the BENQ 702A. More examples can be found here, but be aware, although the [https://pinoutguide.com/Video/VGAVesaDdc_pinout.shtml VGA standard should accept Csync on pin 13], some monitors expect separate v-sync and h-sync signals. In those cases, an adapter, that splits c-sync into h-sync and v-sync would be required.
=== Converter options ===
There are plenty of active converters to connect retro computers and consoles to modern TVs and monitors. Their biggest difference is performance and price. And if you are not willing to do a bit of soldering, you probably will end up with either spending a lot of money - or getting a bad solution.
==== SCART to HDMI converters ====
tldr; DON'TSCART to HDMI converters are the cheapest and most simple solution. USEMake sure they (really) support RGB and not only composite video, like the cheapest SCART to HDMI converters usually do. THEMRGB SCART converters start at around 30€ (2022). They will usually work and you will probably first think, that this is perfect, but they can add a hefty lag to your screen, some add up to 120ms (or 6 frames).
SCART to HDMI converters are the cheapest and most simple solution. Make sure they (really) support RGB and not only composite video, like the cheapest SCART to HDMI converters usually do. RGB SCART converters start at around 30€ (2022). They will usually work and you will probably first think, that this is perfect, but they usually add a hefty lag to your screen, easily 120ms or 6 frames[[File:ModernLCD Scart2HDMI. JPG|thumbnail|none|Typical Scart2HDMI box]]
Avoid This Youtube video explains in detail why you should [https://youtu.be/7VOsOuQ5mhM?t=587 avoid Scart to HDMI converters for retro gaming]. It's fine if you only want to do a bit of BASIC programming or play adventures, but it's not good for could do some harm to fast action games.
==== Scan converters ====
===== GBS8200 (VGA) / HD-VC9900 (HDMI) =====
These converters have originally been made to convert signals of arcade boards to modern LCD monitors via VGA (GBS8200) or HDMI (VC9900). [[File:ModernLCD GBS8200GBSControl.JPG|thumbnail|none|GBS 8200 with GBS Control mod]] They do support the signal of the CPC but without any further modification, the conversion quality is limited. It adds up to 2 frames of lag, which might be just acceptable, but many famous games and demos won't work due to synching problems. All this improves a lot, once you add the GBS control mod to it. That's basically adding a microcontroller to the original board, that takes over control and adds features and flexibility that are [https://www.youtube.com/watch?v=fmfR0XI5czI&t=879s close to the Framemeister and OSSC]. Also the lag shrinks down to [https://www.youtube.com/watch?v=fmfR0XI5czI&t=783s less than a frame], at least if your monitor does not add much lag on top.
See [https://github.com/ramapcsx2/gbs-control GBS Control for GBS8200] and [https://github.com/ramapcsx2/gbs-control/issues/165 VC9900]
Especially the GBS8200 is easily available and incredibly cheap and if you know how to solder, the GBS Control mod is easy to do. And that's of course also the downside: you need to solder - and probably also 3D print a case for the GBS. Update: Some sellers have adopted the GBS Control firmware and offer full products based on the GBS 8200 chipsets and the GBS Control mod. The price is a bit more than building one yourself - but still A LOT cheaper than any other (good) scaler solution. On the positive side it also already includes a case and HDMI output. Offers can be found e.g. on Amazon or AliExpress. Search for "GBS Control". No test has been docuemted so far with a CPC, so there's still a risk that the hardware behaves differently from a self-built GBS mod.
===== RGB2HDMI =====
[https://www.youtube.com/watch?v=2CnsQBGAuos The new star on the horizon.] An open source project, that combines a Raspberry Pi with some custom logic, to convert signals from home computers and home consoles to HDMI. For almost every computer there is a more or less different version of the board. You can build the RGB2HDMI yourself or buy a finished version, e.g. on sellmyretro.com . It's features are even beyond those of the OSSC and Framemeister. Its total price is somewhere between the GBS and the OSSC, depending on where you buy it. And its tiny. Its biggest disadvantage is, that you need a different version of the board per console or home computer (well - some computers share a similar signal, so e.g. for the BBC you can also use the CPC version, but e.g. an Amiga or an Amstrad Plus each need another converter version). Screen lag has not been measured yet for it, but it seems to be very low.
===== vga4cpc =====
This DIY project by forum user gregg is based on the Raspberry Pico and (as of November 2024) the only solution that supports most (all?) CRTC tricks. Even games like Relentless that do not render properly on any of the other scan doublers are perfectly playable and absolutely smooth. Hardware and software are publicly available and the scan doubler can be built for less than €30 (€10-€30, depending on shipping costs for the parts). Assembly should be doable for anyone with average soldering skills.
Githup project: https://github.com/grzegorz-gr/vga4cpc
Forum thread: https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/vga-through-rpi-pico-how-many-colors-possible-on-border/
The only downside would be that it only supports the Amstrad CPC, so if you own other computers (or even a Amstrad Plus or GX4000), you still need another solution.
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| [[File:Vga4cpc.jpg|thumbnail]] || [[File:Picovgacase.jpg|thumbnail]]
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''Eto''
== Links ==
CPC Wiki
* [[TV_SCART_cable|How to - Scart cables]]
* [[LCD And Plasma TV Solution]] (Composite Video)
* [[Power Supply for CPC and CPC plus]]
* [https://github.com/ramapcsx2/gbs-control GBS Control for GBS8200]
* [https://www.youtube.com/watch?v=7VOsOuQ5mhM Screen Lag - explanation and comparison video]
* [http://15khz.wikidot.com List of 15kHz compatible monitors]
* https://15khz.net similar list
[[Category:Hardware]] [[Category:Peripherals]] [[Category:DIY]] [[Category:Graphic]]