[zxspectrum] [SEMIOT][SPAM] - Interfaccia video color per ZX81
- From: Eugenio Ciceri <zx.eugenio@xxxxxxxxx>
- To: zxspectrum@xxxxxxxxxxxxx
- Date: Wed, 22 Oct 2014 00:59:51 +0200
Ovviamente era "ZX81"... ma a quest'ora il sonno sta vincendo ;-)
2014-10-22 0:58 GMT+02:00 Eugenio Ciceri <zx.eugenio@xxxxxxxxx>:
> Qualcuno la conosce già?
>
>
> ------------------------------------------------------------------------------------------------------
> Hello
>
> I’m pleased to announce the launch of the Chroma 81 interface, a new
> multi-purpose interface for the ZX81. Its primary function is to allow the
> ZX81 to be connected to a TV via a SCART socket using an RGB connection to
> produce a picture that is sharp and bright. The Chroma interface plugs into
> the expansion port of the ZX81 and connects to the TV using a standard
> SCART cable. There is no need to make any modifications to the ZX81 since
> the Chroma interface only requires access to those signals available on the
> expansion bus.
>
> An exciting feature of the Chroma interface is its ability to add colour
> to the ZX81's display, with support for a palette of 15 colours and 2
> colour modes. One mode provides an attributes file similar in concept to
> that of the Spectrum, giving maximum flexibility in creating a colour
> display but can only be used by new software developed to explicitly
> control it. The other mode allows colours to be assigned for each character
> in the character set, and then whenever a character is displayed it will be
> shown in its defined colours. The colour mappings are retained across a
> LOAD and so it is possible to load a game and for it to be displayed using
> the defined colours, i.e. existing games can be colourised!
>
> But the features of the Chroma interface don’t end there, as it also
> provides the following:
> - An onboard 16K RAM pack.
> - Additional 16K RAM that be mapped into the 48K-64K region, or the 8K-16K
> region.
> - Support for a user definable character set within the RAM located in the
> 8K-16K region.
> - Support for WRX graphics format, allowing true high resolution graphics.
> - QS Character Board emulation, allowing a user definable character set
> and operating with the range of Quicksilva games that supported the
> original character board.
> - A ROM cartridge socket that allows complete overriding of the ZX81 ROM,
> making it possible to run replacement operating systems or ROM
> enhancements, e.g. the Skywave FORTH ROM, the ComprocsysASZMIC ROM, the
> dk'tronics and Kayde Graphics ROMs. The socket is compatible with my range
> of ZXC ROM cartridges, including the recently released ZXC4 that contains a
> 4MB FLASH ROM (opening the potential to store 100s of games on a single
> cartridge for instant loading).
> - A Cursor joystick socket, with support for auto-fire joysticks.
> - An RS232 socket, which could be useful for connecting to a printer,
> modem or a PC (a ROM cartridge program is already available to allow
> loading and saving via RS232 from a PC).
> - Output of LOAD/SAVE sounds through the TV speaker(s).
> - A set of configuration switches to allow each facility to be enabled /
> disabled, ensuring maximum compatibility with all existing hardware, e.g.
> ZXpand.
> - A full width, gold plated rear expansion bus.
> - A reset button.
>
> The Chroma interface is constructed from a professionally made board that
> measures only 10cm by 10cm. You can see a photo of the interface and read
> further details about the facilities it offers at:
> www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface.htm
>
> There are a few points worth being aware of before ordering:
> - The interface only outputs a picture in RGB format (not composite video
> or S-video).
> - The interface has only been tested with 50Hz models of the ZX81, i.e. UK
> and Europe. In theory it will work with NTSC versions but this has not been
> proven.
> - The interface has not been tested with any clones of the ZX81 and must
> therefore be assumed to be incompatible with them.
> - It is strongly recommended to use the 1.2A version of the ZX81 power
> supply. The original 0.7A version might not be sufficient if other devices
> or a ROM cartridge are to be used. If more current is drawn than the power
> supply can safely handle then it could overheat and pose a fire risk.
> - The SCART output accurately reflects the picture available from the RF
> output. Slight shimmering or bending of the top row of the picture will be
> visible if it occurs in the original RF output.
> - Flat screen TVs made by Panasonic do not appear to implement the SCART
> specification correctly and can result in the Chroma picture being shifted
> to the left or at worst being unstable and continually jumping
> horizontally. There may be other TV models that also do not display the
> picture from the Chroma interface correctly, but most makes appear to work
> ok.
> - The interface is fully compatible with the ZXpand SD card interface.
> - Flicker-free games originally developed for use with the ZX80 fitted
> with the 8K ROM upgrade may not display a perfectly stable picture due to
> inaccurate timings in the games. A TV tends to be far less tolerant of
> frame timing variations in a SCART signal than it is in an RF signal.
> - A SCART cable is not included. Almost all commercially available RGB
> SCART cable will be suitable, allowing you to select your preferred length.
> - A RS232 cable is not included. If your PC does not have a built-in
> serial port then a USB-RS232 adapter can be used. A standard 9-way
> non-crossover serial cable is suitable for use with the RS232 socket, and
> can be used to connect to a serial printer or a PC (although note that
> custom software must be created to control the RS232 port).
> - The ROM cartridge socket supports my ZXC4 ROM cartridge, which contains
> a 4MB FLASH ROM. The ZX Cartridge Creator utility (for Windows) can be used
> to program a single ZX81 ROM file only into a ZXC4 ROM cartridge using a
> Spectrum. It will soon also support the ZXC3 ROM cartridge. In the future,
> I will be enhancing the Cartridge Creator software to allow multi-program
> compilations (.ROM and .P files) to be constructed and downloaded to ZX81
> using RS232, and then the ZX81 will program the data directly into the ZXC3
> or ZXC4 ROM cartridge.
> - The Chroma interface is uncased (I hope to be able to offer a custom
> case in the future if economically viable).
> - The main logic IC and onboard 5V converter do get hot in use but this is
> expected behaviour.
> - Modern TVs tend to struggle to display the RF output from a ZX81.
> However, it is usually possible to obtain enough of a picture to prove that
> the ZX81 is operational. You should only connect the Chroma interface to a
> ZX81 that you are confident is in working order else damage may occur to
> the Chroma interface.
>
> The cost of the interface is as follows:
> - Chroma interface = 60.00 GBP
> - Postage and packaging (Signed For / Tracked delivery):
> - Within UK = 4.75 GBP
> - Within Europe = 9.75 GBP
> - Outside Europe = 11.15 GBP
>
> The easiest payment method is PayPal and my account is
> rainbow@xxxxxxxxxxxxxxxxxx
>
> I am able to provide ZXC4 ROM cartridges, which can be used with either
> the ZX81 or the Spectrum. Please email me if you would like price details.
> Full details of the ZXC4 can be found on my website.
>
> Regards
>
> Paul Farrow
> www.fruitcake.plus.com
> www.zxresourcecentre.co.uk
>
>
> ------------------------------------------------------------------------------------------------------
>
> E qui c'è anche un'interfaccia per lo Speccy che permette risoluzioni
> colore più alte:
>
>
> http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm
>
>
>
>
>
>
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