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Re: CPC text mode

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On Wednesday, 11 January 2017 19:01:13 UTC+11, Matthew Phillips  wrote:
> In message on 11 Jan 2017 CP/M User wrote:
> 
> > On Saturday, 2 July 2016 04:09:47 UTC+10, Matthew Phillips  wrote:
> > > In message on 1 Jul 2016 B. P. TBC wrote:
> > > 
> > > > Has the Amstrad CPC 464 a real text mode, like the C64? Or the CPC has 
> > > > only graphics mode?
> > > 
> > > The CPC 464 only has three graphics modes.  All modes are 200 pixels high
> > > (25 text lines of 8 pixels).  MODE 0 is 160 pixels wide, MODE 1 is 320
> > > pixels wide and MODE 2 is 640 pixels, with 4, 2 and 1 bits per pixel
> > > respectively, so all 16K.
> > 
> > The Amstrad has an 4 Graphics Mode if you include the more obscure 4
> > coloured Mode 0, it works differently from MODE 0 in that a hidden screen
> > can be drawn and displayed based on the INKs. From what I can tell it has't
> > been widely used and as MODE 0 offers up to 16 colours, it's more effective
> > to use that MODE when writing games.
> 
> It's not known to the MODE command, is it?  Nor is it mentioned in the
> documentation of SCR SET MODE.

It is a mode in it's own right, though I'm unsure if the firmware recognises it, There was an article about it along with a BASIC RSX driver program. I posted some examples on the CPC-Wiki a while ago:

http://www.cpcwiki.eu/forum/programming/double-buffering-and-frame-flyback/msg91485/#msg91485

using that program along with an example of my own, but found it wasn't really viable for using in games and for any games programmers who made any wire-framed graphical games (e.g. Tank busters), it would of been easier to just use MODE 0 and Flip to the visible INKs for drawing the graphics once they have been drawn.

> It's possible to do various tricks with the Amstrad hardware, like split mode
> screens, and extra tall screens, but careful use of interrupts and switching
> the screen memory location, so it may well be possible to produce a 160 pixel
> wide screen with only four colours.  But I've never seen anything written
> about it in any of the Amstrad computer magazines in my collection.

Perhaps analyse the RSX program from "The Fourth Mode" article to see, what I found of that program was it was a bit on the slow side while switching from the hidden screen, that to me suggests Firmware is involved, but wouldn't be as straightforward as a "SCR SET MODE (&BC0E)" as the 2 screens are within the 16kb block.
 

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Thread

CPC text mode "B. P. TBC" <tbc_z87@mailbox.hu> - 2016-07-01 15:04 +0200
  Re: CPC text mode Matthew Phillips <spam2011m@yahoo.co.uk> - 2016-07-01 19:09 +0100
    Re: CPC text mode "CP/M User" <cpm22_user@yahoo.com> - 2017-01-10 22:30 -0800
      Re: CPC text mode Matthew Phillips <spam2011m@yahoo.co.uk> - 2017-01-11 08:00 +0000
        Re: CPC text mode "CP/M User" <cpm22_user@yahoo.com> - 2017-01-13 13:48 -0800
          Re: CPC text mode Matthew Phillips <spam2011m@yahoo.co.uk> - 2017-01-14 16:10 +0000
            Re: CPC text mode "CP/M User" <cpm22_user@yahoo.com> - 2017-01-14 18:01 -0800

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