SE Basic IV 4.2 Cordelia

Software para o relacionado con el core ZX Spectrum / Software for or related to the ZX Spectrum core
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aowen
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Registrado: 07 Oct 2015, 13:32

SE Basic IV 4.2 Cordelia

Mensaje por aowen » 15 Feb 2016, 11:56

Hi all,

Just to let you know I've given up waiting for esxDOS 1.0 to arrive and I've started work on SE Basic 4.2. This will be a departure from the dual ROM solution introduced in 4.0. Until now there have been two copies of the ROM, one with lo-res screen routines and one with hi-res routines that swap over when you change mode. While I was still supporting the standard Spectrum screen, this was the easiest way to do it. However, now that I'm dropping support for the standard screen and using page 7 of the HOME bank exclusively it means that I've got 7K of unused space before the system variables. I tried moving the system variables and addressing them all via IY to increase the amount of RAM available for BASIC, but it would have required a new version of esxDOS. So instead I'm using the 7K as an extension of the firmware. The standard screen mode will be a 420x192 screen with 40 column text and 8x1 attributes. This will be hard coded into the ROM part of the firmware. However, the hi-res code (for MODE 1) will be copied to the 7K RAM area from the ROM on boot. The upshot of this is that you can load replacement code for mode 1 in software without having to reflash your firmware. So it will be possible for third parties to support other screen modes in software. I am probably going to end up putting the tables in RAM as well which means the Brits will be able to change the COLOR command to COLOUR and non-English speakers will be able to translate the error messages. Once of the really cool things about the extra space is that it provides room for a full 2K font. 8-bit fonts are on all the time now. And of course as these live in RAM it's possible to load in any code page you like. There should be lots of ways to customize SE Basic to tailor it to the user's preferences without needing to recompile. I'll post again when I've got a beta version ready.

Cheers!
-Andrew

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Hark0
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Re: SE Basic IV 4.2 Cordelia

Mensaje por Hark0 » 16 Feb 2016, 09:29

Thanks for the info... ;)


... and waiting for beta. :P
http://www.zxuno.com
ZX-Uno · Clon de ordenador ZX Spectrum basado en FPGA.

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Radastan
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Re: SE Basic IV 4.2 Cordelia

Mensaje por Radastan » 16 Feb 2016, 09:54

¿SE BASIC Will support Radastan video mode? It would be GREAT.

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aowen
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Re: SE Basic IV 4.2 Cordelia

Mensaje por aowen » 08 Mar 2016, 01:50

Radastan escribió:¿SE BASIC Will support Radastan video mode? It would be GREAT.
Well it won't have built-in support for it, but it should be possible to support it in software by replacing the hi-res code that lives in the RAM part of the firmware. [Edit] With the caveat that it will only support it with the video in bank 7, because bank 5 is used for the firmware in SE Basic 4.2.

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