EXTERNAL SCREEN

[xavisan]

No problem, we'll continue in English, pachic I was refering about MPAGD.

[pachic]

Johathan, Hello, We need peek and poke in the MPAGD
Regards

[pachic]

Xavi, Ramon, We have 1 screen works with 3 areas of 2048 bytes, and then think if we save the screen but We use by areas, example load area 1 in area 1 or load area 2 in area 1. We can reuse for different phases in the game, example 1 area for the final scene, other for intro and other for game over
We make routines especific for that , whe I use USER 2, just put in area 1 all area 1, USER 3, put Area2 in Area 2.....

Regards

[xavisan]

That's how sprites or backgrounds were loaded in Spectrum before, you drew everything on a screen and loaded the area you wanted, to view it later, is that it pachic ?

/Xavi

[ramon]

OK. let's do it I will prepare an infrastructure with the following elements: A loader program to load the data into the memory banks, a compression method so that the tape load does not take forever, a memory dump routine with source and destination parameters to load the What we want. I think we already have all of that. It will be easy.

[pachic]

perfect, the idea is load by parts, and you can use part of screen in each scene (intro, game over and game completed), the colour is the problem

[ramon]

The spectrum’s screen memory starts in memory immediately after the spectrum rom, at address #4000 (16384d). Our 256x192 pixels are stored 8 pixels to the byte in 6,144 byes of memory (32 bytes by 192 rows). The colour attributes were stored immediately after the pixel data from address #5800 (22,628) in 768 bytes (32 x 24 character of data).

www.overtakenbyevents.com/lets-talk-about-the-zx-specrum-screen-layout/

We can easily divide into 3 zones just like the splash screen is processed. In a more complex way if you want more divisions, six for example.

[ramon]

the screen dump routine was this:

showSplash

; Volcado de pantalla
di ; esperad todos un momento!
ld b,6 ; quiero ver este banco de memoria
call bankScreen ; cambia a ese banco
ld hl,$c000 ; desde origen
ld de,$4000 ; hasta pantalla
ld bc,6912 ; todos estos bites
ldir ; cópialos
call bank0 ; mira ahora al banco 0 (el de siempre)
ei ; ya podeis seguir con vuestras cosas
ret ; gracias


The parameters to manipulate will be these:


ld hl,$c000 ; desde origen
ld de,$4000 ; hasta pantalla
ld bc,6912 ; todos estos bites
The new routine something like this:


showSplash2

; screen dump
; Parámeters:
; hl = origen
; de = screen address
; bc = longitud
di ; everyone wait a minute!
ld b,6 ; I want to see this memory bank
call bankScreen ; switch to that bank
; load records hl, bc, de
ldir ; copy data
call bank0 ; now look at bank 0 (the usual one)
ei ; you can continue with your things
ret ; thank you



[ramon]

TESTING A PROTOTIPE:

A table of adress can be deduced by this article:

wiki.speccy.org/cursos/ensamblador/gfx1_vram

the tested prototipe:

server routine:


showSplashparam
; screen dump
; Parámeters:
; hl = origen
; de = screen address
; bc = longitud
push bc
di ; everyone wait a minute!
ld b,6 ; I want to see this memory bank
call bankScreen ; switch to that bank
pop bc
ldir ; copy data
call bank0 ; now look at bank 0 (the usual one)
ei ; you can continue with your things
ret ; thank you

Client routine

showSplash1
ld hl,$c000 ; pixel from origen
ld de,$4800 ; to screen
ld bc,2048 ; all this bites
call showSplashparam
ld hl,$d800 ; atributos from origen
ld de,$5900 ; to screen
ld bc,256 ; all this bites
call showSplashparam
ret
Video adress Table : VIDEO DATA.xlsx (12.21 KB)

Require MPAGD Sound Mod.

final coming soon.

[ramon]

Version parche pachic.rar (14.39 KB)

try and have fun.

To install: unzip the file into the SuiteZX directory just like you did with the xavisan patch. Previously MPAGD Sound Mod is required.

[xavisan]

Feb 21, 2023 8:00:05 GMT ramon said:

OK. let's do it I will prepare an infrastructure with the following elements: A loader program to load the data into the memory banks, a compression method so that the tape load does not take forever, a memory dump routine with source and destination parameters to load the What we want. I think we already have all of that. It will be easy.

Woooooww!!! 

[xavisan]

Feb 25, 2023 10:51:50 GMT ramon said:

Version View Attachment

try and have fun.

To install: unzip the file into the SuiteZX directory just like you did with the xavisan patch. Previously MPAGD Sound Mod is required.

I have to try it ;-) as soon as I have a while I'll get to it, let's see how it goes. you are amazing ramon

[pachic]

Grande Ramón, esto va a permitir usar pedazos de pantallas para distintas partes y ahorrar
Abrazo