Author Topic: demo-upper-rom for the cpc6128  (Read 674 times)

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Offline cpcuser

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demo-upper-rom for the cpc6128
« on: 10:58, 29 October 16 »

How to create pliece a demo-upper-rom for
the cpc6128 and start it?




thank you.
greeting

Offline Ast

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Re: demo-upper-rom for the cpc6128
« Reply #1 on: 11:58, 29 October 16 »

Hi,


If you wanna do an upper rom demo, your demo will start at #c000 and finish at #ffff....
It's impossible to do a 100% Rom demo, so you will use, the ram too.
Why ? Because you can't change any data on Rom. Rom is only "Read Only Memory", so all counters and all automodifications code will be do into Ram. That's the only way.


Using rom quick access :


Code: [Select]
di
ld bc,#7F80+%0110 ; connect upper rom+select mode 2
out (c),c
ld bc,#df00+rom number  ; (0-#1f) if rom max is 31
out (c),c                             ; then select the rom you want to use....
....                                      ; here you re connected into the rom selected!




I hope my words could help you in your demoway ! bye...
« Last Edit: 12:00, 29 October 16 by Ast »
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Offline arnoldemu

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Re: demo-upper-rom for the cpc6128
« Reply #2 on: 14:31, 29 October 16 »
How to create pliece a demo-upper-rom for
the cpc6128 and start it?




thank you.
greeting
Example here:

http://www.cpctech.org.uk/docs/manual/s158se09.pdf

page 9.3.

Use "EMS_ENTRY" to poke basic and move it I think.
OR, set HL,DE and set lower memory address to do the same.

This example is more complex, but shows how to reserve space for rom (in upper ram, but you can also reserve space in lower ram):

http://www.cpctech.org.uk/source/filesys.asm

My games. My Games
My website with coding examples: Unofficial Amstrad WWW Resource

Offline cpcuser

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Re: demo-upper-rom for the cpc6128
« Reply #3 on: 19:57, 01 November 16 »
hello,wery  good.


thanks.


greeting