Author Topic: How much memory is being used?  (Read 236 times)

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Offline Lomax

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How much memory is being used?
« on: 02:47, 22 June 18 »

Hi Everyone,


I recently picked up an Amstrad CPC 6128 with a Multiface II. The Amstrad was my first ever computer (back in 1986-87). I am keen to learn more about the machine I grew up with. Can anyone can point me to a good resource that describes the Amstrad CPC 6128 architecture? I guess I want to start with a readers-digest type overview of how the thing works - memory, specialist chips, etc.

A specific question I have currently from playing around with this multiface cartridge (which I never had originally but always wanted) - how can I tell how much memory is being used by a program/game? For example, playing Jet Set Willy on an Amstrad CPC 6128 - how can I tell if it is using 64k or the full 128k? I don't know whether I need to dump 64k or the full 128k when saving.


Any info will be appreciated,


'max

Offline GUNHED

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Re: How much memory is being used?
« Reply #1 on: 03:15, 22 June 18 »
If it runs on a 464 it usually will only use 64 KB.  :)

Offline Longshot

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Re: How much memory is being used?
« Reply #2 on: 10:08, 22 June 18 »
In the first file saved by Multiface, you have a status byte about extra-ram.
If the base file is loaded in &4000, then the status byte is at &4000 + (&400E) + &9A
Bits 0 to 3 respectively indicate, if they are 1, that banks C4 to C7 are used.
Bits 4 to 7 indicate, if they are 1, for these same banks, if the files are compressed
I did not look at how the Multiface initializes this status.
Either it is based on the content of the banks (which can cause problems depending on the initial content of the additional ram), or on the fact that the program has connected the banks (which would be recorded by the multiface) ?
Rhaaaaaa

Offline Longshot

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Re: How much memory is being used?
« Reply #3 on: 10:16, 22 June 18 »
I do not know if it can help you, but here is the anti-multiface source.
Rhaaaaaa

Offline Lomax

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Re: How much memory is being used?
« Reply #4 on: 03:36, 06 July 18 »
<snip> Created new thread for the Multiface II specific questions here.
« Last Edit: 03:40, 06 July 18 by Lomax »