Re: [cc65] Should I do Hidden 64?

From: Joseph Rose <>
Date: 2011-04-17 12:52:48
Gábor Lénárt, I thank you for your interest in Hidden64.  It uses dedicated functions to access hidden RAM.  For example, the hidereadb() function first disables IRQs and the kernal/IO, reads a byte, then reenables IRQs and the kernal/IO.  Using Hidden64 requires editing your code, though.  I e-mailed UZ the beta, but I don't see it on the contrib site.

From: Gábor Lénárt <>
Sent: Sunday, April 17, 2011 5:41 AM
Subject: Re: [cc65] Should I do Hidden 64?

On Sat, Apr 16, 2011 at 03:37:03PM -0700, Joseph Rose wrote:
> I'm sorry for being annoying, but here goes...    Hidden 64 is a library
> for cc65 that provides access to the C64's 12k RAM behind the I/O and
> kernal ROM using a method more direct than cc65's em drivers.  It also can
> use the tape buffer--which is almost never used.  Is this a good
> idea?  Would anybody use it?  It helped with my text adventure.

Though I don't know what Hidden64 does, also I am not so familiar with em
drivers, but I think it can be done easily if calls needed for example
kernal, would map in / out kernal on demand, when calls are need them. About
the I/O is quite interesting: if program does direct memory accesses (like
with PEEK, POKE macros, or equvivalnt things by pointers) it's hard to see
if that memory area should be I/O now, or the ram "behind" it. I can't see
how this can be solved easily, but I think it would be more nice to support
the "whole RAM" memory layout, and somehow mark these accesses for the
compiler (PEEK_IO, POKE_IO ? for example). However it would break
compatibility. So I am really interested how this can be solved. So what I
mean is maybe a new layout scheme for C64 where the whole RAM area can be
accessed directly, I always do this, but for sure, then I don't use cc65
library calls or anything which would require kernal is accessable or so ...

- Gábor
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Received on Sun Apr 17 12:53:03 2011

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