Groups > comp.sys.apple2.programmer > #210

Re: Best place to hide about 30 bytes in //e RAM

Date	2012-03-03 14:10 -0500
From	Steven Hirsch <snhirsch@gmail.com>
Newsgroups	comp.sys.apple2.programmer
Subject	Re: Best place to hide about 30 bytes in //e RAM
References	<jite2e$7vc$1@news.xmission.com>
Message-ID	<VJSdnWiZfuoI8c_SnZ2dnUVZ_vWdnZ2d@giganews.com> (permalink)

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On 03/03/2012 10:41 AM, Egan Ford wrote:
> Programmers,
>
> I just created a program launcher that I'd like re-activate on CTRL-RESET. I
> know that I have no control over the programs being launched and that there
> will be a chance that my reset vector bytes ($3F2-$3F4) may get hosed, but in
> the event they do not, where is the least likely place someone will use
> memory? I tried page $BF with the worse results. Right now I am starting at
> $310 with good results, but I'd like better results if possible.

How about the beginning of the stack page?  IIRC, few (if any) programs get 
that close to the end.  I hacked up a modified version of the RamFast ROM that 
copied a small software loop into that location to speed things up when 
running with ZipChip or TransWarp 2e accelerators (where DMA is a 
non-starter).  Never saw a problem with stack collisions.

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Thread

Best place to hide about 30 bytes in //e RAM Egan Ford <datajerk@gmail.com> - 2012-03-03 07:41 -0800
  Re: Best place to hide about 30 bytes in //e RAM Steven Hirsch <snhirsch@gmail.com> - 2012-03-03 14:10 -0500
    Re: Best place to hide about 30 bytes in //e RAM Hugh Hood <hughhood@earthlink.net> - 2012-03-04 17:55 -0600
      Re: Best place to hide about 30 bytes in //e RAM Hugh Hood <hughhood@earthlink.net> - 2012-03-04 17:57 -0600
        Re: Best place to hide about 30 bytes in //e RAM Egan Ford <datajerk@gmail.com> - 2012-03-05 08:55 -0700
  Re: Best place to hide about 30 bytes in //e RAM Antoine Vignau <antoine.vignau@laposte.net> - 2012-03-03 12:53 -0800
  Re: Best place to hide about 30 bytes in //e RAM "ict@ccess" <gids.rs@sasktel.net> - 2012-03-03 18:47 -0800
  Re: Best place to hide about 30 bytes in //e RAM Egan Ford <datajerk@gmail.com> - 2012-03-04 11:33 -0700
    Re: Best place to hide about 30 bytes in //e RAM "ict@ccess" <gids.rs@sasktel.net> - 2012-03-04 19:19 -0800
      Re: Best place to hide about 30 bytes in //e RAM Egan Ford <datajerk@gmail.com> - 2012-03-05 08:56 -0700
        Re: Best place to hide about 30 bytes in //e RAM Antoine Vignau <antoine.vignau@laposte.net> - 2012-03-05 14:25 -0800

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