using an FPGA to emulate a vintage computer
in [FPGA]
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From: Charles Richmond on 27 Feb 2010 02:08 Peter Flass wrote: > Scott Lurndal wrote: >> "(see below)" <yaldnif.w(a)blueyonder.co.uk> writes: >>> On 24/02/2010 20:37, in article hm6fbd68gp(a)news6.newsguy.com, "Michael >>> Wojcik" <mwojcik(a)newsguy.com> wrote: >>> >>>> (see below) wrote: >>>>> Just the usual red tape: return address, frame pointer of caller; >>>>> and either >>>>> a static pointer or some housekeeping for 'display' registers (if >>>>> used) to >>>>> access non-locals. But bear in mind that in decent languages arrays >>>>> are >>>>> storable values, so a value array parameter gets copied in toto, >>>>> unlike C. >>>> It will be in C if the array is wrapped in a struct. Letting array >>> That is passing a struct, not an array. >>> >>>> parameters decay to pointers was a feature of early C that couldn't be >>>> changed for historical reasons, but when the standardization committee >>>> added support for struct parameters, they made them first-class. >>>> struct (and not the misnamed "typedef") is C's mechanism for creating >>>> new types and ADTs, so if you want a pass-by-value array in C, the >>>> correct thing to do is to put it in a struct. >>> Yes. Preposterous, isn't it? >> >> Q? Why would anyone want to pass an array by value? >> > > Because you can? In C, you can *not*... :-) -- +----------------------------------------+ | Charles and Francis Richmond | | | | plano dot net at aquaporin4 dot com | +----------------------------------------+
From: rich12345 on 28 Feb 2010 13:54 On Feb 5, 10:19 am, Eric Chomko <pne.cho...(a)comcast.net> wrote: > Has anyone created a copy machine of an old system using an FPGA? I havent, but check out: applelogic.org (it's down right now as far as I can tell) http://www.mirrow.com/FPGApple/ http://mirrow.com/FPGApple/revisited.html http://members.iinet.net.au/~msmcdoug/pace/#Status http://www.applefritter.com/blog/12920 http://c64upgra.de/c-one/ looks like the mirrow.com links aren't working either...
From: Alex Freed on 28 Feb 2010 16:50 rich12345 wrote: > > I havent, but check out: > > applelogic.org (it's down right now as far as I can tell) > > http://www.mirrow.com/FPGApple/ > > http://mirrow.com/FPGApple/revisited.html > > looks like the mirrow.com links aren't working either... > It has changed to alexfreed.com So try http://alexfreed.com/FPGApple and http://alexfreed.com/FPGApple/revisited -Alex. --- news://freenews.netfront.net/ - complaints: news(a)netfront.net ---
From: Ahem A Rivet's Shot on 1 Mar 2010 04:18 On Fri, 26 Feb 2010 13:48:48 -0500 Michael Wojcik <mwojcik(a)newsguy.com> wrote: > Ahem A Rivet's Shot wrote: > > > > No, he's saying that C doesn't really implement an array type, > > the var[offset] syntax is just syntactic sugar for *(var + offset) > > which is why things like 3[x] work the same as x[3] in C. > > That's not quite correct. C does implement an array type (or, rather, > an array type qualifier which can be used to implement arrays of any > object type); it's just not first-class. This is saying the same thing as I did in different terms and with greater detail. -- Steve O'Hara-Smith | Directable Mirror Arrays C:>WIN | A better way to focus the sun The computer obeys and wins. | licences available see You lose and Bill collects. | http://www.sohara.org/
From: Eric Chomko on 1 Mar 2010 12:05
On Feb 26, 5:54 pm, Peter Flass <Peter_Fl...(a)Yahoo.com> wrote: > Scott Lurndal wrote: > > "(see below)" <yaldni...(a)blueyonder.co.uk> writes: > >> On 24/02/2010 20:37, in article hm6fbd6...(a)news6.newsguy.com, "Michael > >> Wojcik" <mwoj...(a)newsguy.com> wrote: > > >>> (see below) wrote: > >>>> Just the usual red tape: return address, frame pointer of caller; and either > >>>> a static pointer or some housekeeping for 'display' registers (if used) to > >>>> access non-locals. But bear in mind that in decent languages arrays are > >>>> storable values, so a value array parameter gets copied in toto, unlike C. > >>> It will be in C if the array is wrapped in a struct. Letting array > >> That is passing a struct, not an array. > > >>> parameters decay to pointers was a feature of early C that couldn't be > >>> changed for historical reasons, but when the standardization committee > >>> added support for struct parameters, they made them first-class. > >>> struct (and not the misnamed "typedef") is C's mechanism for creating > >>> new types and ADTs, so if you want a pass-by-value array in C, the > >>> correct thing to do is to put it in a struct. > >> Yes. Preposterous, isn't it? > > > Q? Why would anyone want to pass an array by value? > > Because you can? In Perl there is the 'shift' statement, which allows access to an array by value. |