- Original Message -
From: Si Owen <[EMAIL PROTECTED]>
To:
Sent: 22. dubna 1999 16:41
Subject: RE: Win32 SimCoupe (was: Z80 flags for INI(R) and OTI(R)? #2
(oops!))
> Aley Keprt wrote:
> > I can't imagine the situation, where unions are inefficient.
> > Go a
Aley Keprt wrote:
> I can't imagine the situation, where unions are inefficient.
> Go and try it and you will see.
> The Z80 emulator I use in my programs use unions and it looks very
> efficient.
I've done it already and it didn't actually seem to make much difference to
the performance from my t
Aley Keprt wrote:
> I can't imagine what algos can be better than reading a one single value
> from a table. Especially in this case, when every table has 256 bytes, and
> there are some 4 or 8 tables in the Z80 emualtor. Is this too much for
> Celeron's cache? I don't think so.
Probably not from
> Don't forget -- the cache comes into play here a lot, so tables aren't
> necessarily as efficient as you might think. PROFILE YOUR RESULTS!!!
>
> Simon (NSFMSFT)
I can't imagine what algos can be better than reading a one single value
from a table. Especially in this case, when every table has 2
> On Tue, 13 Apr 1999, Si Owen wrote:
>
> > It'd probably work if done as a C union, but I wasn't sure how efficient
> > that'd compile up to be compared to the simple variable version. I might
> > give it a try with HL to see what different it makes.
> >
> > Si
>
> I was under the (probably ill-in
On Tue, 13 Apr 1999, Si Owen wrote:
> It'd probably work if done as a C union, but I wasn't sure how efficient
> that'd compile up to be compared to the simple variable version. I might
> give it a try with HL to see what different it makes.
>
> Si
I was under the (probably ill-informed) impre
Ian Collier wrote:
> It was basically a choice between keeping 8-bit quantities and
> shifting+ORing whenever register pairs are used, and keeping 16-bit
> quantities and shifting whenever single registers are used. I made the
> choice arbitrarily as it seemed easier to deal with the 8-bit registe
On Wed, Apr 07, 1999 at 04:10:53PM +0100, Si Owen wrote:
> Ian Collier wrote:
> > Does the Amstrad DSK format not cover this? (I don't actually
> > know anything about it, except that it is more complicated than
> > a straight dump of all the tracks on the disk.)
> I've not found any official doc
Simon Cooke wrote:
> Don't forget -- the cache comes into play here a lot, so tables aren't
> necessarily as efficient as you might think. PROFILE YOUR RESULTS!!!
I completely agree - my Celeron only has 128K of cache but it's running at
full clock speed (464MHz for my setup) giving it a nice boos
From: Si Owen <[EMAIL PROTECTED]>
> Aley Keprt wrote:
> > Well, I have used another Z80 CPU emulator in my SAA1099 player.
> > It is not 100%, but it uses very efficient algo's for computing flags.
> > And it is platform independent. This may help.
>
> Sounds good - I'd come across the look-up tabl
Aley Keprt wrote:
> Well, I have used another Z80 CPU emulator in my SAA1099 player.
> It is not 100%, but it uses very efficient algo's for computing flags.
> And it is platform independent. This may help.
Sounds good - I'd come across the look-up tables in another Z80 emulator and
wondered about
> > Z flag but left the other part of the expression alone. It's a great C Z80
> > emulator, and I can't see there being much else to squeeze out of it without
> > going to ASM
>
> Actually I think I just typed in what came into my head - I'm sure some of
> the flag calculations must be horribly
Simon Cooke wrote:
> Nothing time-critical would be in Java - I mean, yeuck! - but I don't mind
> having the overhead of C++ for a disk controller :)
Would it need to be time critical? Wouldn't it be running in 'emulator'
time anyway, so it'd only need to stay in sync with that?
> Si (NSFMSFT)
Ian Collier wrote:
> Does the Amstrad DSK format not cover this? (I don't actually
> know anything about it, except that it is more complicated than
> a straight dump of all the tracks on the disk.)
I've not found any official docs for it but I've flicked through the
comments in some ASM code tha
On Tue, Apr 06, 1999 at 04:15:16PM +0100, Si Owen wrote:
> In the floppy driver I've added the direction flag and write protection, and
> tighened up some of the flags used. I'm playing with the idea of yet another
> disk format capable of handling custom disk formats used by some of the
> commerci
From: Si Owen <[EMAIL PROTECTED]>
> In the floppy driver I've added the direction flag and write protection,
and
> tighened up some of the flags used. I'm playing with the idea of yet
another
> disk format capable of handling custom disk formats used by some of the
> commercial software (and possib
Hi Allan,
> Before I go on, I would just like to say thanks to Si for taking on
> SimCoupe for Win32.
Hope you don't mind if I pick your brains from time to time :-) I'm working
to get most of the original functionality up and running under Win32 before
letting anyone at it. Even then it'll stil
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