Ok, i haven't read all the posts on this, but why not stick the code in
LMPR and use IM1 - saves having the table of vectors.
Adrian
** UIP Sam Port 4100+ lines of z80 and climbing
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of David Brant
Sent: 21 May
I have to admit I was wondering the same. IM2 was necessary on the speccy
because 0x38 was in ROM and couldn't be paged out but I see no reason not
to use IM1 on the Sam. I'm quite happy to be told otherwise, of course :)
Geoff
On Wed, 21 May 2008 13:50:14 +0100, Adrian Brown
[EMAIL PROTECTED]
Adrian Brown wrote:
Ok, i haven't read all the posts on this, but why not stick the code in
LMPR and use IM1 - saves having the table of vectors.
That's my favoured approach too.
** UIP Sam Port 4100+ lines of z80 and climbing
Woo! It's so tantilisingly close!
David Brant wrote:
But then
Has to be said the first thing my code does is page itself into LMPR addr 0 and
sit there :)
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Geoff Winkless
Sent: 21 May 2008 14:46
To: Adrian
Subject: RE: Short, short questions
I have to admit I was
Hi,
I'm using IM2 in ... um, a current project ... in which I have more spite
drawing code than will fit in 32k. Thus I need to keep the screen in one half
of memory while the other half is a moveable window into other pages.
If I used IM1 this would require that either, a) the screen goes in
If you interrupt routine is small, could you not also just switch off
the first one or two scanlines of your display, and even grab a few
extra cycles out as a result? Or can you not enable and disable the
display per scanline?
And, yes, I know I'm missing the point with this question, I'm just
Really it was related to my first question - I was considering the
plausability of moving my data table to be positioned around address
zero when I wrote the post. And obviously a table that reaches 2kb in
either direction from address 0 covers address 0x0038.
Tests last night with an older,
Andrew Collier wrote:
If I used IM1 this would require that either, a) the screen goes in
sections A
and B, and the interrupt routine is actuially visible in pixels - or b)
the
moveable window goes in sections A and B, and I have to duplicate the
interrupt routine in nearly every page of
On Wed, 21 May 2008 15:29:28 +0100, Colin Piggot [EMAIL PROTECTED]
wrote:
Andrew Collier wrote:
If I used IM1 this would require that either, a) the screen goes in
sections A
and B, and the interrupt routine is actuially visible in pixels - or b)
the
moveable window goes in sections A and B,
On Wed, May 21, 2008 at 03:16:07PM +0100, Thomas Harte wrote:
If you interrupt routine is small, could you not also just switch off
the first one or two scanlines of your display, and even grab a few
extra cycles out as a result? Or can you not enable and disable the
display per scanline?
Hi,
Literally anything? On many of the machines I have written emulators
for, most things are usually completely changeable but some things are
loaded internally — especially on any machine that has a variable
screen start address.
Also, one further question: am I right to think that the Sam has no
Thomas Harte wrote:
Literally anything? On many of the machines I have written emulators
for, most things are usually completely changeable but some things are
loaded internally — especially on any machine that has a variable
screen start address.
Not literally anything, you can change the
Hi,
Well - at least, any of the things you can ever change, yes! screen on/off,
border colour, palette, screen mode, ram page, etc.
Early versions of SimCoupe didn't support these changes better than once per
line. I remember Allan (or was it Simon?) telling me he had never realised
that the
On Wed, 21 May 2008 17:09:32 +0100, Andrew Collier
[EMAIL PROTECTED] wrote:
Correct. Always non-interlaced (despite various examples on Fred of
flickery pictures which purported otherwise).
While (on a TV with 576 visible lines) you won't be able to get a 192 line
output device to output
But Sim Coupe duplicates all known characteristics of the real
hardware now, right?
I was actually involved in writing emualtors as early as 1998, and
most of the early ones were horrible. Pretty much anything by Marat
Fayzulin or derived from his source still is — they're usually run
the CPU for
On Wed, May 21, 2008 at 05:28:58PM +0100, Thomas Harte wrote:
But Sim Coupe duplicates all known characteristics of the real
hardware now, right?
All the ones that I know about, certainly. Even the little ASIC quirks like
single-pixel vertical lines in the border (this is something Simon Cooke
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