Re: [Ql-Users] Memory contention (CPU / ULA)

2007-08-14 Thread Palenicek Jan
Thanks Marcel!

I'm no hardware guy, but I'm pretty sure the ULA locks ALL internal
memory during screen refresh, i.e. depending on model (EU/US) 50 or 60
times per second. The CPU cannot access anything at all during these
times.

OK, I will measure read/write time in the vram anyway. ULA should somehow share 
bus with CPU, it should not lock memory the whole TV frame refresh.

Some memory expansions like the Trump Card are not as limited, you
do not get any delays accessing the extended RAM there.

On Amiga there is Chip RAM and Fast RAM. Chip RAM is shared between CPU and all 
coprocessors. In chip RAM is program running slower, because coprocessors has 
priority over CPU. Fast RAM is used only for CPU, therefore program runs faster 
here.

I think this is case of Trump (and Sandy?). Extended memory is Fast and base 
lower 128k of RAM (??? or 64k of VRAMs only?) is Chip (slow), because it's 
shared with ULA. The same exists on ZX Spectrum, but it's well 
documented/implemented feature of ZX hardware. I think Sinclair didn't reinvent 
the wheel and used the same principle on QL.

 Is there any emulator emulating that feature?
No emulator comes anywhere near a cycle-exact emulation.

OK. Thanks.
--

www.icq.atlas.cz/
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Re: [Ql-Users] SBASIC extras

2007-08-14 Thread George Gwilt

On 11 Aug 2007, at 13:57, Dilwyn Jones wrote:


 PAR_WAIT  (presumably something to do with parallel port)


This is part of SMSQ/E but its definition is not in my QPC2 manual.  
The code seems to set a pause for a period of time. Perhaps the  
author knows what  for?

George
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Re: [Ql-Users] SBASIC extras

2007-08-14 Thread Marcel Kilgus
George Gwilt wrote:
 PAR_WAIT  (presumably something to do with parallel port)

 This is part of SMSQ/E but its definition is not in my QPC2 manual.  
 The code seems to set a pause for a period of time. Perhaps the  
 author knows what  for?

That would be Tony.

According to the QDOS Classic docs:

-=-=-=
PAR_WAIT (port, wait cycles) sets the length of time that the parallel
port drive will wait for the printer to be ready before it gives up
and lets the Q40 do something else. This has no effect in FIFO mode,
but in original PC mode it allows the buffer in the printer to be
stuffed in bursts. The default value is 0. The larger the value, the
higher the probability that a more than one byte of data can be sent
on each interrupt, but the higher the load on the machine.

If the IO card does not provide IRQ7 and the machine is busy,
PAR_PULSE with have a much greater effect than if IRQ7 is used and/or
the machine is idle.

PAR_WAIT 2,20give the printer on PAR2 a high priority.
PAR_WAIT 0   . . . set PAR 1 use the minimum of processor time.

For an Epson Stylus COLOR Pro printer, PAR_PAUSE 10 and PAR_PAUSE 50
improved the transfer speed by 30% on an idle machine: the rate was
primarily determined by the printer. On a busy machine with no
interrupts, PAR_PAUSE 10 improved the transfer speed by a factor of 3
and PAR_PAUSE 50 improved the transfer speed by a factor of 5. The
speed of other tasks in the machine was reduced. Q40 Hard Disks
-=-=-=

As far as I can see it does not have any effect in the latest SMSQ/E
versions at all.

Marcel

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Re: [Ql-Users] QDOS4Amiga

2007-08-14 Thread Stephen Usher
Ian L. Pine wrote:
 Mauny Amiga 1200s had an internal hard disk, yours doesn't seem to. Oh
 well, this means that you'll be swapping floppies a great deal and I'm
 not sure that QDOS4Amiga will actually fit on one and be usable.
 
 Hmmm. Might be more trouble that it's worth then.  I haven't looked inside
 the case because the machine isn't mine, but if the connectors for the hard
 disk are provided inside, what type of disk would work - I have a spare 6Gb
 ATA one?

2.5 laptop IDE drives.

Steve

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