| re .0
I personally have not heard anything on the turbo board for
the ST, I get ataris usenet postings everyday, so I keep my eyes
open for it.
as for replacing the 68000 in the st with a 68020, that won't work
hardware wise, or software wise. the pinout on the 68020 is different
from that of the 68000. Software wise, you are right, there are
instructions that work in super only on 68010/68020 cpu's, but work
on 68000. One that comes to mind, is the status register, which
is similar to the process status longword on a vax. You can look
at it on a 68000 when in user mode, so a user program would be able
to tell if he was in supervisor or user mode, this is dissallowed
(read fixed) on the 68010/68020. The 68010 is pin for pin compatible
with the 68000, but replacing the 68000 with it will not work for
software reason 2. The 68010 and 68020 supply more information
on the stack when an "access violation" occurs, this is one of the
trap vectors ( i think busserr) this was done so that these later
cpu's could support virtual memory, the 68000 did not put enough
information on the stack to restart the offending instruction, but
this is not possible on the 68000.
Yes, from what I hear the operating system on the amiga supports
the 68000/68010/68020, they wrote the operating system that way.
Mayby one of the amiga owners who peruse this file could verify
this.
Bill Powers
|
| AmigaDOS automatically detects the presence of any Moto chip. I've
used a 68010 for over a year with virtually no problems. A few
games from England bomb on the 68010. There is a PD patch, just
a few hundred bytes long, called Decigel, that traps any illegal
instructions. So far, it's worked great. The speedup averages
about 5-8% according to my precison benchmarks :^) but can be as
high as 50%. For some strange reason, Deluxe Music re-maps it's
instruments at warp speed with the '010 installed.
There are quite a few ways to add a 68020 to an Amiga; three companies,
(Four, counting CBM) are shipping 68020/68881 boards.
The correct way to add an '020 is to add 32 bit RAM. If you just
add a 14.4 MHz '020, the performance increase is underwhelming,
since the '020 has to throttle down to fetch stuff from 16 bit memory.
The Amiga OS uses 32 bit relative addressing. If 32 bit memory
is present, the program will go there. There are a few exceptions,
such as MicroSoft AmigaBASIC, which uses 24 bit addressing (probably
a Mac port).
I posted a similar question in the Mac notes. I was curious as
to how most Mac software, written with 24 bit addressing, would
run on a Mac II, which is a true 32 bit machine. Apparently, Apple
invented a FMMU chip (Fake Memory Managment Unit) which magically
corrects things.
One of the nicer things about Amiga OS 1.3 will be the capability
to automaticaly detect the presence of a 68881 math chip, and use
it totally transparent to the application. Any calls to the software
math library will be shuffled off to the math chip.
By the way, I've played around with a Mac II a bit, and it really
doens't seem much faster than our department's SE. Didn't do any
math with it, and it does have a bit more screen to manage, but
it just didn't FEEL much faster.
The SE now feels about as fast as STs that I've played with.
Ed.
|
| Like I said, the 68010 is hardly noticable. In fact, I bet if you
removed it, I'd never know the difference.
I think a much more interesting Atari project would be to interface
a 68881 math chip somehow. I don't know enough about the ST to
see how this could be done. Does TOS/GEM use software math libraries
that are callable from an application? If so, maybe a new library
could be created that diverts to the math chip. Do any C or Fortran
compilers offer 68881 support?
|
| <<< BOLT::MAY14$DUA1:[NOTES$LIBRARY]OLD_ATARIST.NOTE;1 >>>
-< atari ST notes >-
================================================================================
Note 773.0 16Mhz Turbo Board Coming for the ST... 4 replies
ASPEN2::BOIKO 13 lines 7-MAR-1988 21:50
--------------------------------------------------------------------------------
I just talked to the people at Megabyte Computers in Texas,
about their new 68000 16mhz turbo board for the 520 and 1040 ST
line. The price will be right around $200, and so far all the software
they have tested with the prototype has run without a problem. The
upgrade will come in either kit form or you will be able to send
your ST to them. Atari is working with them on this project as well
as, a bus adapter off the cartridge port (blitter chip can be attached
off this bus/board)- this second project will not be finished till
summer.
Their phone number is (713) 338-2231.
-mike-
================================================================================
Note 773.1 16Mhz Turbo Board Coming for the ST... 1 of 4
ASPEN2::BOIKO 6 lines 7-MAR-1988 21:53
-< and..One More Thing... >-
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re .0
There will also be a switch, which you can use to switch between
8Mhz and 16Mhz cpu clock speed...
-mike-
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Note 773.2 16Mhz Turbo Board Coming for the ST... 2 of 4
UTROP1::TRAMONTINA 15 lines 8-MAR-1988 09:19
-< What about Cache? >-
--------------------------------------------------------------------------------
-< new 68000 16mhz turbo board >-
re .0
The 16 Mhz board sounds very actractive to me. But I have a
few questions about it.
1. How great is the performance increase? (2 times as fast???)
2. Does the board use Cache memory to overcome the difference in
speed between memory (8 Mhz) and proccesor (16 Mhz)? Or does the
proccesor use wait-states?
Renato
================================================================================
Note 773.3 16Mhz Turbo Board Coming for the ST... 3 of 4
RDGENG::KEANE 54 lines 8-MAR-1988 16:05
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re .2
A very good question!!
I have a mini car that I can drive down the freeway at 80 mph, if
I buy another, Am I able to drive down the freeway at 160 mph??
The real question is what are you going to do with the extra time
this board is going to save you ?, sit waiting for your disk drive
to catch up?. For CPU intensive programs it will obviously speed
things up, perhaps it may make Gem programs' interrupts on the
mouse fast enough to be usable, but for my general mix of use, ie
first wps and document processing, second graphics, third games, my
priority is still to get a faster, larger disk system.
AS stated in .2, the rams must start to limit the throughput,
is there a wait state in current machines ??.
Still IT is GOOD that somebody somewhere still believes enough in
the Atari to develop some new products for it. I get the feeling
from the USenet that there is a lot of disenchantment with Atari
at the moment, in the US.
In UK the machine is selling like hot cakes, mainly at the games
market upgrade. In Germany and Holland there appears to be a really
well supported machine base with a lot of TEckky products, ROm boxes,
bus convertors, gofast co-processors etc.
Ps. Did you see the flameogram from the guy on the usenet who had
just found out there were a batch of STFM's sold whose internal
drive did not recognise write protected disks ? This was confirmed
from a second subscriber.
To see if you have a bad disk drive.
1) write protect two floppy disks that have files on them.
2) put the first in your machine, take a directory.
3) change to the second diskette.
4) Press escape to take directory of second disk.
5) If directory of first disk is refreshed without a disk access
then YOUR drive doesnt recognise write protect ( The O/S uses the
write protect as a media change flag apparently)
6) Complain to Atari and they may change your drive for you.
TTFN
Pat K.
================================================================================
Note 773.4 16Mhz Turbo Board Coming for the ST... 4 of 4
CIM16::POWERS "I Dream Of Wires - GN" 22 lines 8-MAR-1988 20:43
-< Enquiring Minds Want to Know >-
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Does anyone know hardware wise what they are doing to speed
the machine up. For example simply putting in a faster cpu and
clocking it at a faster speed will not work. What about the
chips that atari developed, does anyone know if they are capable
of being operated at twice the speed. Also, the way these systems
operate, is they often take the cpu clock speed, and divide it for
clocking other things (chips). For example, right now on the st
atari takes the 8mz clock speed divides it by 16 and sends this to
the 8250 ACIA this gives the proper baud rate for the midi port
of 31250 baud. I am sure this happens for all the other major
components of the st such as the serial port, the disks, etc.
Is this a whole new redesigned motherboard, where we have to pull
out our chips on our st's, and put them in the new board?? Another
thought, do they use another cpu chip other then the 68000. The
last I knew, the highest you could clock a 68000 was 12.5 mhz.
Does anybody know if motorola has introduced a faster version?
Bill Powers
|