lphillips@lpami.wimsey.bc.ca (Larry Phillips) (01/06/90)
In <90005.150000NETOPRBH@NCSUVM.BITNET>, NETOPRBH@ncsuvm.ncsu.edu (Brandon Hill) writes: >I have a couple of questions regarding some hardware projects >I'm thinking of undertaking. > >2) If I wanted another 8520 type device for my personal use, (i.e. > I want some fast bare hardware to mess with while still allowing > the rest of the system to multitask without interference) > where would be the best place in the memory map to place it? If the device is truly for your own personal use, ie. you have no plans to market it, you are pretty much free to put it in a number of different places, all of which could work just fine, but which could be 'illegal' and could cause numerous problems in the more global sense. Example follows: When the autoconfig software goes out loking for devices, it looks in the $E80000 area, and each board found gets placed in successive areas in the pattern $E90000, $EA0000, $EB0000, and so on. It is quite safe, if you know the configuration of your particular machine, to use, for example, $EF0000. Bear in mind that if you add some future, as yet unspecified device, you may have a conflict. > Configuring the device as a system wide resource isn't necessary, > as only a single dedicated application will be using it. I can't emphasize it too much.. do this ONLY if it is JUST for your machine. > There's probably no supported way to add extra hardware, however > I'm sure some schemes are safer than others. Ahh, but there is. It's called autoconfig, and is a way to add hardware without any conflicts whatsoever, and better, to add it in a way that allows it to be a system-wide resource. -larry -- "Cavett Emptor - Let the talk show host beware!" - Evan Marcus +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+
NETOPRBH@ncsuvm.ncsu.edu (Brandon Hill) (01/06/90)
I have a couple of questions regarding some hardware projects
I'm thinking of undertaking.
1) Would it be possible to run the 68000 at a speed other than 7 mhz?
It seems like it would be easy to get, say, a 14 mhz clock from the
28 mhz master clock (dividing it in half) and a 16 mhz 68000 and
more or less double the processing speed.
There are many implications in doing this...i.e. the E clock might need
to be slowed down, as the 8520 timers should stay at the old
frequency.
I'm just mainly wondering if the rest of system would still communicate
with a faster processor (it must be possible, as the 020 and 030
accelerators run [asynchronously] faster)
2) If I wanted another 8520 type device for my personal use, (i.e.
I want some fast bare hardware to mess with while still allowing
the rest of the system to multitask without interference)
where would be the best place in the memory map to place it?
Configuring the device as a system wide resource isn't necessary,
as only a single dedicated application will be using it.
There's probably no supported way to add extra hardware, however
I'm sure some schemes are safer than others.
BlHdaveh@cbmvax.commodore.com (Dave Haynie) (01/07/90)
in article <90005.150000NETOPRBH@NCSUVM.BITNET>, NETOPRBH@ncsuvm.ncsu.edu (Brandon Hill) says: > 1) Would it be possible to run the 68000 at a speed other than 7 mhz? > It seems like it would be easy to get, say, a 14 mhz clock from the > 28 mhz master clock (dividing it in half) and a 16 mhz 68000 and > more or less double the processing speed. This is possible. The CMI PA (Processor Accelerator) uses a derived 14.3MHz clock to give you a faster 68000; some 32 bit accelerators such as the A2620 do this as well. The best way to generate the fast clock depends on what you want to do. A free running crystal lets you pick the CPU speed, but requires extra care in youre design, since everything must be synchronized to the motherboard clocks when the CPU accesses the motherboard resources. A 14MHz clock divided down from the 28MHz clock will act similarly, since there's no guaranteed relationship between the 28MHz crystal and the Amiga chip clocks (especially when you Genlock!). Building a 14.3MHz clock from the C7M and CDAC clocks on the motherboard is a safe approach, yielding a clock that's reliably synched to the motherboard system. > There are many implications in doing this...i.e. the E clock might need > to be slowed down, as the 8520 timers should stay at the old > frequency. You must drive everything on the motherboard at the 7.16MHz rates. The E clock can't change, AS* and DS* must still fall during S2 of the 7.16MHz 68000 cycle, DTACK* must be sampled only on the falling edge of S4->S5, data must be sampled on the S6->S7 edge. In other words, when the fast CPU is talking to any motherboard resource, it must be indistinguishable from a 7.16 MHz 68000. > I'm just mainly wondering if the rest of system would still communicate > with a faster processor (it must be possible, as the 020 and 030 > accelerators run [asynchronously] faster) Asynchronous processors add wait states and synch up to the 7.16MHz clock to look like a 68000. -- Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Too much of everything is just enough
jea@merlin.cvs.rochester.edu (Joanne Albano) (01/08/90)
Is there a known cause for the incompatibility of the
Microbotics Starboard and Processor Acclerators such as
the CSA and CMI? We have a A1000 with grounded PALS and
a Starboard/Stardrive combo and when we install the CMI
processor with 14Mhz 68000 with 68881 it fails until
we uninstall the Starboard. It reads Kickstart and prompts
for the Workbench disk but then soon puts up the Guru
Screen with error = 3.00200E8A. The CMI works without
the starboard and the starboard works without the CMI.
Any ideas? We have not yet terminated the bus because we
have found no information on how to do this?
Thanks for any help you can give.
Joanne
Joanne Albano, Center for Visual Science (716) 275-3055
Room 256 Meliora Hall, Univ. of Rochester, Rochester NY 14627
UUCP: {rutgers,allegra,decvax}!rochester!ur-cvsvax!jea
INTERNET: jea@snipe.cvs.rochester.edud87-khd@sm.luth.se (Karl-Gunnar Hultland) (01/10/90)
I have been studying the Amiga Technical reference manual and
found something very interresting.
Could I attach a clock faster than 28MHz on the XCLK pin in the video
contact and a switch to XCLK enable and thus get a FASTER amiga.
If this works it would give faster custom chips too, and I'd like
that very much.
Karl
<$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$>
< Karl 'Kalle' Hultland <$> >
< Dept. of Comp. sci. <$> d87-khd@sm.luth.se | >
< University of Lulea <$> {uunet,mcvax}!sunic.se!sm.luth.se!d87-khd >
< Sweden <$> >
<$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$>
< If two people agree on EVERYTHING , one of them is OBSOLETE!! >
<$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$><$>filbo@gorn.santa-cruz.ca.us (Bela Lubkin) (01/11/90)
In article <697@tau.sm.luth.se> Karl-Gunnar Hultland writes: >contact and a switch to XCLK enable and thus get a FASTER amiga. >If this works it would give faster custom chips too, and I'd like >that very much. I've asked about this before (not here) and never gotten a good answer. I'd like to hear from the real hardware gurus on this. Obviously many components of the system will not stand up to being sped significantly; yet, as with most electronics, you could probably get another 20-30% out of it. There is a MAJOR side-effect: you speed up the video timing. This means that your video output will not work on anything but a specialized monitor or a multisync (and then only if it covers the right range of scan rates). This also means that the pixels and lines are closer together -- you might be able to increase the screen size (and keep the scan rates down), but I suspect there are too many hard limits in the video chips to do too much along those lines. It would be very easy to test the idea. Make an external clock box and go for it. I think you can actually get variable-speed crystals if you want to spend a significant amount of money; you could experiment with a large continuous range of speeds. There's enough chance of damaging hardware to say: BE CAREFUL! * Newgroup vote in progress: comp.sys.amiga.hardware; see call for votes in * * news.announce.newgroups. Unambiguous YES/NO votes to trent@ucscb.ucsc.edu * -- Bela Lubkin * * // filbo@gorn.santa-cruz.ca.us CI$: 73047,1112 (slow) @ * * // belal@sco.com ..ucbvax!ucscc!{gorn!filbo,sco!belal} R Pentomino * \X/ Filbo @ Pyrzqxgl +408-476-4633 and XBBS +408-476-4945
daveh@cbmvax.commodore.com (Dave Haynie) (01/12/90)
in article <140.filbo@gorn.santa-cruz.ca.us>, filbo@gorn.santa-cruz.ca.us (Bela Lubkin) says: > X-Claimer: I >am< R Pentomino! > In article <697@tau.sm.luth.se> Karl-Gunnar Hultland writes: >>contact and a switch to XCLK enable and thus get a FASTER amiga. >>If this works it would give faster custom chips too, and I'd like >>that very much. > I've asked about this before (not here) and never gotten a good answer. > I'd like to hear from the real hardware gurus on this. You can go a little bit faster. In order to work nicely with Genlock devices, any Amiga will let you run a clock roughly 5% faster than the basic 28.636MHz (NTSC) clock. Genlocks use the XCLK and /XCLKEN lines and may have some clock slop, but typically not much -- the color clock is very frequency sensitive in video, so if you see color, you are pretty close to dead on, frequency wise. In any case, while there is some slop, this isn't intended to be a general way to boost your system speed. Anything beyond 5% and you're just plain lucky if it works. And of course, if you have some need for color composite video, just about any noticable speedup here will kill your color, though the monitors typically handle the slightly faster dot clock. The other thing to be careful about is the clock quality. The system expects a nice TTL compatible clock applied to XCLK. If you feed it a noisy, analog, or unbalenced (duty-cycle-wise) signal, you have a good chance of creating a flakey system. Some 68020 and 68030 boards may be more sensitive to this clock speed and quality than the main 68000 motherboard, since most use a 14MHz clock of some kind. > There's enough chance of damaging hardware to say: BE CAREFUL! I'd certainly agree with that, as with any hardware hack. Know what you're doing! > Bela Lubkin * * // filbo@gorn.santa-cruz.ca.us CI$: 73047,1112 (slow) > @ * * // belal@sco.com ..ucbvax!ucscc!{gorn!filbo,sco!belal} > R Pentomino * \X/ Filbo @ Pyrzqxgl +408-476-4633 and XBBS +408-476-4945 -- Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Too much of everything is just enough
billsey@agora.UUCP (Bill Seymour) (01/14/90)
In article <140.filbo@gorn.santa-cruz.ca.us: filbo@gorn.santa-cruz.ca.us (Bela Lubkin) writes: :In article <697@tau.sm.luth.se: Karl-Gunnar Hultland writes: ::contact and a switch to XCLK enable and thus get a FASTER amiga. ::If this works it would give faster custom chips too, and I'd like ::that very much. : :I've asked about this before (not here) and never gotten a good answer. :I'd like to hear from the real hardware gurus on this. Obviously many :components of the system will not stand up to being sped significantly; :yet, as with most electronics, you could probably get another 20-30% out :of it. That's right.You get the faster speed. I've got it hooked to my 2000 via a switch attached to a CMI VI-200 (The NES Video prototyping card wasn't available yet then...) Everything I've tried to run works just fine, and the speed increses are exactly what you'd expect. :There is a MAJOR side-effect: you speed up the video timing. This means :that your video output will not work on anything but a specialized :monitor or a multisync (and then only if it covers the right range of :scan rates). This also means that the pixels and lines are closer :together -- you might be able to increase the screen size (and keep the :scan rates down), but I suspect there are too many hard limits in the :video chips to do too much along those lines. This is actually not as much of a problem as you think. After all, a multisync monitor fixes it. OR you could change the pot on your monitor that adjusts the horizontal roll... Where the *major* problems show up is in accessing the 8520s. You will not be able to use the serial port or the floppy drives with any degree of success. I suppose you could rewrite serial.device to take into account the faster clock and trackdisk.device for the floppies though... :It would be very easy to test the idea. Make an external clock box and :go for it. I think you can actually get variable-speed crystals if you :want to spend a significant amount of money; you could experiment with a :large continuous range of speeds. I have no problems hardware wise at 8MHz. Even my Processor Accelerator worked! (That made me 16MHz...) But the floppy and serial troubles were enough to leave the switch in the 7M position. :-) :There's enough chance of damaging hardware to say: BE CAREFUL! : :* Newgroup vote in progress: comp.sys.amiga.hardware; see call for votes in * :* news.announce.newgroups. Unambiguous YES/NO votes to trent@ucscb.ucsc.edu * :-- :Bela Lubkin * * // filbo@gorn.santa-cruz.ca.us CI$: 73047,1112 (slow) : @ * * // belal@sco.com ..ucbvax!ucscc!{gorn!filbo,sco!belal} :R Pentomino * \X/ Filbo @ Pyrzqxgl +408-476-4633 and XBBS +408-476-4945 -- -Bill Seymour ...tektronix!reed!percival!agora!billsey ============================================================================= Bejed, Inc. NES, Inc. Northwest Amiga Group At Home Sometimes (503) 281-8153 (503) 246-9311 (503) 656-7393 BBS (503) 640-0842
pcooper@orchid.waterloo.edu (pcooper) (01/16/90)
In article <90005.150000NETOPRBH@NCSUVM.BITNET> NETOPRBH@ncsuvm.ncsu.edu (Brandon Hill) writes: > >1) Would it be possible to run the 68000 at a speed other than 7 mhz? > It seems like it would be easy to get, say, a 14 mhz clock from the > 28 mhz master clock (dividing it in half) and a 16 mhz 68000 and > more or less double the processing speed. The CMI Accelerator does just this, it runs at 14mhz. I have one and it only provides 10-40% improvement. Your design might do better. What I've always wanted to try is putting a 68010/14Mhz in the CMI to see what kinda performance I can get. The fastest 68010 I have seen is 8Mhz, so I've never tried this, I'm sure there are faster chips around. There might also be a hardware incompatiblity with the CMI board and the 68010. Not sure. It was roomered that CMI is out of dead, I've still seen the Accelerators being sold though... The CMI board also allows a 68881 with is't own clock. Unfortunaly the 68881 acts as a periferal so almost no software suports it. (Or so I have been told, I don't have the 68881 installed ($$)) Later, paul.