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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Gulliver on August 21, 2007, 12:05:39 AM
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I have an A600 and a spare 68030 micro, so i though i could figure if it is feasable building an accelerator card for it.
Please do correct my assumptions and clarify my doubts if possible!
Q: How do i stop the 68000 from working?
A: Using the HLT pin i can let the other micro get control
Q: How do i synchronize the accelerator micro at eg 25mhz with the 7 mhz A600 bus? Can i overclock safely the A600 bus?
A: ???
Q: 68000 is 16 bit externally, 68030 is 32 bits. How do i join data signals?
A: I guess i shoul join the 16 bit 68000 data to the LSB of the 68030. Dont know!
Anyway its a hobby project, and to keep it small and simple, and cheap, i wont put ram or a rtc on it.
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I wonder if wait states need to be included.
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I thought abou waitstates but i found several designs claimed to have Zero wait states! How? I dont know!
So, ATM the only solution regarding bus synchronization would be to acces the A600 bus according to its 7mhz clock rate thus providing a great performance penalty not to use the accelerators speed.
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Not including any fast RAM is also going to be a big performance
penalty. Either way, this is a massive project.
Something I thought about a few years ago was desoldering the
A600's 68000, adding a socket, and dropping in a pin-compatible 68010.
Negligible speed improvement, but it would have a VBR which is helpful
for WHDLoad.
I'm hoping Jens Schoenfeld brings his A600 accelerator into production
soon.
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I am also waitin for Schoenfeld accelerator, but anyway i would like to know how to build one.
Of course an accelerator without mem is a huge penalty! But i wanted to do one thing at a time, first learn how to properly accelerate an Amiga and then add all other beauties such as Fastram, RTC, Local bus expansion etc.
It is easier doing it little by little, than attempting to do it in one shot.
Yep 68010 is better than 68000, but 68030 is far better!
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For ideas of what needs done, read up on teh Frances project.
ftp.funet.fi /pub/amiga/hardware/accelerators
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Thanks for pointing me that out billt!
Any suggestions, ideas, criticism?
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From an electrical engineering point of view, it should be relatively easy to adapt Frances to run with a 68030 instead of a 68020.
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Hi
Q: How do i stop the 68000 from working?
A: Using the HLT pin i can let the other micro get control
Nope, A: request the bus (BR) wait till its granted (BG)
and send a BGACK, the 68000 doesnt do anything and you have the bus.
The Haynie archive has the equations for the fastslot found on the A3/4000 which is:
CBR = ’b’1;
BOSS = BG30 # BOSS & !poweron_reset;
BG = local_card_bg;
BG.oe = BOSS;
BOSS is a private BGAck, CBR is just BR.
Q: How do i synchronize the accelerator micro at eg 25mhz with the 7 mhz A600 bus? Can i overclock safely the A600 bus? A: ???
The bus remains unchanced, the main difference is you have to clock the interupts and control signals in. If you have memory or other stuff on board you have to have bus buffers between the card and the Amiga which are turned off whenthe board is talking to something on the same board.
Q: 68000 is 16 bit externally, 68030 is 32 bits. How do i join data signals? A: I guess i shoul join the 16 bit 68000 data to the LSB of the 68030. Dont know!
Have a look at the A2630 user manual or service manual, both have the schematics for the card, an A500/A600 card would be the same! (The PAL code for the card is available on the Haynie archive)
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Gulliver wrote:
I thought abou waitstates but i found several designs claimed to have Zero wait states! How? I dont know!
They're talking about read/write access cycles to fast mem not needing wait states.
Any read/writes to chip mem or motherboard chip registers will still be controlled by the custom chips, so you're stuck with their timing as to when the cycles are terminated.
You might wanna think about making the CPU clock a multiple of the A600 bus to make syncing easier.
IIRC,you're not gonna be able to make use of the 030's cache burst , cos it needs a 32bit data bus to be able to do it.
BTW if haven't already got it, get the MC68030 User Manual (http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MC68030&fpsp=1&tab=Documentation_Tab) from Freescale and read chapter 7 (Bus operation). The bit about Dynamic Bus Sizing answers your earlier question about hooking up the 030 to a 16 bit data bus.
There's also a section on howto use a 030 in a 020 design (such as the Frances board others have suggested)
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Thank you guys, I will defiately take your recomendations, those were the kind of answers i was hoping to get.
Big thanks! :-)
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On the net there is also the PAK68k which was a DIY 030 (?) accelerator for the Atari which went into production (and also worked with the Amiga).
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Any suggestions, ideas, criticism?
I don't know much about Frances, never had one. From memory, which could be rusty since I hadn't seen anything about Frances for at least a decade now, thre was a separate memory card module for it, and they did something weird with a couple address bits that prevented some things from working normally, maybe Mac emulation had problems with it. But it's a start for what you're interested in, and I'd recommend googling for more info about it. There may be some stuff for it on aminet as well, but I just grabbed the first link that came up for you. I think I came across a bare PCB for it in a pile of stuff I got somewhere, the CPU module only I think, but don't know where it might be now. It was the long skinny 68000 style though, not the squar one I think the a600 has.
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On the subject of the Schoenfeld A600 accelerator. My question is why bother? Why not do an A500 accelerator instead? First, you have the numbers. There must be tens of thousands more A500's in the world than A600's. Second, you have more room inside the case and you dont have to build something that is going to pop off the top of the chip everytime the system is moved.
I would think a nice 020/030 accelerator with simm module socket and simple IDE controller would sell pretty well I would think. A500's are cheap to buy.
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Olecranon wrote:
On the subject of the Schoenfeld A600 accelerator. My question is why bother? Why not do an A500 accelerator instead?
The size of the A600 is it's best feature. It is small, easily tidied away, wife "acceptable".
Couple that with it's built-in IDE interface (for WHDLoad), PCMCIA interface (for networking) and video modulator for direct hookup to the TV makes the A600 better than an A500 hands down.
you dont have to build something that is going to pop off the top of the chip everytime the system is moved.
The Schoenfeld A600 accelerator screws in place, no "popping off" when moved.
I would think a nice 020/030 accelerator with simm module socket and simple IDE controller would sell pretty well I would think.
If you made one, you'd never make your money back.
A500's are cheap to buy.
A600's are cheap to buy.
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billt wrote:
For ideas of what needs done, read up on teh Frances project.
ftp.funet.fi /pub/amiga/hardware/accelerators
Lucas (Little Ugly Cheap Accelerator System) was the Accelerator. Frances (Fast Ram At Nominal Cost for Expanded Storage) was the ram expansion for it.
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Will use an A600 because i have one! I dont have an A500, but then its the same bloody micro with a different layout, so in theory it would be dead easy to use one or the other.
On the other hand it is a hobby project, not a commercial venture. The reason is simple, i love electronics and Amigas, so i was in the hope i could learn something by building the accelerator. Of course i would like to add an IDE interface FASTRAM, a local bus expansion for other add-ons, but then trying to accomplish so much from the start will probably end up in a pipe dream, and will make me fail in achieving my main goal: building an accelerator.
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A600's are cheap to buy.
Maybe in the UK. Here in the US they are pretty rare and tend to run 2x-5x the cost of an A500. Of course if Jens doesn't really care about selling accelerators in the US, you got me on the argument.
The size of the A600 is it's best feature. It is small, easily tidied away, wife "acceptable".
Couple that with it's built-in IDE interface (for WHDLoad), PCMCIA interface (for networking) and video modulator for direct hookup to the TV makes the A600 better than an A500 hands down.
Shrug.. Toss a simple IDE interface and a clockport on the accelerator and your good to go. The idea of connecting a computer via composite to a TV makes my eyes bleed just thinking about it. Besides, it seems like they put SCART connectors on everything in Europe. You probably have SCART connectors on your toaster ovens over there :lol: My point is, I dont consider composite video output a big winning argument for the A600 over A500 debate. When your about to plunk down 100's of dollars for a CPU upgrade, you probably have the cash to connect your A600/A500 to a display with a better method than composite.
If you made one, you'd never make your money back.
So your saying an A600 accelerator would be profitable but an A500 (with it's vastly superior unit count) accelerator would not be profitable? The only way I can see that is if the A600 version was significantly cheaper.
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I remember Lucas/Frances.
Back in 1993/1994, when it appeared, I was green and a N00b, I sent some $$'s to order the boards...., Guess what, They *NEVER* arrived.
Anyone know of a program that can actually read the data files that are in the archives ?
I know they are just text files, but will Pcad2006 read these older files ?
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Gulliver wrote:
Of course i would like to add an IDE interface FASTRAM, a local bus expansion for other add-ons, but then trying to accomplish so much from the start will probably end up in a pipe dream, and will make me fail in achieving my main goal: building an accelerator.
You are aware that adding fastram to an Amiga is part of what is involved with accelerating them?
The CPU being able to access dedicated memory speeds things up. Hence accelerating the Amiga.
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Hi Gulliver and everyone,
One this page is some details of a fairly recent DIYish 68030 accelerator design for the a1000 / Phoenix Board by a German guy I think it was off a1k.org. Maybe there is some info for you?
http://www.gb97816.homepage.t-online.de/projekte.htm
I wouldn't mind building the deinterlacer myself.
Good Luck!
John
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@Unit01
Thanks, I will look into it!
I am just sorting some things out, and polishing my knowledge on the design.
I will get back on you with my findings!
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remove the 68000 from the mobo and replace it with the much better 68030 ;)
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Olecranon wrote:
Alexh wrote:
If you made one, you'd never make your money back.
So your saying an A600 accelerator would be profitable but an A500 (with it's vastly superior unit count) accelerator would not be profitable?
Nope. What I am saying is that neither would make their money back ;-)
Jens did an A600 accelerator, because he wanted to do an A600 accelerator. It interested him, he probably liked the quirkyness of the smallest Amiga and was inspired by Christian Krenner http://www.amiga600.de
Jens did not do it because it was going to make any money because (when you factor in his time) there is no way he would a profit.
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I'd hope for something else than SIMM RAM, actually. Mostly because SIMMS are getting hard and expencive to get hold of. Ideally a m68k acc-card would ship with RAM soldered on board, maxed out... 128MB for 030, isnt it?
I keep dreaming of "modern" amiga acc-cards (A500,A600, A1200, CD32), with buildt in RAM, ethernet and USB - ready to be fitted with our old 030+882, 040 and 060 chips. :-)
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kolla wrote:
SIMMS are getting hard and expencive to get hold of
Have you tried? You can get them all over the place for almost nothing.
I keep dreaming of "modern" amiga acc-cards
Keep dreaming.
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@alexh
Have you tried? You can get them all over the place for almost nothing.
Really?
Do you have en example website?
I am looking for simm modules
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Lucas (Little Ugly Cheap Accelerator System) was the Accelerator. Frances (Fast Ram At Nominal Cost for Expanded Storage) was the ram expansion for it.
Oops, sorry. I knew thre wqas a seperate memory board but couldn't remember much abotu it all, must have got them backwards. Thanks for the correction. Hopefully it at least led the OP down a useful road.
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whiteb wrote:
I remember Lucas/Frances.
Back in 1993/1994, when it appeared, I was green and a N00b, I sent some $$'s to order the boards...., Guess what, They *NEVER* arrived.
LUCAS came out in 1986.
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pyrre wrote:
@alexh
Have you tried? You can get them all over the place for almost nothing.
Really?
Do you have en example website?
I am looking for simm modules
I have a BOX full of 4 & 8 Mb SIMMs in here. If you want to pay the postage from Brazil, simply PM me saying the quantity (I DO NOT SELL THEM, I'LL GIVE IT 2 U!).
I'm pretty sure you guys on europe & USA don't have those flea markets around... :roll:
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pyrre wrote:
Really?
Do you have en example website?
I am looking for simm modules
http://www.scan.co.uk 64Mbyte single sided = £8.99
http://www.microdirect.co.uk 32Mbyte single sided 72-pin SIMM = £5.29
These were the first two I looked at. I am sure you can find more elsewhere.
Availability of 128Mbyte FPM 72-pin SIMMS has gone down and so price has gone up amazingly. Roughly 10x the price of a 64Mbyte EDO SIMM.
128Mbyte EDO SIMMS are also going up, about 3x the price of a 64Mbyte one.
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Hey alexh: since we're talking about SIMMS, any ideas on where to find a single-sided, or very thin double-sided 128 MB SIMM that would fit a Phase 5 1260 accel., or a DCE 1230 SCSI module? Be very grateful if you have any ideas....
128MB isn't much when you do 3D rendering......
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AFAIK they never made single sided, or low profile 128Mbyte SIMMS.
I remember using an elastic band to hold bigger ones in place.
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Hey alexh: since we're talking about SIMMS, any ideas on where to find a single-sided, or very thin double-sided 128 MB SIMM that would fit a Phase 5 1260 accel., or a DCE 1230 SCSI module? Be very grateful if you have any ideas....
I bought a very slim 128mb 72 pin simm, see the a.org topic on 50ns simms here (http://www.amiga.org/forums/showthread.php?t=30523)
On the second page is a few links to pics of the Simm I have.
I got it from AEmemory (http://www.aememory.co.uk/EDO-FPM-memory.html) for £14
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Nice. Very slim, a bit taller than normal but nothing too bad.
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oli hd: many, many thanks for the link.
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alexh wrote:
kolla wrote:
SIMMS are getting hard and expencive to get hold of
Have you tried? You can get them all over the place for almost nothing.
Well, have to add cost of package, postage and .. sigh.. customs. It's not like I can just buy one in the stores.
A friend of mine tipped me about http://www.memoryx.com which appear to do it themselves, and hence they do not run out of stock :-)
I keep dreaming of "modern" amiga acc-cards
Keep dreaming.
Will do :-D
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alexh wrote:
Nope. What I am saying is that neither would make their money back ;-)
Jens did an A600 accelerator, because he wanted to do an A600 accelerator. It interested him, he probably liked the quirkyness of the smallest Amiga and was inspired by Christian Krenner http://www.amiga600.de
Jens did not do it because it was going to make any money because (when you factor in his time) there is no way he would a profit.
Is that really why its been listed as "on hold"? I'd have thought he'd have no trouble selling it and if he has done the dev work surely why not recoup that cost by selling some?
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Methanoid wrote:
I'd have thought he'd have no trouble selling it and if he has done the dev work surely why not recoup that cost by selling some?
1) He would have to finance the production. ( say a minimum production run of 200 units each €100 thats €20,000!!)
2) He would have to devote time, source the parts, arrange the manufacture, work out the testing, sort shipping etc.
He's very busy with non Amiga related work and the free time and money he told me is to be devoted to Clone-A development.
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I thought a little more about my A600, my accelerator, and made my own mind about some things:
I hate SMC designs, they are not for hobbysts
I dislike ICs which are not DIL for the same reason
So what the hell was i doing with an A600 in the first place! I will try to find an A500 and continue work with it. It is so much easy to hack! Anyway as i mentioned before it is just a different micro layout, and Schoenfeld is about to sell his own, so i dont want to infringe any damage as little as it coul be, to his company!
I made up my mind: an A500 on-chip accelerator, will fit with no troubles many Amiga models as some of you have stated previously (A2000, A1000, A1500, etc).
I read about the Lucas accelerator and the Frances memory board. Too much interesting mental notes were taken in that process, and i eventually could draw some conclusions about my own project.
Even though, i need some help here!
68000 to 68030 interface:
As stated in the Lucas accelerator project, the idea is to make the 68030 resemble an 68000 at 7mhz to the amiga system bus. However, both microprocessor are not pin to pin compatible and have a few different control signals not to mention speed. So this is the actual challenge!
Differences to be solved:
1- Different clock rates
2- Data and Address signals
3- Bus length,/DTACK vs. /DSACK0 and /DSACK1
4- Byte addressability, /UDS and LDS vs. /DS
5- E clock generation at 1/10th of clock signal (0.7mhz)
The help i need is regarding item number 4. In the Lucas accelerator some PAL equations are mentioned, which i dont understand. However, these signal conversions were done in a PAL, i wish someone could point me in the right direction, so i can make them with 74xxx logic ICs.
I have allready covered all the other items mentioned, i wish you could tell me if there is something else i am missing here!
:rtfm:
Thanks
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Just a little hi-jacking on this thread but a bit related. When I read this thread, some ideas came up. I wonder whether they're anywhere near feasible: (you experts can probably tell :-).
a 4MB fast ram expansion like the old ones which used the cpu socket and then the cpu on top of if. I was thinking of design like the A600 accelerators, with the cpu beneath it.
an "accelerator" with just an 68010 (like Matt_H said; for WHDLoad) and 4MB fastram. A design like this would not change the buswidth because of the almost similar processor. You'd "only" need to stop the onboard 68K processor and take all the signals.
Should I keep on dreaming, or is there any point?
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Hi there,
i think that the problem is that only one cpu has to connected to the amiga circuit.
If that is the case,but you need the original 68k of the a600 so as to flip on the plcc socket,then
why dont you cut the +5v line from the original cpu so as to go inactive,while obtaining external +5v to the accel board.
it could be a solution.
cut the power from the onbaord 68k ,it goes in active then add power to the second cpu on the accel board.
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I wonder if it is possible to clock officially 16 MHz 68hc000 to 32 MHz?
When I was thinking I was buying some DIP-64 HC000:s, I got some very rare shrinkdip-64 MC68HC000B16 chips in the mail. Ebay-link (http://cgi.ebay.com/Motorola-68000-Processor-MC6800HC000B16-16MHz-2_W0QQitemZ230165084107QQihZ013QQcategoryZ4663QQssPageNameZWDVWQQrdZ1QQcmdZViewItem)
Now I don't know what to do with them :-? :crazy:
I have more than a dozen of them, should I build accelerators from them or what?
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if i remember correctly there is a 28mhz signal on the amiga mobo for denise? ive heard of 8mhz clocked over 20mhz but not to 28. a 16mhz might do.
still youd have problems of locking the machine amigas have a very tight cpu/chipset/os messing to much can cause problems. more ram and a slight speed up would be better.
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If you did you could start with something like this design (http://eab.abime.net/showpost.php?p=363645&postcount=49).
Andy
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AmiJIm wrote:
cut the power from the onbaord 68k ,it goes in active then add power to the second cpu on the accel board.
it doesn't work that way. there was a proper way of halting the onboard CPU with the bus signals but I don't remember right now. Anyway check 68000 bus specifics for more information.
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Actually, you need to "ask" the original processor to grant the bus takeover.
This is made by a short "negotiation" between the two chips. The second CPU sends a "BR" (bus request), then the 1st give a "BG" (bus granted). After that, the 2nd CPU sends a BGACK (Bus Granted Acknowledgement) and takes over and the 1st becomes halted (that's why the CPU on the motherboard of the Amiga becomes hot, even if it is not used).
This works in any Amiga accelerator exactly this way.