Amiga DSP - Doing Something Productive
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- เผยแพร่เมื่อ 23 ก.ค. 2024
- A Digital Signal Processor chip was included in the design of the prototype Amiga 3000+ and AA3000 computers. This would have boosted the maths performance significantly compared to the A3000.
I coded up a Mandelbrot render program for the DSP chip on the replica AA3000+ motherboard to put it through its paces compared to a 68060 and find out what might have been if Commodore had put its prototypes into production.
Once I've ironed out all the bugs, I'll release the binary and source code for this program. - เกม
Hello,
Well done for having managed to revive the DSP planned for the Amiga.
What, in my opinion, could be interesting would be to see a comparison of the performance of the DSP against the onboard 68030 and 68882, as well as against a 68040 (A3640). To me, it's a good way to realize what we missed at the time.
In addition to the mandelbrot, a JPEG display comparison would be really interesting.
I also hope one day to be able to hear the DSP audio 16 bit 8 channels and MP3 playback.
Congratulations again to everyone who made this video possible.
Thanks for the comments. I agree with your "wish list" comparisons. The bit that is holding this back right now is that the DSP is very temperamental with the CPUs/accelerators it will work with. Some not at all (eg A3640 and onboard '030 - which is totally weird) and some only partly (eg CSMk2). Atm, I don't know why that is, and until someone with a logic analyser takes a look at it, we're not likely to make much progress.
@@wrangleramiga896 I didn't know for the onboard 68030 or A3640. All we can do is to hope that one of you can get them to work, as you did for the DSP. We waited 30 years to already see this video, we can wait a little the rest (well not 30 more years anyway :))
@@wrangleramiga896 If it's not working with the onboard CPU, then I think that the version of the 3000+ that these replicas are based on might not be the newest version that commodore did. Either that, or they never got the DSP up and running themselves.
@@kyle8952 May be and May be Hese can fix that with a future motherboard revision
The delphina DSP boards seemed to work quite will (different DSP) and to answer a previous question were quite happy to play mp3 properly. The 50Mhz 060 could not really play mp3 at all well with 100% CPU use.
Having by default a dsp which was probably way cheaper then a 060 giving this kind of speed bump would be quite a thing
Yes, completely agree! Shame Commodore missed the opportunity.
And of course it was available a few years before the '060. Just having the DSP with the original '030 would also have eliminated all the compatability and optimisation issues with lots of existing software that the '060 would have suffered from even if Commodore hadn't gone bust, you've just got a decent ('030) with good compatability and with which developers are familiar and a distinct quasi FPU in the DSP chip. You'd probably have to wait until 1995 or 96 to be getting the best out of your '060 and of course that wouldn't solve problems with older software.
To try and eliminate some of the chip-ram access overhead you could try changing the approach a little. Doing horisontal lines instead of vertical lines and then only writing to the chipram every 32 pixel - i.e. taking 32 individual calculated pixels from the dsp-interupts and keeping them in an internal cpu-register (or even fast-ram) and then only moving a single longword to chipram in one go - seems like that would remove the most excessive overhead.
Subbed! =D
Hi all.... great video 😁
Thanks!
Hi. which software support DSP chip ?
Sadly, not much. Search for mandel_dsp on Aminet and you will get the Mandelbrot generator I'm showing in this video. Also on Aminet are asm3210 and gcc3210 which are the programming tools I created to write other software for the DSP. I'm waiting for someone to write a jpeg or mp3 decoder!
Interesting. How does it compare to the DSP in the Atari Falcon?
I'm not familiar with the Falcon but from what I read it's DSP was a Motorola DSP56001 at 33MHz whereas the AA3000+ has an AT&T DSP3210 at 50MHz. So different clock speeds and architectures eg the 560001 has 2x56-bit floating point accumulators whereas the 3210 has 4x40-bit FP accumulators. Very difficult to compare without running a head to head somehow!
Falcon's DSP56001 has 96kB 0-waitstates internal RAM, Amiga's AT&T 3210 8kB internal RAM. Other DSP parameters: Falcon: 32MHz, Amiga: 50MHz; Falcon: 56bit math, Amiga: 32bit math; there are also more differences.
@@wrangleramiga896
From Freescale'sy DSP56001/D document
"The data paths are 24 bits wide thereby providing 144 dB of dynamic range; intermediate results held in the 56-bit accumulators can range over 336 dB."
@@blast4722 Falcon's DSP math is fixed point 24 bits. DSP32 supports fixed point INT32, DSP-FP32, IEEE FP32 and FP40.
@@wrangleramiga896 560001 is fixed-point arithmetic.
DSP56000 uses fixed-point arithmetic, with 24-bit program words and 24-bit data words.
Are you the designer of this motherboard? I did see this board on an Amiga forum but it looked as though ordering the board was no longer possible.
Also does Dave Haynie have one of your recreations?
I was tempted to see if it would be possible to order a few as this was a machine I always wanted.
No, I don't have the skill to make anything like that! The designer is Hese and the sales channel is a thread on Amibay. I don't think these boards or the DSP software have made their way to Dave Haynie. Hopefully he would be pleased to see his prototype produced in numbers and running software!
@@wrangleramiga896
I was thinking of possibly buying one but was tempted to possibly buy one for Dave Haynie too (I would love to see his comments on this design for something which never found the light of day). The Amiga forum I came across (I think it may have been Amibench) seemed to look like no future orders so I think I would need to pay higher than usual. Also whilst I could solder it together I am not sure I would feel comfortable at all doing it.
I have a very rare prototype (one of two; though I own the lesser of the two). I was tempted to lend this to either Hese or Chucky to reverse engineer and make the design available. When Dave auctioned lots of prototypes; it was the only one which I could win over his then boss (Ryan).
Looks like Hese is taking orders still on the Amibay thread and he has an assembly service too. I'd be interested in some pics of your prototype!
@@wrangleramiga896 It is the lesser of the two Gemini prototypes. There are pictures of it on The Big book of Amiga hardware.
I bought the lesser one before Dave found the other one :(
Still - a very nice piece of hardware!
Is the DSP capable of mp3 decoding?
I can't say for sure, but I would expect so. We'll only know when someone tries it!
@@wrangleramiga896 A3000+ DSP 3210 has only 8kB internal RAM. It could be not enough for mp3 algorithm.
@@blast4722 maybe there's a pin compatible DSP with a bigger feature set?
@@jkdsteve good question and actually I have no idea. Maybe would be easier to create a drop-in replacement with FPGA and e.g. with more RAM