Mac Emulation / Daydream for NeXT

[Pat the Cat]

I wonder if an 040 powered Amiga could make a good go at emulating a similar flavor of NeXT machine.

Couple problems with that - one is the lack of a DSP. 3120 murders an 040 on FPU calculation. Admitedly the NXT implementation can't do a lot else, but on its own it's a game changer.

Another issue is that there are still quite a few Amiga apps and utils that won't run on an 040, which itself murders the 68882 chip for FPU calculation.

I guess if you could somehow bodge an 882 replacement that was like 50 times faster, it would give you similar level of performance, Amiga to NXT. An extremely difficult hack to implement.

[Pat the Cat]

For balance, programming the Motorola DSP56001 (not to be mixed up with the AT&T 3120) will probably melt your brain unless you take great care, so I'd rather stick with the '040 FPU, given the option

We covered the DSP56001 in more detail than I found comfortable while I was at unversity, in the lecture on computer architecture and parallel data processing.

If I remember correctly, the DSP56001 did not see much use in the "normal" NeXTSTEP operating system and application software context. One notable exception was the Mandelbrot set renderer application which demonstrated how much faster the DSP56001 floating point operations would be than the '040 FPU's capabilities. However, the GCC version which shipped with system only supported the FPU, but not the DSP56001...

First, my mistake, it was 3210. Which wasn't built in to many computers.

Being the first 32 bit FP DSP, it has obviously been outclassed by later releases. It was noted at the time that Macs could not natively support it without using Unix (only Quadras aimed at FMV editing had them built in).

What made them popular for some applications was their robustness - 2,000V was what they were rated at. Also, comparing the datasheets from the time, it was approved for 4 different government/military applications. Other DSPs might be approved for one, rarely 2 applications. Timex DSPS generally die at 10 V or so.

Currently I'm studying Aries DSP architecture - awesome ideas spookily close to the Amiga.

[Pat the Cat]

Once upon a time (1995-1996) the idea for OS4 was shaped around that model of NeXTSTEP:



That didn't happen, and interestingly, the year after, Steve Jobs came back to Apple, and here we are... :hammer:

Indeed. If you study  closely the HP PA-RISC releases from the same period, you will appreciate they are basically Hombre without the Amiga chipset nailed on to them. Who made Lisa? Oh yes, HP... Guess they didn't get paid for the chips, like a lot of other companies that did business for Commodore.

[Pat the Cat]

What do you mean?

I mean that basically HP did Hombre anyway, but without the Amiga or Commodore being involved. Which in hindsight was probably a very sensible thing, from HP's point of view.

CBM wanted a games capable machine, HP wanted high end 3D Workstation and server performance. Commodore wanted 10 million customers, HP were delighted with more than 100,000.