Why C= never made a 65816 based machine?

[WolfToTheMoon]

And not talking specifically about Amigas, but as a C64/C128 successor. Seems like an obvious plan, full backwards compatibility with their 8 bit machines, plenty fast and cheap, up to 16 MB RAM, they were granted half of the licensing cost by WDC... Yet it never happend! And I think it would make for a very powerful entry level machine in the late 80s and early 90s... certainly more impressive than C65, which to me made little sense by 91'. A GUI based OS like GEOS could have been used/licensed by C=...

Perhaps it would be dangerously close to lower spec Amigas, but I think it made sense to try and build on the foundations of 20ish millions of C64 sold and the huge software library that existed.

[WolfToTheMoon]

There was such a machine; it was called the 128.

It was still 8 bit and pretty limited. .. I was thinking more of a next generation entry machine...a 16 bit CPU, expandable RAM, 3.5" floppy, GUI based OS...

[WolfToTheMoon]

Sounds like an a500

yes it does, but it would be cheaper and have backwards compatibility with C64 software. Plus, a 20 MHz 65816 is faster than a 7 MHz 68000 so it could a very interesting package. Timeframe around the original C65, 90-91', A500 would be replaced with A1200 in a year, A600 would not be needed.

[WolfToTheMoon]

I'm not sure "faster" == "faster" in this case...

desiv

Well, Wozniak did say Apple demanded that the 65816 in the II GS was clocked at only 2.8 MHz to make sure it didn't threaten the Mac performance and sales. In his own words, a 7 MHz 65816 is about as fast as a 14 MHz 68000 - but I'll stipulate that a 68000 is the more advanced and more elegant solution better suited to higher level languages.

[WolfToTheMoon]

It wouldn't have had meaningful backwards compatibility, just like the C65.
In 1989 they should have had an 020 machine with chunky graphics.
 

I'm not sure that the 20mhz 65816 used by CMD was available that early either.

Around 90', max from WDC was 12MHz... Doesn't really matter, even a 7 MHz 65816 will be more than fast enough.
Compatibility can be improved thru emulation.

[WolfToTheMoon]

Although, here he listed purely technical reasons:
http://www.1000bit.it/support/articoli/apple/a2gs/interview_woz.asp



And it's hard to imagine that the 65815 is twice as fast as the 68000, although I suppose that all depends on what you're doing with it...
With the Mac, it was doing everything, so that 7Mhz 68k did feel really slow....

desiv

65816 is much more cycle efficient than 68K... as long as your using 16 bit data and relatively simple instruction, it can be even more than 2 times the speed of an 68000... however, 68000 is much faster on 32 bit ops and has more registers and more instructions... it's a better chip, no doubt, but a well optimized code for the 65816 will FLY!!!

[WolfToTheMoon]

You wouldn't be able to do it, if you emulated the 6502 your timing would be all wrong & you don't have enough processing power to emulate enough in software to relax the timing issues.
 
By 1990 the amiga was underpowered, spending money on developing another underpowered computer doesn't make sense.

There's no need to emulate 6502, there's a compatibility mode in 65816.

You're missing the point... yes, it wouldn't be the fastest machine around, but that's not what it's for. It would be dirt cheap and plenty fast. A early 90's C64...

Another bonus would be for WDC that would allow them to maybe introduce 65832 and 65032 chips eventually.

[WolfToTheMoon]

It's not compatible enough. Both for timing and the instruction set.

it was compatible enough for Apple II GS...
 

To make it faster than an a500 would require faster memory than an a500. It wouldn't have been cost effective enough

It doesn't need to be faster than A500, just to be a good enough upgrade on C64/C128 and allow people to use their existing C64/C128 software...

I think everyone knew these machines were dead ends so having them
cannibalize sales of the 16/32 bit machines would have been
shortsighted and really wasted development time.

I don't see why they would be dead ends... WDC had a 32 bit version of the 65xx ready and much of the Eastern Europe and the rest of developing countries had trouble affording PCs and even low end Amigas/Ataris well in to the 90s... I got my first PC, a 486/50, somewhere around 97'... and it was used... up untill then I still used my C64.

The C64 was still selling like crazy in 1990, while the A500 had dropped
below the 1000 DM/350 UKP mark by then. Between these two, there
was simply no space for another machine. The C128 had been
discontinued for that very reason, despite selling better than the A500.

I'm talking abour a successor machine to the C64/C128, not something to slot between C64 and A500.

[WolfToTheMoon]

One other area that C= sadly neglected was the mobile market. I would imagine that a cheap 65xx or 65xxx design would have sold very well(LCD was rumored to have had 15 000 orders on launch, before cancellation)  and that the 16 and 32 bit 65 versions would be great for cheap PDAs later.


I always believed it was a big mistake that C= never persued further 6502 development as they had great talent in MOS technologies - the future Athlon K7 designer worked on C65's CPU. Browsing the web, I have found indications that Tramiel pretty much killed any serious development shorty after aquiring MOS - some former engineers claim that a 32 bit version of the 6502 was being in the works at the time. This could have had major implications for C= as it was possible that it would have been chosen by, for instance, Apple for the Mac and further evolution of the II series...