Developers Try Again To Upstream Motorola 68000 Series Support In LLVM

[L_A_G]

Not sure if there's much of a point to this late into the twilight years of the Motorola 68k. Sure, derivatives are still being produced by NXP(who merged with Freescale, Motorola's semiconductor division after it was spun off, in 2015) for low power embedded applications, but so are Zilog Z80 and MOS 6502, yet you don't see mainline support for those anymore.

[adler187]

Not sure if there's much of a point to this late into the twilight years of the Motorola 68k. Sure, derivatives are still being produced by NXP(who merged with Freescale, Motorola's semiconductor division after it was spun off, in 2015) for low power embedded applications, but so are Zilog Z80 and MOS 6502, yet you don't see mainline support for those anymore.

That's because both GCC and LLVM are primarily C/C++ compilers and those 8-bit CPUs are excruciatingly difficult to write useful C compilers for. See https://retrocomputing.stackexchange...duce-poor-code Primarily these systems are targets for assembly, not C, though there is cc65 for the 6502 and sdcc for the z80 and others.

[Jumbotron]

That's because both GCC and LLVM are primarily C/C++ compilers and those 8-bit CPUs are excruciatingly difficult to write useful C compilers for. See https://retrocomputing.stackexchange...duce-poor-code Primarily these systems are targets for assembly, not C, though there is cc65 for the 6502 and sdcc for the z80 and others.

Quite right. Although there were certainly high level languages such as BASIC and PASCAL, even C, at the time, the old 8 bit and even the newer 16 bit CPU's such as the 68000 were more geared for assembly. Especially when you were trying to push as many pixels as you possibly could AND include game logic into a small low capacity cartridge designed for a game console like the Sega Genesis with only 64 kilobytes of RAM and a Motorola 68000 16 bit CPU running at the WHOPPING speed of.....7.14 Mhz, you really could only do that with assembly.

Imagine trying to pull off Ecco the Dolphin, or Earthworm Jim or Gunstar Heroes on a Sega Genesis using C. Gunstar Heroes, to this day, is still a marvel of "Bullet Hell" on the Genesis. All with only 64 k and a 16 bit CPU running at 7.14 Mhz. Mega....not GIGA hertz. < hat tip and golf clap to those early programmers >

[edwaleni]

The last Motorola 68k I worked with was the original Cisco routers. The MGS, AGS and AGS+ all ran the Motorola CPU's. I asked the engineers why the Motorola? They were all Apple fans and thought that was the best place to start. Those were the days replacing CPU boards before flash came along. It was like working with a Heathkit. Setting jumpers before inserting the board into the backplane.

[danmcgrew]

Not sure if there's much of a point to this late into the twilight years of the Motorola 68k. Sure, derivatives are still being produced by NXP(who merged with Freescale, Motorola's semiconductor division after it was spun off, in 2015) for low power embedded applications, but so are Zilog Z80 and MOS 6502, yet you don't see mainline support for those anymore.

Not sure why you think a comparison between the MC68xxx and the Z80 / 6502 is even---remotely---a valid one.

Are you, at all, aware of the architectural---hardware---, and software---instruction-set and memory-referencing-capability---differences between the ONE, and the other two which are not even in the same league?

I will not say anything about the comparison of apples to oranges. Promise.

[bridgman]

Looks like the article has been updated and now reads very cleanly.

For a long time a Motorola 68010 or higher plus a paged MMU was pretty much the standard for Unix minicomputers and workstations. The 68010 brought recoverable page fault support plus a few other changes to support virtualization, and IIRC most of the changes after that focused on performance.

[L_A_G]

Not sure why you think a comparison between the MC68xxx and the Z80 / 6502 is even---remotely---a valid one.

Way to totally miss the point... I said that they're the same from the standpoint of what they're used for; Very low power embedded applications. The sort of applications where even most ARM cores are too advanced and power-hungry.

Sure, some of the older Roombas and other "higher-power" embedded applications may have used them years and years ago, but those applications have long since moved almost exclusively to ARM-based SoCs. The 68k series now only really exists in the same very low power space as the Z80 and 6502.

[onicsis]

Sure, some of the older Roombas and other "higher-power" embedded applications may have used them years and years ago, but those applications have long since moved almost exclusively to ARM-based SoCs. The 68k series now only really exists in the same very low power space as the Z80 and 6502.

https://www.borntoengineer.com/z80-collapse-os-post-apocalyptic

https://news.slashdot.org/story/19/10/08/2036204/collapse-os-is-an-open-source-operating-system-for-the-post-apocalypse

[L_A_G]

...

Ok... So somebody made a basic OS in their spare time that'll run on a Z80? Is that supposed to be impressive? Gary Kildall created the first version of CP/M for the Intel 8080 way back in 1973 and the Z80 is a heavily upgraded derivative of it.

[spirit]

Yep. The final CPU in the m68k series was the 68060 released in the mid-90s. By then, Apple had already decided to switch to the PowerPC line of CPUs.

Don't forget the "new" 68080 made with an fpga for the new amiga vampire v4 in 2019 ^_^

https://www.youtube.com/watch?v=kbzi6Ma5pzI

Amiga will never die !