Questions tagged [m68k]
For questions about processors in the Motorola 68k (68000 series) range. Commonly used in Amiga, Atari ST, Macintosh, Sinclair QL and Sharp X68000 computers.
25
questions
10
votes
2
answers
1k
views
What file format was used for binary executables on Motorola 680x0 Macintoshes?
Current macOS binary executable files use a format called "Mach-O" and prior to that there was the PEF "Preferred Object Format", and Wikipedia says "It was optimised for RISC ...
- 6,938
10
votes
3
answers
2k
views
Why did Steve Jobs choose the Motorola 68030@25 MHz for the first NeXT Computer in 1988 and not an Intel 80386DX@25 MHz processor?
Was the reason because he knew the 68K from the Macintosh, or were there other reasons that spoke in favor of the 68030 and the additional 68882 floating-point coprocessor?
The i386, along with a 387 ...
- 1,068
10
votes
1
answer
1k
views
MC68000: address error in initial PC
After an MC68000 processor is released from reset, it fetches the initial stack pointer and initial program counter from the vector table at addresses 0-3 (for the SP) and addresses 4-7 (for the PC).
...
- 905
14
votes
1
answer
2k
views
GCC to make Amiga executables, including Fortran support?
I have been compiling some command line programs to run on the classic Commodore Amiga. I started with GCC on WinUAE which worked but I realised I didn't have the understanding of the memory stack and ...
- 143
4
votes
3
answers
266
views
Mac OS Classic install error "the installer document is unusable for installation [...]" (original disks message)
Attempting to upgrade Mac OS Classic 7.5.0 to 7.5.3 via floppies that have been tested successfully on a Performa 460... but things fail ominously on my IIsi with "This is not the correct "⟨...
- 365
4
votes
2
answers
249
views
Drive icons for LaCie Tsunami
I am restoring a LaCie Tsunami 240 external disk for the Macintosh. I found a replacement Quantum LPS240 and the hardware side is well on its way.
This drive displayed a custom icon in System 7 (a ...
- 365
4
votes
1
answer
552
views
Were any 680x0 features specifically requested by a customer?
The Motorola 680x0 processor family was used in a variety of systems, including Apple Macintosh, Atari ST, Commodore Amiga, Sharp X68000, and Sinclair QL systems. Had any of these customers wanted a ...
- 16.5k
2
votes
3
answers
932
views
M68k Big Endian to Little Endian
I'm trying to write a binary file using vasm68k_mot (Motorola 68k) writing File-Size and File-Offset everything goes well, except that M68K is Big-Endian, there's a way I can change to Little-Endian ...
- 39
5
votes
1
answer
255
views
MC68030: does execution resume during or after cache burst refill?
The MC68030 processor is equipped with dual 256-byte instruction and data caches as well as a "burst" mechanism used to quickly load a cache line from RAM or L2 cache controlled by the ...
- 905
30
votes
1
answer
4k
views
Why are the later revisions of the Motorola 68060 heavily sought after by Amiga fans?
I have come across a few sources online in forums and on YouTube information related to using the Motorola 68060 in Amiga accelerators and the difficulty in sourcing genuine late revision parts. ...
- 403
3
votes
1
answer
254
views
Porting of software from the m68k family architecture to the DEC VAX
I am looking for impressions, memoirs, articles, guidelines - everything that is possible about the unusual direction of software migration. I am interested in non-Unix related code, and preferably ...
- 2,201
10
votes
3
answers
2k
views
What performance increase did an Amiga typically get with an FPU?
After seeing this question, I reminisced about how my old Amiga 2500/030 had a 68882 FPU unit. I recall that the Amiga's floating point routine library was smart enough to detect if you had an FPU or ...
- 16.4k
22
votes
7
answers
5k
views
Why were there no 32-bit versions of 65xx CPUs, or 64-bit versions of m68k CPUs?
I don't understand why Western Design Center made the 65816 a 16-bit upgrade to the 6502 but Commodore Semiconductor Group/MOS Technology didn't make their own variant & why neither company made ...
26
votes
6
answers
10k
views
Why are old CPUs like MOS Technology 6502 and Motorola 68000 considered better for real time systems applications than modern x86 based CPUs?
Reading the Wikipedia article about real-time computing, I found written that:
Once when the MOS Technology 6502 (used in the Commodore 64 and Apple II), and later when the Motorola 68000 (used in ...
- 563
6
votes
2
answers
606
views
Were any M68000 systems capable of generating a "spurious interrupt"?
When an interrupt occurs on a Motorola 68000-family processor, it enters an interrupt acknowledge state, which continues until one of three signals are asserted:
An external device places the ...
- 16.5k