Timeline for What limited the use of the 6809 CPU in personal computers?
Current License: CC BY-SA 3.0
20 events
| when toggle format | what | by | license | comment | |
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| Jul 28, 2021 at 7:05 | comment | added | cup | @MarkRansom It is just a different mindset, similar to Data General. I found the indexing difficult because of the auto increment. It is OK if you're coding in it all the time but when you have to switch between 8080, 6802, 6809 and Prime Assemblers, switching mindsets gets difficult. | |
| Jul 28, 2021 at 0:59 | comment | added | Mark Ransom | @cup I think the 6809 was the most elegant 8-bit processor I had the joy of programming for. Not sure why you found it difficult. | |
| Sep 12, 2020 at 1:07 | comment | added | Yuhong Bao | Some history of 6800 and 6502 worth mentioning: en.wikipedia.org/wiki/MOS_Technology_6502#History_and_use | |
| Jun 18, 2018 at 0:23 | comment | added | Jules | @JerryCoffin "their primary failure was in adapting to differences in marketplaces (e.g., people who used Windows phones liked them a lot--but MS never "got" how to sell into that market)" -- this is true... and here's a bit of history that a lot of people don't spot: the most popular web site for discussions of development on Android phones is xda-developers.com, but almost nobody ever notices that the "XDA" referenced in the site URL was an early Windows CE based smartphone... they had an early lead in developer mindshare, but lost it to Android because of the more open environment there. | |
| Feb 21, 2018 at 23:12 | comment | added | Johann Klasek | Also to mention that the 6809 architecture has an excellent addressing mode set with a register layout which leads finally to more compact code even the cycle count is sometimes greater for equivalent instructions compared to a 6502. Superior for pointer oriented stuff, OS implementation, common techniques for compiler-based languages (which was one of several design goals of this CPU). Especially for the stack-based programming language like Forth a 6809 was regarded as the ideal choice. | |
| Feb 21, 2018 at 18:21 | comment | added | Jerry Coffin | @Blrfl: From a hardware viewpoint, Microsoft has adapted to multiple architectures just fine--somewhere in my garage I'm pretty sure I still have discs for Windows NT to run on x86, Itanium, MIPS, DEC Alpha, and PowerPC. I'd say their primary failure was in adapting to differences in marketplaces (e.g., people who used Windows phones liked them a lot--but MS never "got" how to sell into that market). | |
| Feb 21, 2018 at 17:53 | comment | added | Blrfl | @JerryCoffin True. Having been in this since about the time of the 8088's debut, I'm not convinced that the yoke of eternal backward compatibility didn't set the industry back. Motorola wasn't saddled with it, and the improvements they made in later versions were, I thought, positive. The fact that in 2018 the ARM box on my shelf can run the same stuff as my x86 box on my desk or the S/390 in the fishbowl with only recompilation says we've come far enough that it's no longer really necessary. Microsoft's failure to adapt to multiple architectures is, IMHO, their problem. | |
| Feb 21, 2018 at 17:25 | comment | added | Jerry Coffin | @Blrfl: I think that's over-simplifying quite a bit. Motorola made some pretty major changes in how the MMU worked in the 68040 vs. 68030. Then they changed things again in the 68060. Yes, it was possible to detect the processor and use code that worked on each. It's still a lot different from Intels where code written for a 386 in 1987 will still work just fine on a 2018 Skylake X. | |
| Feb 21, 2018 at 17:06 | comment | added | Jerry Coffin | @traal: I can (but it's software I wrote that was intended to figure out whether the 386 it was running on was an Intel or an AMD, so having to update it to work properly on a 486 didn't surprise me). | |
| Feb 21, 2018 at 15:21 | comment | added | snips-n-snails | @Blrfl Can you think of any software that runs on a 386 but not a 486? | |
| Feb 21, 2018 at 14:05 | comment | added | Blrfl | @traal That's a deficiency in Amiga Unix, not the processor. The M86K family had a long, healthy life in a number of general-purpose computers (early Suns and Macs) and had considerable success in the embedded space as a standalone CPU. Despite having been discontinued by Motorola in 1994 after a 15-year run, compatible versions continue to be available as VHDL for use in FPGAs. | |
| Feb 21, 2018 at 10:00 | comment | added | JeremyP | @traal By that time, the PC with the x86 architecture had already taken over the the world of PCs. | |
| Feb 20, 2018 at 19:01 | comment | added | snips-n-snails | @JeremyP Amiga Unix can only run on a 68030 CPU because subsequent CPUs were not fully backwards compatible. | |
| Feb 20, 2018 at 14:25 | comment | added | Edward | Yes, cost!! Example: a Jameco ad from a September 1984 issue of BYTE magazine lists the 1MHz MC6809E at $14.95, compared with 2MHz MC6502A at $6.95, 4MHz Z80A at $4.49, and P8085A at $4.95. Same ad also lists 5MHz 8086 at $24.95. | |
| Feb 20, 2018 at 9:29 | comment | added | JeremyP | @traal The 68000 was wildly successful. It didn't contribute to Motorola's demise in any way. | |
| Feb 20, 2018 at 4:44 | comment | added | robert bristow-johnson | well, for electrical engineering students just learning microcomputer hardware and software and DSP, the 6809 was sexy. it was the first microporicessor CPU with a multiply instruction that i am aware of. and the orthogonal addressing modes with post-increment and pre-decrement were also quite cool. | |
| Feb 19, 2018 at 8:45 | comment | added | cup | I just found the 6809 difficult to program. It had these combination commands that required an extra level of thinking, very much like Data General Assembler where you had to do a couple of commands in parallel. | |
| Feb 19, 2018 at 6:28 | comment | added | snips-n-snails | Also the Motorola 6809 was not a drop-in replacement for the MOS 6502 or even the 6800. Later, the 68000 line experienced similar backwards compatibility issues that Intel's x86 line never had, and I think this contributed to Motorola's demise. | |
| Feb 18, 2018 at 22:42 | history | edited | Jules | CC BY-SA 3.0 |
added 16 characters in body
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| Feb 18, 2018 at 22:36 | history | answered | Jules | CC BY-SA 3.0 |