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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
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21st Aug 2020, 12:22 pm | #1 |
Banned
Join Date: Nov 2014
Location: Derry, Northern Ireland, UK.
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Motorola 6800 architecture
I learned assembly, C, C+ on this one at Uni, but then moved to on to Pentium.
Are they still of any use on a modern emdedded system ? |
21st Aug 2020, 4:24 pm | #2 |
Octode
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
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Re: Motorola 6800 architecture
Did you mean the 68000 which was 16/32 bit or the original 8 bit 6800?
I think the 6800 would only be found in older systems, as it was replaced by the 6802 and 6809 which were easier to use or added more instructions. 68000 was also replaced by the 683xx series for use in embedded systems. This included the Ford EEC IV engine management system and early Motorola GSM mobile phones, both of these made use of the TPU that was included in the 683xx. |
21st Aug 2020, 8:23 pm | #3 |
Hexode
Join Date: Oct 2014
Location: Wiltshire, UK.
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Re: Motorola 6800 architecture
I have never come across a C compiler for the 6800 leave alone a C++ compiler. The 68000 was extensively used in early Unix workstations from Sun and others so did enjoy high level language support. Tektronix used 6802s and possibly 6800s insome of the 7000 series plugins that had GPIB interfaces (7A16P, 7B90P and7912AD).
Regards, Roger |
21st Aug 2020, 8:43 pm | #4 |
Nonode
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Re: Motorola 6800 architecture
C and C++ are very much still useful in embedded systems. In fact they're probably the dominant languages in that sphere, and will be for some time, I expect.
The 6800 architecture doesn't turn up much any more, but the 68000 still exists - the Motorola 'Dragonball' chips were popular for a while and I think some derivatives of them are still in use. Linux still supports the 68000. I have it running, just about, on an Apple Macintosh SE/30, which uses a 68030. There is some satisfaction to be had from running a 2020 operating system on a 1989 computer! Chris
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27th Aug 2020, 5:00 pm | #5 | |
Triode
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Re: Motorola 6800 architecture
Quote:
We use a MITEL VOIP system at work. It recently required some maintenance and a Technician who specialised in MITEL came in to check it. The Boot sequence actually referred to starting a Motorola 68000 Emulator. :O It turned out that the initial MITEL VOIP servers utilised Motorola 68000's, possibly in a DSP role. (Not certain about the DSP aspect, so don't quote me on it.) |
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27th Aug 2020, 6:28 pm | #6 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
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Re: Motorola 6800 architecture
Indeed C is widely used (I can't comment on C++). Almost all of the modules that I had dealings with in my industry were programmed with C. There was a specific subset that was allowed to be used, called MISRA, since a couple of C constructs were considered not reliable. For example pointers weren't allowed (I believe because it's too easy to get a corruption). The semi-standardisation means that the OEMs buying modules from tier 1 suppliers can insist that the tier 1's use standard libraries for things like the communication layer, to ensure that the networks don't have 'funnies' due to interpretation. And yes it happens!
Many modules for volume production in my (ex) industry are based on microchip PIC devices. Microchip themselves provide a development environment and debug hardware, with free C compilers (which is one of the main reasons they are so popular with developers). Not only that, but I used C a lot with things like Arduino, for producing one off test equipment. A colleauge also used it with more complex kit of a similar base, to produce some even more complex one of test kit for specific development, test, or production test requirements. Further, it's the basis of some other 'languages' such as something called CAPL which is very specifically used for programming in an environment for testing and validating specific communication networks. If you know C, you can learn CAPL. And if you can program in CAPL there will be a queue of people wanting your skills! (Or at least that has been my experience). So. 6800 / 68000 architecture, I have no idea, but being able to programme in C is very much useful, and valuable today. Being a high level language it's largely platform independent. |
29th Aug 2020, 9:13 am | #7 |
Dekatron
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Location: Newcastle, Tyne and Wear, UK.
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Re: Motorola 6800 architecture
Java strikes me as another C-like language. I have to admit I used to hate 'C' with a passion, describing it as a 'write only' language because unlike languages such as BASIC which are very human-readable, 'C' allows so many shortcuts as to render itself almost unreadable.
It was PICs which finally got me to try 'C', because of the very odd quirks which the early generation of PICs had - things like not being able to have subroutines or lookup tables lying across a page boundary. 'C' compilers for PIC just make all of those problems go away. Having since managed to burn through that barrier of dislike, I'm now quite happy to programme PICs and other systems in Arduino in 'C' but I still tend to write the code longhand, so for example I will write variable=(variable+1) rather than variable++ because the first example is easier for a human reader to understand and if the compiler is any good, it will generate the same code. |
29th Aug 2020, 9:48 am | #8 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
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Re: Motorola 6800 architecture
The 68000 is a dream chip for C compilers due to the rich register set. The 6800 was one chip I never actually programmed although the 6809 which featured on the Dragon 32 made here is Wales was an eye opener of a chip after my work with the Z80 (and 6502) for its orthogonal instructions and amazing flexible addressing.
I still have a soft spot for the 6809 and I suppose why I loved the 68000 - which I first had a chance to program in in its 8 bit variant the 68008 in the QL I was lucky enough to collect from Sinclair Research early with a huge NDA! It was funny about 7 of us sat on the train back to London all with the same large Jiffy bags from various companies unable to talk to each other... Of course as with others I went on to use the chip on the ST and the Amiga but, that was the point where we really began to pick up using C for major work for speed and flexibility and the ability to port over to the 8086 in the IBM PC. I think beyond that chip architectures have been optimized to provide what high level languages need in real terms. Even modern assembly is in large part giant Macros and library linking... |
29th Aug 2020, 9:49 am | #9 |
Octode
Join Date: Jan 2003
Location: Ware, Herts. UK.
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Re: Motorola 6800 architecture
C and C++ are very much still in use in embedded systems, operating systems, large scale applications, mobile phones etc. I'd say that just about every contemporary commercial device containing a microprocessor from a PIC upwards will be running at least some compiled C code.
I've used one or the other or both in every job I've had since 1984. John |
30th Aug 2020, 10:45 pm | #10 |
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Re: Motorola 6800 architecture
I think it important to remember that C was conceived as a 'high level' alternative to assembler. You could write an OS e.g. Unix with reasonable runtime efficiency in C.
C was never rigorous, nor was it meant to be. |
1st Sep 2020, 5:56 pm | #11 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
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Re: Motorola 6800 architecture
That's true. Which is why for some uses there is a subset of constructs which can be used, for example MISRA. That isn't meant as a criticism of C, more that it was becoming very widely used, and some people didn't understand the potential issues of using it in certain situations.
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