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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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Old 12th May 2015, 10:08 pm   #41
woodchips
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Default Re: Microprocessor favourites?

If you want to try something different get a Motorola DSP56000. Weird instruction set compared to ordinary processors, but doesn't it move! 10MHz and possibly 3 instructions per clock.
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Old 12th May 2015, 10:47 pm   #42
Karen O
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Default Re: Microprocessor favourites?

This is an interesting thread.

My greatest affection has to be for the humble SC/MP - the processor on which I first learned to program in machine code. It still features in my hobby activities today, albeit using a PIC emulator I created.

When it comes to 'serious' processors, well then I'd have to say the 6809. This was a joy to use but sadly too late on the market.

I see the Z80 in the same light as VHS - commercially successful but not the most elegant of processors with much of its instruction set stuffed into the spaces left by the 8080.

More recently, and against advice from colleagues and other hobbyists, I got into the PIC 12F and 16F series (14 bit instruction types). The instruction set of this microcontroller seems very strange at first with its reversed destination policy for results of operations, but it has enabled me to write some very efficient real time programs, including a TV standards converter of sorts.

I guess I'm a sucker for the small and humble. I always seem to come away from rallies with things that no one else wants
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Old 14th May 2015, 9:21 pm   #43
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Default Re: Microprocessor favourites?

I started age 18 with Z80, a home built Nascom 2 in early 1980 bought by my father from Electrovalue. Assembled in the kitchen with a pan boiling on the stove to eliminate static Interestingly this computer had an 8K Basic compiler from a company called Microsoft before many people had heard of them. Taught myself assembly programming a year later using Zeap assembler. That helped me to get my first job where I did some 8080 (Intel dev system), Z80 and later 8031, 8035, 8042 and 6801. Changed my job and did some more projects with ceramic 6801 (about £30 each at the time). Career wise I moved away from programming, but returned to it doing hobby and weekend work using Z80 (spectrum and homebrew systems) 8051 and some Philips and Atmel derivatives eg At89C2051 using C language. Tried PIC a few times, disliked the instruction set. Used LET basic once with some success.
Since then mainly use AVR series and C with AVR Studio.
My favourites are :
Z80 - because it had good 16bit registers ops and some powerful instructions for its time eg LDIR
6801 - because one of the first with internal EPROM and Mul and Div instructions IIRC
Atmel 8051's as they had flash ROMs - saved loads of time without that UV eraser...
AVR - Small package options, Compact instruction set for Assembler and great with C language

Most fun was had cramming the code for Rust RCU04 (google it) radio remote control into the original AVR with just 512Byte ROM. zero bytes left unused, even the E2PROM memory was full with data

Last edited by unitelex; 14th May 2015 at 9:29 pm.
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Old 15th May 2015, 8:54 am   #44
lesmw0sec
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Default Re: Microprocessor favourites?

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Originally Posted by unitelex View Post
Career wise I moved away from programming, but returned to it doing hobby and weekend work using Z80
Oddly, I took the reverse path! Was always a hardware man and then started using Z80 based stuff. Went on to the higher languages. I could see that hardware design was entering in to the simulator & PLA area, which I did not find interesting, so decided to go into the software only business. It was only upon retirement that I resumed work on hardware and radio.

Les.
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Old 27th Jun 2015, 8:25 pm   #45
TonyDuell
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Default Re: Microprocessor favourites?

Like some others, I came to computing from electronics. Unlike some others, I never really took to programming, much prefering the hardware side.

I started out on the SC/MP (in an MK14), then went Z80. Never really liked the 6502. But when I saw the 6809 I fell in love with it. That was easily the nicest of the 8-bitters. A very orthogonal instruction set (if you can do something with one addressing mode, you can do it with any sane addressing mode, etc) and a great set of addressing modes (it's the only 8 bitter I have used to have long relative branches, relative subroutine calls, and program counter relative addressing for data, meaning you
can write totally position independant code).

It's a pity this thread is only for microprocessors... You see my favorite machine code has to be PDP11. But that's too high a level for me, really. My favourite binary programming code has to be PERQ microcode...
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Old 28th Jun 2015, 1:39 pm   #46
SiriusHardware
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Originally Posted by TonyDuell View Post
Like some others, I came to computing from electronics. Unlike some others, I never really took to programming, much prefering the hardware side.
Nice to hear from a fellow MK14/ SC/MP owner / (ex owner?). Mine (still in my possession) gave me my first experience of programming.

My history is the same, but career wise I think wish I had swung in the opposite direction since, while demand for programmers and IT specialists only seems to continue to rise, demand for hardware technicians who can fault find / repair at component level continues to diminish.

I often describe myself as a 'Blacksmith of the modern age' - skilled at doing something which very few people actually need me to do any more. The only reason I still do it is because I love doing it.

Although I do a few hours of microprocessor programming per month in the context of making one-off test rigs, data analysers and controllers which directly aid me in my job as a hardware technician, I have not done it often enough for long enough to make me a skilled operator in this area, so there's not much prospect of my being employed as a programmer now.

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It's a pity this thread is only for microprocessors... You see my favourite machine code has to be PDP11. But that's too high a level for me, really. My favourite binary programming code has to be PERQ microcode...
As the originator of this thread I can say that I would not to too horrified if you wanted to use it to talk about PDP11 - nowadays I tend to try to choose thread titles quite carefully so as not to make their scope too exceedingly narrow, rather than risk losing some potentially interesting responses due to their being thought too OT for the thread. Of course, there's nothing to stop you from starting a new thread devoted to PDP11...
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Old 28th Jun 2015, 2:36 pm   #47
TonyDuell
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I still have my MK14, in fact I unpacked it last week after the house move last year. Alas I removed the SC/MP years ago for a project, then had a 5V PSU 'problem' (it leapt to about 15V). At the time I didn't bother to get a replacement, I was moving on to the Z80, and now of course the SC/MP is very hard to find and expensive. I have a few of them in commercial devices, though... Let me see... Wasn't 'C4' LDI (Load Immediate), '07' CAS (Copy Accumulator to Status register) and '90' an unconditional relative jump. It's been a long time...

I know what you mean about jobs. I wish I had taken to programming, but really it never excited me at all. And like you, I can do (and love doing) component level repair on complex-ish systems. Nobody will pay me to do it, but it's a hobby..

I'll miss out the boardswapper rant. Suffice it to say that in my experience replacing random parts causes more problems than it solves. It gets worse. I have seen factory repair manuals (if I say what, I'll be thrown off the forum, PM me if you like) that give
proper diagnostic techniques that nobody seems to follow. ARGH!

Incidnentally, is the Sirius part of your user name anything to do with an obscure 8088 machine with a very odd disk system designed by Chuck Peddle (?Spell). If so, I have one, and know it well.... Having 6522s (6 of them) in an 8088 machine rates as being a little strange.
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Old 28th Jun 2015, 2:55 pm   #48
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Default Re: Microprocessor favourites?

The first real microprocessor I got involved with at work in the '70s was the Intersil IM6100, which was basically a CMOS PDP-8. This was all based on 12-bit words and needed 12-bit wide RAM and EPROM (originally 1702A chips and 1.5 devices wide). The 6100 could be bought in military specs and withstood quite a bit of radiation - useful when building reactor protection instrumentation. I can still remember doing the coding in assembler.

Eventually the processors became obsolete and the whole lot was redesigned round MC68000 chips. I think by then I had figured out I was better at engineering management anyway.

Mike
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Old 29th Jun 2015, 12:29 am   #49
SiriusHardware
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Originally Posted by TonyDuell View Post
I still have my MK14, in fact I unpacked it last week after the house move last year. Alas I removed the SC/MP years ago for a project, then had a 5V PSU 'problem' (it leapt to about 15V).
:Wince: I hope you manage to find a replacement SC/MP. Mine is still working, although, like many survivors, it lacks the original keypad which was replaced because it was so bad. There is a separate thread about it, including a link to a youtube video of it running, elsewhere in this 'vintage computers' subforum.

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I'll miss out the boardswapper rant.
It's just the way things are going. It's been years since anyone was prepared to pay a technician to fix domestic electronics, so for about 20 years now I have been working in the industrial / service sector, the ten most recent for a small British firm which still makes its own electronics, including building the PCBs on the premises.

When I started there the microprocessors / microcontrollers and other devices being used were predominantly DIP devices, typically the 8031 with external EPROM and the 89C52 with built-in Flash ROM, along with a wide assortment of PIC family devices, but in the interim SMD devices have almost completely taken over and we are now at the point where some of them don't even have visible pins on the edge of the device which a human being can solder. Some of the resistors we are now using are like grains of sand, so small that we can barely see them, never mind solder them.

As this type of technology becomes dominant, it will become ever more difficult / time consuming to fix faulty PCBs and more cost effective to discard them and replace them with new. We aren't at that stage where I work yet, but I would be very surprised if my job still exists in five years' time.

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Incidentally, is the Sirius part of your user name anything to do with an obscure 8088 machine...
No, but I remember them. My 'Handle' was originally chosen when I was frequenting forums about one of my other nerdy interests, steam locomotives, so I'm afraid 'Sirius' is just a quirky / silly (you decide) distortion of 'Serious'.
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