EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: technix on September 10, 2016, 06:07:57 pm
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Some seller in my local electronics store is eagering to sell off her years old stock of MC68000 (in DIP-64) and 8086/8087 CMOS equivalents (in DIP-40.) I am itching.
I wonder if this is a good chance to invest in a DIY computer. Maybe I can create a DIY SBC that have 2x (or even 4x) i8086/i8087 sets? The same seller also have (and I have bought some) 61C512 SRAM so maybe I can run for full 1MB SRAM for the 8086? I think that modern 74HC chips are fast enough for 8MHz operation.
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I strongly suggest the M68K due to it's ease of programming. Though my small experiments with it, all it is is just 8 data registers and 8 address registers with a few extra registers like a program counter.
It's a CISC processor, which while require more commands to learn, can do more things like having dedicated multiplication addresses unlike the Z80 and other RISC equivalents.
Another thing to consider is that the i8086 is still being programmed for and used in modern computers (Albeit with a lot more bolted on) today, and thus has INDEFINATELY more things written for it and INDEFINATELY more hardware available to support it's use, however I am not sure how easy it is to program for.
I had an interesting idea for a 3 CPU M86K computer that uses one 68K as a video generator, one for peripherals and for multi threading, and another as a strictly processing related chip, with even further ideas for a fourth processor as a specialty graphics chip, but I never went anywhere with it.
You can ask 100 engineers and you all get different answers.
Z80 for simplicity
M68K for ease of programming and high capabilities
i8086 for more options.
All are great choices, but the M68K with it's hybrid 16/32 bit design would be my first choice.
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There were multiprocessor z80 machines (like the ZMOB, with 256 CPUs).
A lot of the complexity of building a computer in "the old days" was the support chips: timers, DMA controllers, peripherals. These days you could fit all of that into a single small, cheap CPLD or FPGA.
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There were multiprocessor z80 machines (like the ZMOB, with 256 CPUs).
A lot of the complexity of building a computer in "the old days" was the support chips: timers, DMA controllers, peripherals. These days you could fit all of that into a single small, cheap CPLD or FPGA.
That is the best thing I've ever seen. It's like the precursor to Raspi supercomputers.
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Tell her to learn how to sell on eBay if she sells surplus electronics. Trying to sell that stuff locally is an exercise in futility, or at least slow sales at lower prices. eBay's premium more than makes up for the better sales environment.
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Tell her to learn how to sell on eBay if she sells surplus electronics. Trying to sell that stuff locally is an exercise in futility, or at least slow sales at lower prices. eBay's premium more than makes up for the better sales environment.
With your services paid for in merchandise....? ;)
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Tell her to learn how to sell on eBay if she sells surplus electronics. Trying to sell that stuff locally is an exercise in futility, or at least slow sales at lower prices. eBay's premium more than makes up for the better sales environment.
Here "local" means Shanghai. One of the biggest cities in the world with just shy of 30 million people living here (including ones that is not registered, 14.5M registered residents. Mow much population does Switzerland have as a country?)
There have to be some market capacity if 3x a country's population is scrammed into a space within 1.5 hour of public transit and at about the same level of education.
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Tell her to learn how to sell on eBay if she sells surplus electronics. Trying to sell that stuff locally is an exercise in futility, or at least slow sales at lower prices. eBay's premium more than makes up for the better sales environment.
Here "local" means Shanghai. One of the biggest cities in the world with just shy of 30 million people living here (including ones that is not registered, 14.5M registered residents. Mow much population does Switzerland have as a country?)
There have to be some market capacity if 3x a country's population is scrammed into a space within 1.5 hour of public transit and at about the same level of education.
Please inform all those sellers from Shanghai and Shenzhen who are selling on eBay that I have bought from. They agree with me and disagree with you. You should enlighten them.
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Tell her to learn how to sell on eBay if she sells surplus electronics. Trying to sell that stuff locally is an exercise in futility, or at least slow sales at lower prices. eBay's premium more than makes up for the better sales environment.
Here "local" means Shanghai. One of the biggest cities in the world with just shy of 30 million people living here (including ones that is not registered, 14.5M registered residents. Mow much population does Switzerland have as a country?)
There have to be some market capacity if 3x a country's population is scrammed into a space within 1.5 hour of public transit and at about the same level of education.
Please inform all those sellers from Shanghai and Shenzhen who are selling on eBay that I have bought from. They agree with me and disagree with you. You should enlighten them.
And let's not forget about entry hazards of general online activity in China. And at least for that seller she is not really willing to use a computer at all.
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8087 CMOS equivalents (in DIP-40.)
how many chips are we talking about?
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Money will be best invested in any FPGA, that can emulate both with free IP core, Those legacy ic's are only for service on older stuff never for new design