11–20 of 70 posts
Zilog could get a bigger market share. Still remember those times programming in Z80 machine code. It was much more flexible and convenient versus 8080. You can find Zilog in embedded systems, they are not dead at all.
https://z80kits.com/product-category/basekits/
I have so much moe for the various post-Z80 chips Zilog made that people think failed in the marketplace but are still around and perfectly viable for applications that don't need 32-bit https://en.wikipedia.org/wiki/Zilog_eZ80 But the thing is that you keep getting dragged kicking and screaming to ARM because even if it is boring it is capable, affordable and everywhere.
The latest round of STM32G0 is about $1 in quoted price before you start haggling. TI is launching a $0.40 (!) ARM micro soon. A modern toolchain, an ALU that doesn't suck, and a ton of ecosystem support are genuine improvements over z80. It's just the new default in the same way that z80 was a default (though less so, I grant). And I say this as someone who still knows z80 opcodes from high school programming TI cal…
From the wiki link of the z8000 there is a curious bit of Commodore history I never knew of: https://en.wikipedia.org/wiki/Commodore_900 C. had a pretty good deal with zilog, but they pissed it away for maybe not very good reasons.... Had things gone different C900 and the like might've been there instead of the Amiga.
The thing that I remember was that the Z8000 had some pretty complex addressing modes.
To support this approach, the architecture would be based on segmented addresses.”
I don’t see how that follows, given the example of the 6507. https://en.wikipedia.org/wiki/MOS_Technology_6507
“The 6507 (typically "sixty-five-oh-seven" or "six-five-oh-seven") is an 8-bit microprocessor from MOS Technology, Inc. It is a version of their 40-pin 6502 packaged in a 28-pin DIP, making it cheaper to package and integrate in systems. The reduction in pin count is achieved by reducing the address bus from 16 bits to 13 (limiting the available memory range from 64 KB to 8 KB) and removing a number of other pins used only for certain applications.”
The instruction set of the 6507 can address 64kB of memory, but it lacks connections to the outside world to actually use its full address range (it might even be possible for a hardware hacker to open up a 6507 and add those extra pins, depending on how much the 6507 internals differ from that of the 6502)
Earlier quoted context omitted.
The latest round of STM32G0 is about $1 in quoted price before you start haggling. TI is launching a $0.40 (!) ARM micro soon. A modern toolchain, an ALU that doesn't suck, and a ton of ecosystem support are genuine improvements over z80. It's just the new default in the same way that z80 was a default (though less so, I grant). And I say this as someone who still knows z80 opcodes from high school programming TI cal…
I saw a tweet once that went something like, "Mankind strayed from god when we invented the IC", and some days I feel that. Economies of scale crush everything, including our nerdy fondness for particularly elegant ISAs.
I recall with considerable fondness those ISAs that could be understood in ultimate detail by a simple human - the monolithic supercomputers like the Cray 1.
Does anyone have the history for why number of pins was such an important consideration (not just for Zilog, Intel too)? Was it really that much more expensive to make a 64 pin package than a 40 pin one?
The 8086/8088 multiplexed the address and data busses to get the pin count to 40. Which wasn't bad when using DRAMs since they're also multiplexed. Again to save cost.
Advantage of the 8088 was the 8 bit data bus. So you only needed 8 DRAM chips. Which was a big cost savings. And extra 16k of DRAM could be hundreds of dollars.
FTA: “One cheaper version would fit into a 40-pin package. This version would have its memory address sizes limited to 16-bits and so would only be able to use 64 KB of memory. A more expensive 48-pin version would have access to a 23-bit or 8 MB address space. To support this approach, the architecture would be based on segmented addresses.” I don’t see how that follows, given the example of the 6507. https://en.wik…
Zilog could have gone down the 6507 style route, I guess, but the Z8002 would have been more expensive to produce.
So use of the word 'support' is really 'in support of a cheaper 16 bit address / 40 pin version' where savings are made not only on packaging but on the die.
I have so much moe for the various post-Z80 chips Zilog made that people think failed in the marketplace but are still around and perfectly viable for applications that don't need 32-bit https://en.wikipedia.org/wiki/Zilog_eZ80 But the thing is that you keep getting dragged kicking and screaming to ARM because even if it is boring it is capable, affordable and everywhere.
The latest round of STM32G0 is about $1 in quoted price before you start haggling. TI is launching a $0.40 (!) ARM micro soon. A modern toolchain, an ALU that doesn't suck, and a ton of ecosystem support are genuine improvements over z80. It's just the new default in the same way that z80 was a default (though less so, I grant). And I say this as someone who still knows z80 opcodes from high school programming TI cal…
And yet many cheap electronic devices will continue to be built and sold with 4-bit microcontrollers because 32 bit is overkill for those use cases and $0.40 is too expensive when 4-bit dies cost $0.05 or even $0.01, and $0.35 in savings is huge in high enough volume.
You won't see any new products developed in the west using such microcontrollers but they're still alive and kicking and there's still developers for them in Asia.