5 ms·

Famous? Are you referring to performance or just clock frequency? The Z80 takes more cycles to do the same operation as the 6502, but it also (typically) had a

by andars 10y ago

Famous? Are you referring to performance or just clock frequency? The Z80 takes more cycles to do the same operation as the 6502, but it also (typically) had a higher max clock frequency, mostly making up for it.

qwertyuiop924 10y ago
I was referring to the fact that a 1MHz 6502 could match a 4MHz Z80. >but it also (typically) had a higher max clock frequency, mostly making up for it. That used to be true. It is no longer true nowadays, so 65C02 beats the Z80 speed-wise.
- cmrdporcupine 10y ago
  Except Zilog came out with successors to the original Z80 that were far more cycle efficient. For example the eZ80, which can clock up to 50mhz.
  - avhon1 10y ago
    Not exactly "more cycle efficient", just more modern manufacturing processes. There are also 6502s available for up to 200 MHz. They are not easily available to hobbyists, though - the modern DIP modules are only guaranteed up to 20MHZ, but they can be run at 25MHz.
    - vanderZwan 10y ago
      It got a few more upgrades than just better miniaturisation: > The eZ80 has a 3-stages pipeline. Available at up to 50 MHz (2004), the performance is comparable to a Z80 clocked at 150 MHz if fast memory is used (i.e. no wait states for opcode fetches, for data, or for I/O) or even higher in some applications (a 16-bit addition is 11 times as fast as in the original). The eZ80 also supports direct continuous addressing of 16 MB of memory without a memory management unit, by extending most registers (HL, BC, DE, IX, IY, SP, and PC) from 16 to 24 bits. In order to do so, the CPU works in a Z80-compatible mode or a full 24-bit address mode. https://en.wikipedia.org/wiki/Zilog_eZ80 https://en.wikipedia.org/wiki/Zilog_eZ80 Note the pipelining, and the 24 bit ALU
    - cmrdporcupine 10y ago
      No I believe they actually made them more cycle efficient. And the eZ80 is available to hobbyists at the high clock rates if you're willing to do SMT.
      - mysterydip 10y ago
        Pardon my ignorance on the topic, but I've often wondered if it's possible to take one of these older CPU designs and "just" increase the address space and make the manufacturing process smaller (but otherwise leave the instruction set and architecture as-is) to create a modern bit version at a high clock rate for embedded or mobile use? Or is there a lot of "devil in the details" that has prevented such a thing from existing? It seems to me like upgrading one of these existing designs would be much cheaper R&D wise that you'd be able to compete very well on price for the IoT or other markets.
        qwertyuiop924 10y ago
        While it might (I don't know) be possible to make the manufacturing process smaller, you couldn't increase the address space without effectively rewriting the entire ISA. You could use bank switching or an MMU to increase the effective address space (allowing the machine to access more RAM than it can physically address), which was done even back in the day, on pretty much every machine. >you'd be able to compete very well on price for the IoT or other markets. Why do you think that the Z80 and the 6502 (and their derivatives) are still on the market? :-D
- Marazan 10y ago
  If a 1 MHz 6502 could match a 4MHz Z80 then that would mean a C64 could match a ZX Spectrum (which was clocked at 3.5 MHz) for performance in not sprite blitting scenarios. Which it couldn't. The spectrum smashed the C64 for speed of numerical operations, that's why the specrrum had lots of wireframe and solid filled 3d games and the C64 didn't. Like, Carrier Command on the Spectrum vs the abomination that appeared under the Carrier Command logo that appeared on the Commodore.
  - Graham24 10y ago
    It's been 30 years man, let it go.
    - Marazan 10y ago
      Never!
  - rasz_pl 10y ago
    sure http://www.hardcoregaming101.net/freescape/freescape.htm http://www.hardcoregaming101.net/freescape/freescape.htm nothing like a rose tinted glasses and fanboizm when it comes to membering those fluid 60fps full color FPS Spectrum games.
    - Marazan 10y ago
      Sorry, what were you saying? I fell asleep waiting for the C64 version of Total Eclipse to render a new frame

by andars 10y ago

qwertyuiop924 10y ago

I was referring to the fact that a 1MHz 6502 could match a 4MHz Z80. >but it also (typically) had a higher max clock frequency, mostly making up for it. That used to be true. It is no longer true nowadays, so 65C02 beats the Z80 speed-wise.

cmrdporcupine 10y ago
Except Zilog came out with successors to the original Z80 that were far more cycle efficient. For example the eZ80, which can clock up to 50mhz.
- avhon1 10y ago
  Not exactly "more cycle efficient", just more modern manufacturing processes. There are also 6502s available for up to 200 MHz. They are not easily available to hobbyists, though - the modern DIP modules are only guaranteed up to 20MHZ, but they can be run at 25MHz.
  - vanderZwan 10y ago
    It got a few more upgrades than just better miniaturisation: > The eZ80 has a 3-stages pipeline. Available at up to 50 MHz (2004), the performance is comparable to a Z80 clocked at 150 MHz if fast memory is used (i.e. no wait states for opcode fetches, for data, or for I/O) or even higher in some applications (a 16-bit addition is 11 times as fast as in the original). The eZ80 also supports direct continuous addressing of 16 MB of memory without a memory management unit, by extending most registers (HL, BC, DE, IX, IY, SP, and PC) from 16 to 24 bits. In order to do so, the CPU works in a Z80-compatible mode or a full 24-bit address mode. https://en.wikipedia.org/wiki/Zilog_eZ80 https://en.wikipedia.org/wiki/Zilog_eZ80 Note the pipelining, and the 24 bit ALU
  - cmrdporcupine 10y ago
    No I believe they actually made them more cycle efficient. And the eZ80 is available to hobbyists at the high clock rates if you're willing to do SMT.
    - mysterydip 10y ago
      Pardon my ignorance on the topic, but I've often wondered if it's possible to take one of these older CPU designs and "just" increase the address space and make the manufacturing process smaller (but otherwise leave the instruction set and architecture as-is) to create a modern bit version at a high clock rate for embedded or mobile use? Or is there a lot of "devil in the details" that has prevented such a thing from existing? It seems to me like upgrading one of these existing designs would be much cheaper R&D wise that you'd be able to compete very well on price for the IoT or other markets.
      - qwertyuiop924 10y ago
        While it might (I don't know) be possible to make the manufacturing process smaller, you couldn't increase the address space without effectively rewriting the entire ISA. You could use bank switching or an MMU to increase the effective address space (allowing the machine to access more RAM than it can physically address), which was done even back in the day, on pretty much every machine. >you'd be able to compete very well on price for the IoT or other markets. Why do you think that the Z80 and the 6502 (and their derivatives) are still on the market? :-D
Marazan 10y ago
If a 1 MHz 6502 could match a 4MHz Z80 then that would mean a C64 could match a ZX Spectrum (which was clocked at 3.5 MHz) for performance in not sprite blitting scenarios. Which it couldn't. The spectrum smashed the C64 for speed of numerical operations, that's why the specrrum had lots of wireframe and solid filled 3d games and the C64 didn't. Like, Carrier Command on the Spectrum vs the abomination that appeared under the Carrier Command logo that appeared on the Commodore.
- Graham24 10y ago
  It's been 30 years man, let it go.
  - Marazan 10y ago
    Never!
- rasz_pl 10y ago
  sure http://www.hardcoregaming101.net/freescape/freescape.htm http://www.hardcoregaming101.net/freescape/freescape.htm nothing like a rose tinted glasses and fanboizm when it comes to membering those fluid 60fps full color FPS Spectrum games.
  - Marazan 10y ago
    Sorry, what were you saying? I fell asleep waiting for the C64 version of Total Eclipse to render a new frame