6 ms·

Why wasn’t this chip more common in arcade and game consoles vs. 6502 and Z80? Cost?

by trzy 3y ago

daltont 3y ago
Williams Electronics used the 6809 in Defender, Robotron, Joust and Sinistar. It was more expensive. Tandy chose it for the TRS-80 Color Computer and sacrificed dedicated sound generation hardware for it to keep costs down.
- koz1000 3y ago
  It also ran Williams' line of pinball machines all the way until 1999.
  - csixty4 3y ago
    Same year I faxed them a resume touting my 8-bit assembly experience. Dodged a bullet there, although I'm sure I could have picked up another architecture pretty quickly.
    - koz1000 3y ago
      We switched to C++. Nobody had a problem with the switch, although multitheading became a sticky point with some of the developers so we had to write an API to simulate nonpreemptive tasking like the old assembly system.
- kjs3 3y ago
  The 6809 is not the same things as the 6800. Related, but quite different.
- cmrdporcupine 3y ago
  Although the 6809 was assembly-source level compatible with most of the 6800 opcodes, it was not binary compatible, and was in fact a totally new (better) design.
- jacquesm 3y ago
  > Tandy chose it for the TRS-80 Color Computer and sacrificed dedicated sound generation hardware for it to keep costs down. The result of that though is an excellent example of 'software eating the world' and allowed for a whole pile of other tricks to be pulled (in software!) that would have required more circuitry in other computers. For instance, the tape interface used it, as well as the joystick interface. If you were a bit more adventurous you could use it for analog in as well as analog out.
duskwuff 3y ago
Primarily cost. In 1975, the 6800 cost $175 (which was already a dramatic reduction from the initial price of $360); the 6502 launched that year at $25. Motorola dropped prices on the 6800 in response, but they still couldn't match MOS's pricing.
- systems_glitch 3y ago
  Indeed, the mask correction process that MOS came up with was really their killer advancement w.r.t. keeping design cost down, even considering the dramatically simpler 6502 core.
- jasonwatkinspdx 3y ago
  Just to save anyone else the effort, inflation adjusted those numbers are: $1,031.36, $2,121.66, and $442.01.
  - jordemort 3y ago
    Based on what? The data sources I can find put inflation since 1975 at ~470%, which sounds high, but even then $25 is only ~$140, not $442.01
    - jasonwatkinspdx 3y ago
      I used this: https://www.bls.gov/data/inflation_calculator.htm https://www.bls.gov/data/inflation_calculator.htm Checking again it looks like I'd used this calculator in the past for $250 so I got an extra zero in there by accident via autocomplete, sorry. I can no longer edit the original.
angiosperm 3y ago
The 6502 was a better chip (designed with hindsight on the 6800), and also cheaper. Z80 could run 8080 code.
- kjs3 3y ago
  Just because it came second, doesn't mean it's better. It was cheaper, and you can see where they cut corners to be cheaper. For me, if nothing else, the 16-bit stack and index registers in the 6800 make it hands down a better chip to program. But the 6502 was cheaper, sure, and some people probably like to spend all day thinking about what stuff to cram into the first 256 bytes to be performant.
  - systems_glitch 3y ago
    If I had to pick one over the other to write serious software in forever, it'd definitely be the 6800. Remember, you can also spend all day exploiting zero page mode in the 6800, but you'll never be able to move the 6502's stack :P
  - angiosperm 3y ago
    The "zero-page", the low 256 bytes, amounted to a big register bank; compilers for 6502 used it that way. The hardware stack was for return addresses only, and was plenty; a zero-page pair pointed to the stack for arguments and locals. The designer of the ARM noted that her programs ran faster on 6502 than when ported to early 8086, largely because the latter was relatively so inefficient.
    - kjs3 3y ago
      6502 fanbois like to pretended the zero page was registers because they had no choice and every since have tried to convince people that a weakness is a virtue. Better architectures don't have to pretend. And no one was talking about the 8086; most people who try to drag in an irrelevant processor to 'prove' 6502 superiority go 'but Z80!', so cudos for some originality. But it is now as it has always been: when you call someones pet processor ugly, you'll get all the specious arguments you can stomach.
dboreham 3y ago
The Z80 was a generation later, so its appropriate comparison is the 6809, used in the Dragon and Tandy Color Computer.
- djmips 3y ago
  It's not so clear. Z80 is two years after the 6800 but the 6809 is two years after the Z80. 1974 - 6800 / 8080 1975 - 6502 1976 - Z80 1977 - 8085 1978 - 6809 / 8086 1979 - 68000 / 8088 / Z8000

Why wasn’t this chip more common in arcade and game consoles vs. 6502 and Z80? Cost?

by trzy 3y ago

Why wasn’t this chip more common in arcade and game consoles vs. 6502 and Z80? Cost?

Williams Electronics used the 6809 in Defender, Robotron, Joust and Sinistar. It was more expensive. Tandy chose it for the TRS-80 Color Computer and sacrificed dedicated sound generation hardware for it to keep costs down.

koz1000 3y ago
It also ran Williams' line of pinball machines all the way until 1999.
- csixty4 3y ago
  Same year I faxed them a resume touting my 8-bit assembly experience. Dodged a bullet there, although I'm sure I could have picked up another architecture pretty quickly.
  - koz1000 3y ago
    We switched to C++. Nobody had a problem with the switch, although multitheading became a sticky point with some of the developers so we had to write an API to simulate nonpreemptive tasking like the old assembly system.
kjs3 3y ago
The 6809 is not the same things as the 6800. Related, but quite different.
cmrdporcupine 3y ago
Although the 6809 was assembly-source level compatible with most of the 6800 opcodes, it was not binary compatible, and was in fact a totally new (better) design.
jacquesm 3y ago
> Tandy chose it for the TRS-80 Color Computer and sacrificed dedicated sound generation hardware for it to keep costs down. The result of that though is an excellent example of 'software eating the world' and allowed for a whole pile of other tricks to be pulled (in software!) that would have required more circuitry in other computers. For instance, the tape interface used it, as well as the joystick interface. If you were a bit more adventurous you could use it for analog in as well as analog out.

duskwuff 3y ago

Primarily cost. In 1975, the 6800 cost $175 (which was already a dramatic reduction from the initial price of $360); the 6502 launched that year at $25. Motorola dropped prices on the 6800 in response, but they still couldn't match MOS's pricing.

systems_glitch 3y ago
Indeed, the mask correction process that MOS came up with was really their killer advancement w.r.t. keeping design cost down, even considering the dramatically simpler 6502 core.
jasonwatkinspdx 3y ago
Just to save anyone else the effort, inflation adjusted those numbers are: $1,031.36, $2,121.66, and $442.01.
- jordemort 3y ago
  Based on what? The data sources I can find put inflation since 1975 at ~470%, which sounds high, but even then $25 is only ~$140, not $442.01
  - jasonwatkinspdx 3y ago
    I used this: https://www.bls.gov/data/inflation_calculator.htm https://www.bls.gov/data/inflation_calculator.htm Checking again it looks like I'd used this calculator in the past for $250 so I got an extra zero in there by accident via autocomplete, sorry. I can no longer edit the original.

angiosperm 3y ago

The 6502 was a better chip (designed with hindsight on the 6800), and also cheaper. Z80 could run 8080 code.

kjs3 3y ago
Just because it came second, doesn't mean it's better. It was cheaper, and you can see where they cut corners to be cheaper. For me, if nothing else, the 16-bit stack and index registers in the 6800 make it hands down a better chip to program. But the 6502 was cheaper, sure, and some people probably like to spend all day thinking about what stuff to cram into the first 256 bytes to be performant.
- systems_glitch 3y ago
  If I had to pick one over the other to write serious software in forever, it'd definitely be the 6800. Remember, you can also spend all day exploiting zero page mode in the 6800, but you'll never be able to move the 6502's stack :P
- angiosperm 3y ago
  The "zero-page", the low 256 bytes, amounted to a big register bank; compilers for 6502 used it that way. The hardware stack was for return addresses only, and was plenty; a zero-page pair pointed to the stack for arguments and locals. The designer of the ARM noted that her programs ran faster on 6502 than when ported to early 8086, largely because the latter was relatively so inefficient.
  - kjs3 3y ago
    6502 fanbois like to pretended the zero page was registers because they had no choice and every since have tried to convince people that a weakness is a virtue. Better architectures don't have to pretend. And no one was talking about the 8086; most people who try to drag in an irrelevant processor to 'prove' 6502 superiority go 'but Z80!', so cudos for some originality. But it is now as it has always been: when you call someones pet processor ugly, you'll get all the specious arguments you can stomach.

dboreham 3y ago

The Z80 was a generation later, so its appropriate comparison is the 6809, used in the Dragon and Tandy Color Computer.

djmips 3y ago
It's not so clear. Z80 is two years after the 6800 but the 6809 is two years after the Z80. 1974 - 6800 / 8080 1975 - 6502 1976 - Z80 1977 - 8085 1978 - 6809 / 8086 1979 - 68000 / 8088 / Z8000