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> Tramiel never understood or invested in growing a platform or growing, expanding, intercompatible product line. Each Commodore machine under his watch was a b

> Tramiel never understood or invested in growing a platform or growing, expanding, intercompatible product line. Each Commodore machine under his watch was a brand new machine, not compatible with the others except for maybe a few peripherals. But, iirc, very very very few computer manufacturers prioritized compatibility in that way in those days though, and for good reason, it would have be stupid expensive. Some manufacturers got around the problem (Commodore did this as a matter of fact) by incorporating all or part of the previous line in the new machines and enabling compatibility modes.

cmrdporcupine 5y ago
Well, that's simply not true for the Atari 8-bit line (mostly compatible from 1979 right through to the XE series which continued right into the late 80s and even early 90s), the Apple II line (II, II+, IIe, IIc, IIgs, as well as cards that slotted into Macs), MSX and MSXII, and of course the 16-bit era with MS-DOS machines and Macintosh, Amiga and Atari ST lines. Honestly, Commodore and Sinclair 8-bits are the outliers here? C-128 came quite late in the game.
- sillyquiet 5y ago
  ok, I stand corrected, but I will say that the Apple II line represented smaller iterations of the generally same architecture, right? i.e., Commodore I guess didn't iterate within the same architecture as much, breaking that compatibility more easily.
  - timbit42 5y ago
    There was a fair bit of compatibility within the PET/CBM line. Outside of that, every system had an incompatible memory map.
  - rbanffy 5y ago
    One of the key difficulties of making a faster Apple II was the time-critical routines involved in reading/writing floppies. It was not sufficient to throttle back to 1 MHz when running time-critical loops, but one would need to emulate the timing of a 6502 doing that. Commodore made a better 6502 for the C65, but it'd wouldn't work on an Apple II because it wouldn't have the same cycle timings. The IIgs and the //c+ was faster and very compatible thanks to a crazy number of hacks in them to acommodate Woz's brilliance. In retrospect, Apple should have released a Disk II+ that isolated the timings from the CPU and let software break. Commodore should probably have done the same.
- timbit42 5y ago
  Commodore did have a fair bit of compatibility within the PET/CBM line. The C128 is a good example of how Commodore did compatibility wrong. Instead of creating a 100% C64 compatible mode, separate from the C128 mode, they should have taken the C64 and added a second bank of 64K of RAM, an MMU, an enhanced VIC-III with added registers for the enhanced graphics (eg. colors, resolutions, sprites), a second SID, a 2 MHz CPU, an enhanced KERNAL, and an enhanced BASIC that had the same tokens as BASIC v2. While C128 mode was very similar to the C64 mode, it wasn't enough to run hardly any C64 apps and games without modifications. I don't blame Bil Herd for what the C128 is though. It is a great computer, especially considering he was fighting the top levels of Commodore to get it out the door. If he'd had more support, it could have been better.
  - cmrdporcupine 5y ago
    I feel like the right way to do it would have been to have shipped a C64 compatibility mode in the Amiga, instead. An A500+ with a 100% C64 compatible mode capable of running a C64 in a window even, IMHO would have been great product that could have sold like gangbusters because the C64 was still a hot selling product right through the late 80s. I can't imagine it would have been that expensive to do given how well understood the C64 architecture was at that point. Either that or have built the Amiga around a 65816 or similar instead of 68000. Like the IIgs but with even better sound and graphics.
    - rbanffy 5y ago
      > Either that or have built the Amiga around a 65816 or similar instead of 68000. This would be a huge mistake. The 68000 was much more elegant and had a way forward, something the 65816 never had. Had they gone the 65816 route, there would never be an Amiga with a better CPU except, maybe, a faster one. And the whole Amiga 1000/2000/500/600 was saddled with TV signal timing dependencies that made it more difficult to have better graphics and ended up having to play catch-up with VGA and Sound Blaster.
      - rasz 5y ago
        65816 at 7MHz would be faster than 68000 despite 8 bit databus. one modified for full 16bit would fly circles around motorola. Bill Mensch would have no problem extending and growing this chip as long as Commodore was buying. 65816 already has reserved mnemonic for expanding instruction set further.
timbit42 5y ago
> But, iirc, very very very few computer manufacturers prioritized compatibility in that way in those days though, and for good reason, it would have be stupid expensive. You don't recall correctly. The only major brand that didn't prioritize compatibility was Commodore. Maintaining compatibility limited the ability to add new features but it wasn't 'stupid expensive'. What is expensive is throwing out what you have and creating something incompatible from scratch. When you have hundreds of thousands or millions of units out there, not being backward compatible means you risk losing most of those customers. Nearly everything that ran on the original Apple II ran on the IIe and IIgs, and nearly everything that ran on the Atari 800 ran on the XL and XE models. Nearly everything that ran on the original 1981 IBM PC can run on a modern PC compatible.
- sillyquiet 5y ago
  Fair enough, I stand corrected, but I guess I meant maintaining compatibility when you change architectures is stupid expensive.
  - timbit42 5y ago
    With that take, "very, very, very few" means none. Who did that?
    - sillyquiet 5y ago
      Commodore, later on, when they put a whole c64 in the c128, but I take your meaning.
      - rasz 5y ago
        c128 was a case of idle engineers with no plan/strategy gluing unsold garbage components (graphic chip left over from earlier failed project and Z80) to c64 and scamming public with misleading name. 2 CPUs, 2 graphic chips, 2 monitor outputs, all in one package.
        5y ago

cmrdporcupine 5y ago

Well, that's simply not true for the Atari 8-bit line (mostly compatible from 1979 right through to the XE series which continued right into the late 80s and even early 90s), the Apple II line (II, II+, IIe, IIc, IIgs, as well as cards that slotted into Macs), MSX and MSXII, and of course the 16-bit era with MS-DOS machines and Macintosh, Amiga and Atari ST lines. Honestly, Commodore and Sinclair 8-bits are the outliers here? C-128 came quite late in the game.

sillyquiet 5y ago
ok, I stand corrected, but I will say that the Apple II line represented smaller iterations of the generally same architecture, right? i.e., Commodore I guess didn't iterate within the same architecture as much, breaking that compatibility more easily.
- timbit42 5y ago
  There was a fair bit of compatibility within the PET/CBM line. Outside of that, every system had an incompatible memory map.
- rbanffy 5y ago
  One of the key difficulties of making a faster Apple II was the time-critical routines involved in reading/writing floppies. It was not sufficient to throttle back to 1 MHz when running time-critical loops, but one would need to emulate the timing of a 6502 doing that. Commodore made a better 6502 for the C65, but it'd wouldn't work on an Apple II because it wouldn't have the same cycle timings. The IIgs and the //c+ was faster and very compatible thanks to a crazy number of hacks in them to acommodate Woz's brilliance. In retrospect, Apple should have released a Disk II+ that isolated the timings from the CPU and let software break. Commodore should probably have done the same.
timbit42 5y ago
Commodore did have a fair bit of compatibility within the PET/CBM line. The C128 is a good example of how Commodore did compatibility wrong. Instead of creating a 100% C64 compatible mode, separate from the C128 mode, they should have taken the C64 and added a second bank of 64K of RAM, an MMU, an enhanced VIC-III with added registers for the enhanced graphics (eg. colors, resolutions, sprites), a second SID, a 2 MHz CPU, an enhanced KERNAL, and an enhanced BASIC that had the same tokens as BASIC v2. While C128 mode was very similar to the C64 mode, it wasn't enough to run hardly any C64 apps and games without modifications. I don't blame Bil Herd for what the C128 is though. It is a great computer, especially considering he was fighting the top levels of Commodore to get it out the door. If he'd had more support, it could have been better.
- cmrdporcupine 5y ago
  I feel like the right way to do it would have been to have shipped a C64 compatibility mode in the Amiga, instead. An A500+ with a 100% C64 compatible mode capable of running a C64 in a window even, IMHO would have been great product that could have sold like gangbusters because the C64 was still a hot selling product right through the late 80s. I can't imagine it would have been that expensive to do given how well understood the C64 architecture was at that point. Either that or have built the Amiga around a 65816 or similar instead of 68000. Like the IIgs but with even better sound and graphics.
  - rbanffy 5y ago
    > Either that or have built the Amiga around a 65816 or similar instead of 68000. This would be a huge mistake. The 68000 was much more elegant and had a way forward, something the 65816 never had. Had they gone the 65816 route, there would never be an Amiga with a better CPU except, maybe, a faster one. And the whole Amiga 1000/2000/500/600 was saddled with TV signal timing dependencies that made it more difficult to have better graphics and ended up having to play catch-up with VGA and Sound Blaster.
    - rasz 5y ago
      65816 at 7MHz would be faster than 68000 despite 8 bit databus. one modified for full 16bit would fly circles around motorola. Bill Mensch would have no problem extending and growing this chip as long as Commodore was buying. 65816 already has reserved mnemonic for expanding instruction set further.

timbit42 5y ago

> But, iirc, very very very few computer manufacturers prioritized compatibility in that way in those days though, and for good reason, it would have be stupid expensive. You don't recall correctly. The only major brand that didn't prioritize compatibility was Commodore. Maintaining compatibility limited the ability to add new features but it wasn't 'stupid expensive'. What is expensive is throwing out what you have and creating something incompatible from scratch. When you have hundreds of thousands or millions of units out there, not being backward compatible means you risk losing most of those customers. Nearly everything that ran on the original Apple II ran on the IIe and IIgs, and nearly everything that ran on the Atari 800 ran on the XL and XE models. Nearly everything that ran on the original 1981 IBM PC can run on a modern PC compatible.

sillyquiet 5y ago
Fair enough, I stand corrected, but I guess I meant maintaining compatibility when you change architectures is stupid expensive.
- timbit42 5y ago
  With that take, "very, very, very few" means none. Who did that?
  - sillyquiet 5y ago
    Commodore, later on, when they put a whole c64 in the c128, but I take your meaning.
    - rasz 5y ago
      c128 was a case of idle engineers with no plan/strategy gluing unsold garbage components (graphic chip left over from earlier failed project and Z80) to c64 and scamming public with misleading name. 2 CPUs, 2 graphic chips, 2 monitor outputs, all in one package.
      - 5y ago