At Software Arts I wrote or worked on the IL interpreter for the TRS 80 Model III, the DEC Rainbow, the Vector Graphic, the beginnings of the Apple Lisa port, as well as the IBM PC port. To put you into the state of mind at the time,
- in the pre-PC era, the microcomputer ecosystem was extremely fragmented in terms of architectures, CPUs, and OS's. 6502, z80, 68K, z8000, 8088. DOS, CPM, CPM/86, etc. Our publisher (Personal Software) wanted as much breadth of coverage, as you might imagine
- one strong positive benefit of porting from 6502 assembly to IL and using an interpreter was that it enabled the core code to remain the same while leaving the complex work of paging and/or memory mapping to the interpreter, enabling access to 'extended memory' without touching or needing to re-test the core VisiCalc code. Same goes for display architectures, printer support, file system I/O, etc.
- another strong benefit was the fact that, as the author alludes to, the company was trying to transition to being more than a one hit wonder by creating a symbolic equation solver app - TK!Solver - that shared the interpreter.
Of course, the unavoidable result is that the interpreter - without modern affordances such as JIT compilation - was far less snappy than native code. We optimized the hell out of it and it wasn't unusable, but it did feel laggy.
Fast forward to when I left SoftArts and went across the street to work for my friend Jon Sachs who had just co-founded Lotus with Mitch Kapor. Mitch & Jon bet 100% that the PC would reset the ecosystem, and that the diversity of microcomputers would vanish.
Jon single-handedly wrote 1-2-3 in hand-tuned assembly language. Yes, 1-2-3 was all about creating a killer app out of 1.spreadsheet+2.graphics+3.database. That was all Mitch.
But, equally, a killer aspect of 1-2-3 was SPEED. It was mind-blowing. And this was all Jon. Jon's philosophy was that there is no 'killer feature' that was more important than speed.
When things are moving fast and the industry is taking shape, you make the best decisions you can given hunches about the opportunities you spot, and the lay of the technical and market landscape at that moment. You need to make many key technical and business decisions in almost an instant, and in many ways that determines your fate.
Even in retrospect, I think the IL port was the right decision by Dan & Bob given the microcomputing ecosystem at the time. But obviously Mitch & Jon also made the right decision for their own time - just a matter of months later. All of them changed the world.
- in the pre-PC era, the microcomputer ecosystem was extremely fragmented in terms of architectures, CPUs, and OS's. 6502, z80, 68K, z8000, 8088. DOS, CPM, CPM/86, etc. Our publisher (Personal Software) wanted as much breadth of coverage, as you might imagine
- one strong positive benefit of porting from 6502 assembly to IL and using an interpreter was that it enabled the core code to remain the same while leaving the complex work of paging and/or memory mapping to the interpreter, enabling access to 'extended memory' without touching or needing to re-test the core VisiCalc code. Same goes for display architectures, printer support, file system I/O, etc.
- another strong benefit was the fact that, as the author alludes to, the company was trying to transition to being more than a one hit wonder by creating a symbolic equation solver app - TK!Solver - that shared the interpreter.
Of course, the unavoidable result is that the interpreter - without modern affordances such as JIT compilation - was far less snappy than native code. We optimized the hell out of it and it wasn't unusable, but it did feel laggy.
Fast forward to when I left SoftArts and went across the street to work for my friend Jon Sachs who had just co-founded Lotus with Mitch Kapor. Mitch & Jon bet 100% that the PC would reset the ecosystem, and that the diversity of microcomputers would vanish.
Jon single-handedly wrote 1-2-3 in hand-tuned assembly language. Yes, 1-2-3 was all about creating a killer app out of 1.spreadsheet+2.graphics+3.database. That was all Mitch. But, equally, a killer aspect of 1-2-3 was SPEED. It was mind-blowing. And this was all Jon. Jon's philosophy was that there is no 'killer feature' that was more important than speed.
When things are moving fast and the industry is taking shape, you make the best decisions you can given hunches about the opportunities you spot, and the lay of the technical and market landscape at that moment. You need to make many key technical and business decisions in almost an instant, and in many ways that determines your fate.
Even in retrospect, I think the IL port was the right decision by Dan & Bob given the microcomputing ecosystem at the time. But obviously Mitch & Jon also made the right decision for their own time - just a matter of months later. All of them changed the world.