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The first version of Microsoft BASIC was written for the MITS Altair 8800 – which didn't come with any graphics hardware, it was normally used over a serial por

The first version of Microsoft BASIC was written for the MITS Altair 8800 – which didn't come with any graphics hardware, it was normally used over a serial port, from a teletype. Given a serial port talking to a teletype, full-screen editing is impossible. Microsoft went on to port their BASIC to more platforms, many of which were capable of full-screen editing, yet they kept with the line-oriented interface–why? It was a lowest common denominator which worked across all hardware and was trivial to bring up on a new hardware platform or operating system–full screen editing would have required a lot more platform-specific code to be written, and would have been more affected by differences in capabilities between different platforms (screen sizes/etc).

scarface74 4y ago
Microsoft didn’t “port” their software in the traditional sense. It was a clean rewrite for each platform. For instance, the Apple // graphics memory layout was really weird.
- timbit42 4y ago
  It was not a clean rewrite for each platform. It wasn't even a clean rewrite for each processor. Forensic analysis proves this. For example, the MICROSOFT! Easter egg from the 6502 version of Microsoft BASIC remained in the 6809 version even though there is no longer code to display it. Source: https://www.pagetable.com/?p=43 https://www.pagetable.com/?p=43
  - deleted 4y ago
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- skissane 4y ago
  > Microsoft didn’t “port” their software in the traditional sense. It was a clean rewrite for each platform. Not true. See https://devblogs.microsoft.com/commandline/microsoft-open-sources-gw-basic/ https://devblogs.microsoft.com/commandline/microsoft-open-so... in particular: > This source was ‘translated’? > Each of the assembly source files contains a header stating This translation created 10-Feb-83 by Version 4.3 > Since the Instruction Set Architecture (ISA) of the early processors used in home and personal computers weren’t spectacularly different from one another, Microsoft was able to generate a substantial amount of the code for a port from the sources of a master implementation. (Alas, sorry, we’re unable to open-source the ISA translator.) You also write: > For instance, the Apple // graphics memory layout was really weird. That’s largely irrelevant because the core of Microsoft BASIC was text-only and had no graphics support. Graphics support was an extension, which was highly platform-specific, since platforms varied greatly in terms of their graphical capabilities and how those capabilities were implemented
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miohtama 4y ago
Full screen editing also requires much more RAM. Late 70s and early 80s computers might have had 4 KB - 32 KB RAM. With such limited system, it is hard to host a full screen editor or any advanced compiler with jump labels.

scarface74 4y ago

Microsoft didn’t “port” their software in the traditional sense. It was a clean rewrite for each platform. For instance, the Apple // graphics memory layout was really weird.

timbit42 4y ago
It was not a clean rewrite for each platform. It wasn't even a clean rewrite for each processor. Forensic analysis proves this. For example, the MICROSOFT! Easter egg from the 6502 version of Microsoft BASIC remained in the 6809 version even though there is no longer code to display it. Source: https://www.pagetable.com/?p=43 https://www.pagetable.com/?p=43
- deleted 4y ago
  [deleted]
skissane 4y ago
> Microsoft didn’t “port” their software in the traditional sense. It was a clean rewrite for each platform. Not true. See https://devblogs.microsoft.com/commandline/microsoft-open-sources-gw-basic/ https://devblogs.microsoft.com/commandline/microsoft-open-so... in particular: > This source was ‘translated’? > Each of the assembly source files contains a header stating This translation created 10-Feb-83 by Version 4.3 > Since the Instruction Set Architecture (ISA) of the early processors used in home and personal computers weren’t spectacularly different from one another, Microsoft was able to generate a substantial amount of the code for a port from the sources of a master implementation. (Alas, sorry, we’re unable to open-source the ISA translator.) You also write: > For instance, the Apple // graphics memory layout was really weird. That’s largely irrelevant because the core of Microsoft BASIC was text-only and had no graphics support. Graphics support was an extension, which was highly platform-specific, since platforms varied greatly in terms of their graphical capabilities and how those capabilities were implemented
- deleted 4y ago
  [deleted]

miohtama 4y ago

Full screen editing also requires much more RAM. Late 70s and early 80s computers might have had 4 KB - 32 KB RAM. With such limited system, it is hard to host a full screen editor or any advanced compiler with jump labels.