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Mega65 is a nostalgia project aimed at targeting a specific kind of older computer system. If practical and simple were the goals, it wouldn't be using an 8-bi

by hajile 2y ago

Mega65 is a nostalgia project aimed at targeting a specific kind of older computer system. If practical and simple were the goals, it wouldn't be using an 8-bit chip nor would it be focused on things like BASIC as these kinds of things make things harder rather than easier. Mega65 is about working within constraints, but (to me), the bend of the complexity curve where things are simple enough to understand, but powerful enough to do necessary tasks requires much larger software and hardware resources than what a system like Mega65 offers. At a bare minimum, I believe you'd want a much more powerful single-core machine with the ability to do floating point and vector calculations while having access to at least a couple hundred megabytes of RAM and a few gigabytes of storage. Something more along the lines of a Pi Zero, but based on open hardware and open chip designs seems to be around the point where it is powerful enough to do all the common, non-connected tasks a user might need to do while still being simple enough that you could understand most of the moving parts if you wanted to take the time.

tines 2y ago
I agree completely. I've looked at designing a system around the Pi Zero, but it's so much work for someone with the time and skills that I (don't) have. And the Pi Zero doesn't seem to have the kind of I/O capability that I'm looking for.
- thijson 2y ago
  I feel like the RP2040 or RP2350 approach the simplicity of these older machines. https://www.raspberrypi.com/products/rp2350/ https://www.raspberrypi.com/products/rp2350/ The documentation is pretty good. Reading it reminds me of going through the documentation provided with my Tandy Color Computer as a kid.
  - 082349872349872 2y ago
    I appreciate that when BCPL got its first floating point support, almost half a century after initial release, it was only because Martin Richards was writing a flight simulator for his Pi.
nine_k 2y ago
Actually, something comparable to the original Symbolics Lisp Machines could be at the sweet spot where you still understand the whole system from the hardware up, but have powerful enough tools to be actually productive.
Mr_Minderbinder 2y ago
>If practical and simple were the goals, it wouldn't be using an 8-bit chip nor would it be focused on things like BASIC as these kinds of things make things harder rather than easier. A 32-bit word size is the absolute minimum that I would consider “practical”. With that you can comfortably implement reasonable floating point and integer arithmetic that can solve most of the common practical problems you encounter in science, business or engineering. Still people criticised the System/360 because it was 32-bit, saying it wasn’t enough compared to the 36-bit word size computers that preceded it. Mechanical calculators generally had ten decimal digits of precision so the thinking was that digital computers needed to at least match or exceed that.
- kbolino 2y ago
  Plenty of older microcomputers got by just fine with only 8 bits in a word. That's enough room to fit two binary-coded decimal digits and thus perform all the common arithmetic operations one or two digits at a time. Many quite good handheld calculators and early personal computers were able to handle practical computations very well in this way, albeit at speeds far below the billions of operations per second expected of modern computers. The advantage of 32-bit word size is more for interoperability with modern systems and familiarity to modern programmers and programming languages.
  - Mr_Minderbinder 2y ago
    No one in their right mind would design a general purpose computer system from scratch with an 8-bit word size unless they were forced to. Neither Zuse nor Eckert and Mauchly ever did. > Plenty of older microcomputers got by just fine with only 8 bits in a word. They got by fine on your kid’s desk. Those processors were better suited for implementing smart terminals that people would use to interface with the computer that would actually solve your problem. > That's enough room to fit two binary-coded decimal digits and thus perform all the common arithmetic operations one or two digits at a time. Why perform them one digit at a time when you can perform them 10 digits at a time? Why force your users to adopt a programming model where you have to implement arbitrary precision arithmetic anytime you want to use a number larger than 255? Or have to implement a useful floating point in software? Or be forced to pull in libraries or use some environment were that stuff is pre-implemented in order to do basic operations that previously could be done in a single line in assembly? >...albeit at speeds far below the billions of operations per second expected of modern computers. They performed at speeds below what was expected of computers from the 50s and 60s. > The advantage of 32-bit word size is more for interoperability with modern systems and familiarity to modern programmers and programming languages. No it is not about modern computing or modern programmers. 32-bit or similar word sizes were the standard for electronic computing since the earliest times because there are intrinsic advantages. Nobody did 8-bit computing before micro-processors from the 70s because it would have been stupid to limit yourself that way if you didn’t need to.

by hajile 2y ago

tines 2y ago

I agree completely. I've looked at designing a system around the Pi Zero, but it's so much work for someone with the time and skills that I (don't) have. And the Pi Zero doesn't seem to have the kind of I/O capability that I'm looking for.

thijson 2y ago
I feel like the RP2040 or RP2350 approach the simplicity of these older machines. https://www.raspberrypi.com/products/rp2350/ https://www.raspberrypi.com/products/rp2350/ The documentation is pretty good. Reading it reminds me of going through the documentation provided with my Tandy Color Computer as a kid.
- 082349872349872 2y ago
  I appreciate that when BCPL got its first floating point support, almost half a century after initial release, it was only because Martin Richards was writing a flight simulator for his Pi.

nine_k 2y ago

Actually, something comparable to the original Symbolics Lisp Machines could be at the sweet spot where you still understand the whole system from the hardware up, but have powerful enough tools to be actually productive.

Mr_Minderbinder 2y ago

>If practical and simple were the goals, it wouldn't be using an 8-bit chip nor would it be focused on things like BASIC as these kinds of things make things harder rather than easier. A 32-bit word size is the absolute minimum that I would consider “practical”. With that you can comfortably implement reasonable floating point and integer arithmetic that can solve most of the common practical problems you encounter in science, business or engineering. Still people criticised the System/360 because it was 32-bit, saying it wasn’t enough compared to the 36-bit word size computers that preceded it. Mechanical calculators generally had ten decimal digits of precision so the thinking was that digital computers needed to at least match or exceed that.

kbolino 2y ago
Plenty of older microcomputers got by just fine with only 8 bits in a word. That's enough room to fit two binary-coded decimal digits and thus perform all the common arithmetic operations one or two digits at a time. Many quite good handheld calculators and early personal computers were able to handle practical computations very well in this way, albeit at speeds far below the billions of operations per second expected of modern computers. The advantage of 32-bit word size is more for interoperability with modern systems and familiarity to modern programmers and programming languages.
- Mr_Minderbinder 2y ago
  No one in their right mind would design a general purpose computer system from scratch with an 8-bit word size unless they were forced to. Neither Zuse nor Eckert and Mauchly ever did. > Plenty of older microcomputers got by just fine with only 8 bits in a word. They got by fine on your kid’s desk. Those processors were better suited for implementing smart terminals that people would use to interface with the computer that would actually solve your problem. > That's enough room to fit two binary-coded decimal digits and thus perform all the common arithmetic operations one or two digits at a time. Why perform them one digit at a time when you can perform them 10 digits at a time? Why force your users to adopt a programming model where you have to implement arbitrary precision arithmetic anytime you want to use a number larger than 255? Or have to implement a useful floating point in software? Or be forced to pull in libraries or use some environment were that stuff is pre-implemented in order to do basic operations that previously could be done in a single line in assembly? >...albeit at speeds far below the billions of operations per second expected of modern computers. They performed at speeds below what was expected of computers from the 50s and 60s. > The advantage of 32-bit word size is more for interoperability with modern systems and familiarity to modern programmers and programming languages. No it is not about modern computing or modern programmers. 32-bit or similar word sizes were the standard for electronic computing since the earliest times because there are intrinsic advantages. Nobody did 8-bit computing before micro-processors from the 70s because it would have been stupid to limit yourself that way if you didn’t need to.