Here is one crazy post. My question is it possible or has anyone tempted to make a Desktop processor using an arduino? I'm don't mean a 6508 processor in the Z80 computer. I have saw that before. I was just wondering if it is possible or someone tried already. It got me curious about how arduino and it's processors came from the 8bit to 32bit. Also I don't mean to be a full functional Desktop processor. Just getting the basic up and running maybe even getting into the Bios or something, things like that.
This is not a project for me. I Just got me curious about what is possible or not and if anyone in the arduino community has tried.
@bobcousins I have tired this on the past. It is great. But I was more curious if anyone took a more modern motherboard and slap an arduino micro processor on it to get it to come alive.
Putting aside the various interfaces that you would have to mimic in order to get the motherboard chipset to play ball, there's the simple issue of pin count. According to Wikipedia, an AMD AM4 CPU socket, for example, has 1,331 pins.
An ATMEGA2560, for example, has just 100 pins - not all of which are I/O port pins.
Other CPUs have varying pin counts as shown in this Wikipedia table where it's pretty clear that the pin count is in the 1000+ for modern CPUs.
The basics have nothing to do with a BIOS. I can only speak of the INTEL 386/486 series and from memory going back to 1990 something.
The "processor" Has three logical processors all coordinated. The first is the usual memory/register processing just like most Arduinos. Then there is the IO processor which has access to the same memory plus 1024 i/o address to connect to peripheral devices to read and write. This processor may also control DMA processing.
Finally there is the interrupt processor which controls by priority the main processor and can interrupt a current interrupt code with one with higher priority.
My programming only related to serial data communications and took many months to just get that working without error.
So, I do not think anyone would actually dedicate their lifetime to creating an emulation of a processor like you mention.
Hey @Paul_KD7HB you are right. Someone would not spend a lifetime making something like this work. I honestly don’t want to either. It was a big question on my mind for over 10 years. Back then cpus and motherboards was much more simple. Well they wasn’t it’s much more then that. I just mean you can do things back 10 to 15 years ago that it would be hard to do with a modern processor today.
In the days of 6502 and Z80, it was doable for an amateur or couple of guys in a garage to create a "PC" in a reasonable timescale (what might be called a single board computer) with the CPU, RAM, VGA chip and a bunch of discrete logic chips.
However when the IBM PC came out in 1979 it moved beyond that, where you would need a team of people and some resources to recreate it. I remember in 1987 we just started to get PCs in the office, but there was one high powered graphic workstation which was dedicated exclusively to PCB layout. Before that point, everything was designed and drawn on paper.
The first IBM PC had a fairly modest CPU, but relied on a bunch of specialized 80XX chips to provide support functions. You can actually find schematics online for IBM PC XT.
Look at what the Chinese heavyweights are now doing in the area of competition with the X86, that is Intel/AMD, and ARM etc. processors which are to be found in most desktop PCs.
They are using risc-v as the basis for their new product developments in this area and investing huge amounts of talent/resources and should soon have some useful results. Incidentally, risc-v processors, albeit with relatively modest performance compared to desktop/server needs, are currently used in some of the ESP32 products.
@bobcousins This is true. And over time CPU, motherboards, memory, hard drives and GPU became bigger and better to where a lot of companies are making theses more available to other developers to make newer and better version of each components.
