Thanks for the input. I have only really done much software before too so this is a big jump for me.
Those numbers (8042 - keyboard + extra bits 8253/8254 - Timer 8259 - Interrupt controller 8237 - Possibly you might need DMA controller if you want to use floppy etc) are the identification numbers of the chips themselves right?
Cheers, Rex
On Fri, 2012-11-23 at 10:57 +0100, Rudolf Marek wrote:
How hard would it be to design, source components and construct a motherboard for something simple such as a 486DX from scratch?
I'm the software guy but, I think you don't need the chipset, maybe 80386SX with static ram aka 62512 and some simple decoders would be good choice. For dynamic RAM you would need some controller. For the "legacy" PC i think you need to implement
8042 - keyboard + extra bits 8253/8254 - Timer 8259 - Interrupt controller 8237 - Possibly you might need DMA controller if you want to use floppy etc
Maybe doing this in some CPLD/FPGA would also be an option.
For the bus, I would choose ISA...
80386SX has 16bit bus so not so many wires. Sufficiently low clocks.
Thanks Rudolf