[coreboot] 486 Motherboard from scratch
Rex O'Regan
rexoregan20 at yahoo.com.au
Fri Nov 23 13:26:55 CET 2012
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
>
More information about the coreboot
mailing list