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Silicon Motion graphics chip SM750

Posted: Tue Apr 27, 2021 2:59 am
by kelli217

Get one of these and put it on an expansion card... ?

I saw it on Jeff Geerling.

It's a GPU designed for use in embedded systems, supports HD resolution.


Silicon Motion graphics chip SM750

Posted: Tue Apr 27, 2021 4:50 am
by TomXP411

Not likely. This is a PCI Express device; no way will it interface with an 8-bit 6502 bus without additional, complex hardware... by the time you're done, you may as well have just stuck a Raspberry Pi in there, instead.

 


Silicon Motion graphics chip SM750

Posted: Tue Apr 27, 2021 3:55 pm
by BruceMcF

Quite ... "designed for embedded systems" needs parsing to find out what kind of embedded system it is referring to. Nowadays the "embedded" system might be built around a 64bit x86 processor.

Indeed, a RPi would be easier to interface ... there's plenty of GPIO for an eight bit data port, five address lines for a pseudo register system, the R/W line, and a toggle bit for a circuit that holds the RDY line once the RPi is selected until the release bit is toggled. Other than the RDY hold circuit it would mostly be 3.3V/5V level shifters.


Silicon Motion graphics chip SM750

Posted: Tue Apr 27, 2021 6:23 pm
by kelli217

It does have an I²C interface, though. ? 


Silicon Motion graphics chip SM750

Posted: Wed Apr 28, 2021 2:39 am
by BruceMcF


8 hours ago, kelli217 said:




It does have an I²C interface, though. ? 



Yes, I'd like to look at a datasheet to see whether that is a port for access by the controller or an I/O port for the controller to use. It seems like it could be the latter, since it also lists "GPIO", which would be a bit confusing as a way to describe an access port but could be a handy addition for the controller to use.


Silicon Motion graphics chip SM750

Posted: Tue May 04, 2021 1:57 am
by Falken

The oldest graphics chip that is still manufactured is the Matrox G200 according to my knowledge. But I guess even that one is already too advanced.


Silicon Motion graphics chip SM750

Posted: Tue May 04, 2021 4:54 pm
by TomXP411


14 hours ago, Falken said:




The oldest graphics chip that is still manufactured is the Matrox G200 according to my knowledge. But I guess even that one is already too advanced.



"Advanced" may be the wrong word, but the G200 is an AGP card, and that's designed to be coupled with an era-appropriate CPU that has an AGP bus. I can't imagine making that work with a 6502 without custom silicon.

For that matter, no true VGA chipset is going to work with a 6502. The bus interface and BIOS requirements alone are going to make VGA chipsets incompatible.

At best, you might make an 8-bit ISA VGA chip work, but you'd still have to write a custom BIOS and translate between the 6502 and the ISA bus... and the irony there is that the 6502 at 8MHz is about 3 times faster than the ISA bus at 8 Mhz, so you'd actually have to slow the CPU down to work with an ISA video card.