GP32 Core

[LauweLoempia]

I don't know if this is the right place to post a suggestion for a new (handheld) console core.. anayway, I am currently on a deep dive into this fantastic MiSTer thing and trying to grasp the whole consequence of FPGA hardware recreation and I posed myself the question: what console system cannot yet be properly emulated (software) but could maybe be possible as a FPGA core? For me the GP32 core came to mind. Yes, it has a small library and was a bit obscure, but it saw a LOT of very nice homebrew games, programs etc. What do you think? Could it be possible? Does anyone care for a GP32 core?

[Vic20-Ian]

I had a GP32 and still have a GP2x and a Pandora.

They are all interesting machines for homebrew and emulation but not very mainstream so will have little interest for many I think.

Why not dig out some documentation on the device and place links in this thread.

p.s. Retitle the thread to GP32

[softtest9]

I had a quick read at Wikipedia about the hardware specs: https://en.wikipedia.org/wiki/GP32#Hardware

About the CPU, it says: "Samsung S3C2400X01 (ARM920T core), 20 (and under) to 133 MHz (overclockable to 166 MHz+ in some cases. Some have even reached 256 MHz (not always stable, low battery life). Overclocking ability is random, however all GP32s are supposed to reach 133 MHz. A few early "bad" units maxed out at 132 MHz.)"

I am not entirely sure how to interpret this, but if the CPU's stock clockspeed is 20 MHz, then it might be somewhat similar to the GBA in terms of performance and complexity, probably slightly more powerful. That would definitely be doable on the MiSTer, but it all depends on whether a developer is interested. Considering how there are only 2 emulators out there, both of them far from finished, I would be surprised if anyone made a core.

[Newsdee]

Didn't the GP32 have a homebrew scene? A core would help preserve some of that.

[ExCyber]

About the CPU, it says: "Samsung S3C2400X01 (ARM920T core), 20 (and under) to 133 MHz (overclockable to 166 MHz+ in some cases. Some have even reached 256 MHz (not always stable, low battery life). Overclocking ability is random, however all GP32s are supposed to reach 133 MHz. A few early "bad" units maxed out at 132 MHz.)"

I am not entirely sure how to interpret this, but if the CPU's stock clockspeed is 20 MHz, then it might be somewhat similar to the GBA in terms of performance and complexity, probably slightly more powerful.

I think it means that a stock GP32 will downclock the CPU as low as 20 MHz when idle to save power, but "full speed" (i.e. not overclocking) is 133 MHz. That's much faster than GBA.

From looking at other cores, I get the impression that an ARM920T (allegedly ~1.1 DMIPS/MHz) at 133 MHz is right around the limit of what's realistic on a Cyclone V device. For example:

Code: Select all

VexRiscv linux balanced (RV32IMA, 1.21 DMIPS/Mhz 2.27 Coremark/Mhz, with cache trashing, 4KB-I$, 4KB-D$, single cycle barrel shifter, catch exceptions, static branch, MMU, Supervisor, Compatible with mainstream linux) ->
    Artix 7     -> 180 Mhz 2883 LUT 2130 FF 
    Cyclone V   -> 131 Mhz 1,764 ALMs
    Cyclone IV  -> 121 Mhz 3,608 LUT 2,082 FF

That being said, the closest point of comparison will probably be the DS core (ARM946E-S at 67 MHz) once that comes out.