A Megadrive core?

Time to talk about what other machines can run on the Next hardware!
Post Reply
SamusDrake
Posts: 252
Joined: Mon Jun 26, 2017 10:11 pm
Contact:

A Megadrive core?

Post by SamusDrake » Mon May 28, 2018 4:53 pm

Would the Next's Spartan 6 FPGA be able to handle a Megadrive core? If so, how difficult would it be to set it up?

Cheers.

User avatar
intrepidis
Posts: 3
Joined: Tue Jan 22, 2019 4:39 pm

Re: A Megadrive core?

Post by intrepidis » Mon Aug 12, 2019 7:09 pm

I don't know for sure, but just governing from the specs of each machine I'd say no. The main reason: the MegaDrive CPU is 16-bit and has many more instructions (including variants such as move.w and move.l, etc). So I'm guessing the ZX Spectrum Next FPGA isn't powerful enough (i.e. have enough space) to handle it. I'd love to be proven wrong though. Unfortunately it'll probably be eight years before this post is answered, lol.

biged
Posts: 1
Joined: Fri Dec 08, 2017 11:33 am

Re: A Megadrive core?

Post by biged » Mon Aug 12, 2019 7:41 pm

Might be a close-run thing. The Next has a Xilinx LX16, and the FPGAgen project seems to be near, or just over, the limit of fitting on a 20k Altera device. Let's say those two might be broadly comparable - everything depends on how well the respective synthesis tools manage.

I think the FPGAgen would be the starting point - there are many forks.

Tau Ceti
Posts: 11
Joined: Fri Jul 07, 2017 3:00 pm

Re: A Megadrive core?

Post by Tau Ceti » Tue Aug 13, 2019 4:25 am

Could a Mister / DE-10 Nano handle a ZX Next Core?

User avatar
SevenFFF
Posts: 222
Joined: Mon Jun 05, 2017 5:30 pm
Location: USA

Re: A Megadrive core?

Post by SevenFFF » Tue Aug 13, 2019 8:35 pm

For sure, the MISTer is a very beefy system. The Next core doesn’t yet have a SDRAM controller, as the Next uses SRAM, so it would need a fair bit of work and testing beyond simply synthesising for Altera.
Robin Verhagen-Guest
SevenFFF / Threetwosevensixseven / colonel32
NXtel Spectron 2084blog

dave18
Posts: 86
Joined: Tue May 30, 2017 1:06 am
Location: Bristol, UK

Re: A Megadrive core?

Post by dave18 » Wed Aug 14, 2019 12:07 am

For clarity, the response above is saying that Mister could easily handle the Next core but that the Next hardware has issues, especially around RAM types in supporting a Genesis core?

User avatar
SevenFFF
Posts: 222
Joined: Mon Jun 05, 2017 5:30 pm
Location: USA

Re: A Megadrive core?

Post by SevenFFF » Wed Aug 14, 2019 12:10 am

No. The Next hardware has SRAM and the MISter hardware has DDR3 and optional SDR SDRAM.

The Next core is made for the Next hardware and SRAM. Not for the MISTer hardware. The Next core won’t run as designed on the MISTer without work on the core. An SDRAM controller would be part of the FPGA core program not the physical board.

Nothing to do with Genesis. I was answering the question about Next core running on MISTer hardware.
Robin Verhagen-Guest
SevenFFF / Threetwosevensixseven / colonel32
NXtel Spectron 2084blog

dave18
Posts: 86
Joined: Tue May 30, 2017 1:06 am
Location: Bristol, UK

Re: A Megadrive core?

Post by dave18 » Wed Aug 14, 2019 12:21 am

OK, thanks. In my limited experience memory timing (especially syncing memory reads to the video beam) is the difficult bit everything else is relatively easy. Makes sense that a change of memory type would create a lot of reworking of the core.

Post Reply