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Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Thu Jan 11, 2018 6:08 pm
by DR TEAMCAST
Roel wrote:
DR TEAMCAST wrote:i'm surprised to see nobody mentioning the idea of a 32mb+ VMU. i think that'd be around 6400 blocks or so. you can store 32mb in a pebble these days


Each block is 512 bytes, so you'd need 65536 blocks to reach 32MB. But that number can't be stored in 16 bits, it would overrun and turn to 0.

but i'm sure getting to at least 12mb or 16mb is possible yeah?

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Thu Jan 11, 2018 7:02 pm
by RXShorty
Awesome to see a new wireless controller with the official looks!
Sorry I like the Dreamcast controllers the way they are.
Depending on the price, I will get 4 of them :)

Verstuurd vanaf mijn BBB100-2 met Tapatalk

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 3:00 am
by Roel
DR TEAMCAST wrote:
Roel wrote:
DR TEAMCAST wrote:i'm surprised to see nobody mentioning the idea of a 32mb+ VMU. i think that'd be around 6400 blocks or so. you can store 32mb in a pebble these days


Each block is 512 bytes, so you'd need 65536 blocks to reach 32MB. But that number can't be stored in 16 bits, it would overrun and turn to 0.

but i'm sure getting to at least 12mb or 16mb is possible yeah?


The maximum value of a 16-bit number is 65535, but IIRC that number has special significance in the VMU filesystem, so you would only be able to address 65534 blocks at most. I'm going from memory here, but if I'm right that means the maximum possible storage space on a VMU (at least in theory) is 33553408 bytes, or 99.997% of 32MB (or 32 "MiB" for modernists). :D

I'd be surprised if even a single game (or the DC BIOS for that matter) supported such a VMU, though. It seems that, contrary to today's console manufacturers, SEGA had a very "laissez-faire" attitude. I like how tolerant SEGA is in general, but I wish they'd have been more strict about things like VGA, VMU and Arcade Stick support.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 3:13 am
by Aleron Ives
Even if the VMU can be that large, it's useless if games don't support it.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 3:29 am
by Tarnish
So it's not possible to make something like the 4x Memory Card, but with 50 or something pages cosisting of 200 blocks instead of just 4 pages?

So you wouldn't need a dozen VMUs to store all your saves? Tho switching between so many pages would probably be just as annoying as swapping out VMUs so..you might not win much with that approach either.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 4:59 am
by Aleron Ives
That would be a much more useful approach, as all games would support it. You could possibly have 8 banks with 2 rows of dedicated buttons to let you select each bank, instead of having to cycle through them one by one with a single button, as with the 4X cards.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 6:42 am
by Roel
Actually even the official 4X VMU isn't supported by all games. A standard VMU accepts data at fairly high speed, but the 4X VMU uses a slower storage medium. If a game tries to write data too quickly, the 4X VMU can't keep up. I ran into that problem with Rush Rush Rally Racing too, but I fixed it in Rush Rush Rally Reloaded.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 7:43 am
by Aleron Ives
Very interesting! I suppose that's because Sega used cheaper memory to reduce the cost of effectively selling four VMUs in a single unit.

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 7:53 am
by Tarnish
I heard that the 4x Memory Card isn't compatible with all games but never knew why that is. Good to finally hear the reason.

Aleron Ives wrote:Very interesting! I suppose that's because Sega used cheaper memory to reduce the cost of effectively selling four VMUs in a single unit.


Well you would think not including a screen, a speaker, dpad with face buttons and a battery holder would be cost effective enough but apparently it wasn't. Also you can't really class the 4x Memory Card as a VMU, since it's not exactly "Visual" without a screen. =P

Re: Retrobit sega partnership. New Dreamcast/ Sega hardware- peripherals.

Posted: Fri Jan 12, 2018 8:20 am
by Roel
I don't think cost was the issue here actually. Again, I'm digging up this information from memory, so I may be wrong, but if I recall correctly the 4x VMU's memory is much more dependable. It takes longer to write to, but it's also expected to retain the data decades longer than a standard VMU.