Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

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Ian Micheal
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#11 » Fri May 28, 2021 5:04 pm

Nico0020 wrote:Cool! I always wanted to see more homebrew find wags to use the serial port. Iirc Sturmwind used it to save replays and potential dlc.

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Thats a great idea we should see more retail or not homebrew use it since atomis wav ports many have serial port reader i dont see why at about $15 now with the nice metal connector versions indie dev's selling homebrew cant use the feature or even included one as a SE edition .. having unlimited write space vs small vmu just makes more sense.. many possible uses for games and new features .. but it's left as a nothing ..

Main advantage is you can be in two places at once at the same time.. you cant do this on gdemu or gdrom or cdr..

so stream or load from ether at the same time no stop start.. years i got it's to slow .. cant believe people forget it's as fast a ps1 cdrom drive if you cant find that useful to dreamcast having a pretty much 2 cdrom drives a slower one that can read right and a fast one that is read only.. i guess i dont know what to tell you..

Going to start a github page with how to use fat32 read write show simple examples of use and how with out it these things are not possbile..

SMiTH
Black Mesa
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#12 » Fri May 28, 2021 5:07 pm

this is a very smart solution.
great work ian.
this might open up many possibilities for improving homebrew.

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dubcity
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#13 » Fri May 28, 2021 6:04 pm

in my opinion could be the biggest technical breakthrough this year for dc...

Docteh
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#14 » Fri May 28, 2021 10:42 pm

Does the speed of the SD card matter, or is the SPI bus the bottleneck? (1 bit vs 4 bit for regular SD card protocol)

A modern example of why you'd want these faster random reads might be the Call of Duty games, from a hard drive its faster for the modern consoles to have an entire copy of textures for each level and read that in as a large linear chunk, rather than go and get the specific assets from a central location.

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willis
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#15 » Fri May 28, 2021 11:56 pm

Ian this is some great work/news! Congrats!

Without knowing too much of the technical side of it, but could this be a potential fix to getting other games playable on the Dreamcast that weren't possible? Games like Quake 2 that technically could run but run out of memory. Could this alleviate that issue??

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Anthony817
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#16 » Sat May 29, 2021 2:12 am

I asked is this was possible around 2011 or so when Chui had updated his emulators to support the SD card reader. People called me crazy and said it was not possible to use it for memory for Neo Geo MVS and AES emulation. Is that still true or do I get to have the last laugh now? XD

I am so surprised the things this community manages to keep putting out and making the console do things people laughed and said was always impossible, but this past decade has proved so many people wrong! I am hopeful this can be used with the SM64 port, or a fork of it! Too bad this can't be used on retail games like Half-Life and mods haha! But open sourced projects can REALLY shine with this! Duke Nukem 3D here we go!

Ian is the gift that keeps on giving, seriously dude. Great work brother!
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Ian Micheal
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#17 » Sat May 29, 2021 5:42 am

Anthony817 wrote:I asked is this was possible around 2011 or so when Chui had updated his emulators to support the SD card reader. People called me crazy and said it was not possible to use it for memory for Neo Geo MVS and AES emulation. Is that still true or do I get to have the last laugh now? XD

I am so surprised the things this community manages to keep putting out and making the console do things people laughed and said was always impossible, but this past decade has proved so many people wrong! I am hopeful this can be used with the SM64 port, or a fork of it! Too bad this can't be used on retail games like Half-Life and mods haha! But open sourced projects can REALLY shine with this! Duke Nukem 3D here we go!

Ian is the gift that keeps on giving, seriously dude. Great work brother!


Thanks mate I think you have to think more of saving then having more ram.. say quake doom is loading pak file into system ram that takes that amount before it can reading it reducing the amount you can load at once.. if you load direct from the sd card you have not filled system ram with loading that said file.. main use at first is cdda streaming music on the cdrom and loading pak files or game files from the sd card get rid of the age old problem of cant read and stream 2 things at once.. Most pc games where not made to run from optical disk.. How we got around that is loading it and keeping it in system ram then reading the disk.. As you can see this cuts down on your main system ram .. just so you can do 2 things at once..

Main use at the start for me is this developing virtual memory driver for what your talking about will take some time and skill.. offloading file loading of main games files to the sd card means you have super fast main drive to load or stream music..

Main uses but I'm working on that.. Your not adding ram at this point like a virtual memory driver.. it's a ram cache with read write..

Think right now saving system ram by not caching or hold files in memory just because you had to before because you cant read from 2 places at once..

Other more complex uses are possible down the track as i learn more how a virtual memory driver could be coded and used with read write space.

As you could understand this not something i have had a lot to do with since my main console has never had that in mind. Or apart from sega zip disks

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Ian Micheal
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#18 » Sat May 29, 2021 7:08 am

I have a new video just about to up load showing full 100% stereo streaming from the cdrom and all games files loading from the sd card no stutter no stop start full 2 places at once parallelism tech

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Ian Micheal
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Re: Using the Serial port reader as ram cache DOOMDC 640x480proof off concept

Post#19 » Sat May 29, 2021 7:48 am

RAM CACHE SD parallelism DOOM FULL STEREO SOUND CDDA LOADING 2 PLACES AT ONCE TECH DEMO DREAMCAST




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