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PPcenter. Arts and craft for my Sega Saturn. Since 1847 :D

Merry New Year !

Written by cafealpha 6 comments
I sometimes check this blog in order to verify if there are some interesting news, without success, and then I realized that I am the only author of this blog (), hence though I should write something here in order not to deceive my countless fans.

So, sorry for the lack of news recently, I was busy with Saturn things, but also in deciphering Christmas presents lists ... and now busy in tidying up lego blocks and trashing used wrapping paper

I hope you're spending nice Christmas vacations ! I'm a little late for wishing you a merry Christmas ( ), and a little early to wish you an Happy New Year ( ), hence the broken title


So what's new with my Saturn projects ? In fact, nothing worth writing an article, but here is a short (and probably incomplete) list anyway :

 1. SD Memory Cart : when overwriting save on Saturn side, keep the old save file on SD card (but remove it from saves list, of course).
Basically, it automatically keeps old saves somewhere on SD card, so that it is possible to revert to a previous state. I hope Saturn RPG fans will like

 2. USB dev cart mode : when USB cable is detected, allow to unlock CD-ROM and then prompt for data upload.
This feature allows to makes tests on Saturn main program using data from CD-ROM without the need of installing a modchip, and without the need of burning a CD-R on each program changes
Special thanks to Shazz for reminding me to add such a feature, antime for wiring FTDI's PWREN signal to Saturn (it was unused for 3 years, but it was useful in order to detect USB connection, and hence hiding USB dev mode for normal users not using USB), and of course CyberWarriorX and jhl for Pseudo Saturn

 3. PCB changes : basically removing few debug "in case of" stuff, and also moving SD card socket in order to fit better with cartridge shell.
It is still WIP, but plan to send the updated gerber to the PCB house on next month.

 4. Few changes to the sources of yabause I'm using for testing my projects.
Especially, I added position save/restore and keyboard shortcut to each debug dialogs ... long time I wanted to do this

 5. In Backup Data Manager, some additions to "Import" feature : backup data dump file read and parse was done a while (4-5 months ?) ago, I just added something to select where (Internal Memory or Cartridge or Floppy) to save selected saves, and plan to port save data extract algorithm next month or so
Thanks to hitomi2500's ss-save-parser project, such "Import" feature is easy to integrate in my Backup Data Manager project


Last but not least, I also want to thank Stac user on Assembler forums
He's doing good job in beta testing, and thanks to his reactivity and good communication, project is progressing faster than I was expecting.
Beta testing is far from being a funny job, especially with me as main programmer (), and when testing requires to play games (this requires time, and bugs on my Saturn project may lead to loose of progress in game), so once more, thank you 

Read more Merry New Year !

Firmware development - will it work somewhere else than in my dev Saturn ?

Written by cafealpha 6 comments
I'm still developing the firmware for my custom cartridge, and it worked enough so that I could take a video of it running on real hardware


data/images/20151028_pskai_sdcard_test.jpg
Click on the image in order to see its youtube video.
You can also click here in order to download .avi file.


Video may be blurry, so here are some additional pictures :
data/images/20151029_testcart_usb.tb.jpg
USB & SD card cartridge.
This is the cartridge I mainly use for testing on real hardware
(USB port is used for debug purposes)


data/images/20151029_testcart_beta.tb.jpg
SD card cartridge for Saturn.
This is the version I plan to release in the case development continues well


data/images/20151029_flatcube_from_sd_card.tb.jpg
Flatcube demo loaded and executed from SD card.
This picture is here in order to put a link to the homepage of flatcube demo author


And last but not least, many thanks to beta testers for their cooperation and patience

data/images/20151028_pskai_bt2_saturn.tb.jpg
Beta cartridge loaded on modded Japanese Saturn.
Thanks to
MeteK for beta testing and taking this picture
Last week, MeteK reported that basic SD card access worked on his Saturn

data/images/20151028_pskai_bt1_screen.tb.jpg
Pseudo Saturn Kai System Information screen.
Thanks to Alexandre Souza from www.tabalabs.com.br
for beta testing and taking this picture 

data/images/20151112_tabajaralabs_noshell.tb.jpg - data/images/20151112_tabajaralabs_shell.tb.jpg
Additional pictures from Alexandre : cartridge without, then with shell.
Alexandre is currently trying to 3D print cartridge shells. Please do your best


I still can't getting things working on Alexandre side : SD card doesn't respond to SPI requests from Saturn via my cartridge ... I suppose this is due to a bad hardware design on cartridge side, but I still need to investigate about this ...

Edit (2015/11/11) : it is fixed and verified here
Fortunately, it was not an hardware error, but a firmware (SH-2 side) error.
About details : I access SD card by using SPI protocol, and the reason some cards couldn't be initialized was due to the fact that commands were incorrectly received by SD card.
Sending a dummy synchronization byte before sending command to SD card fixed the problem.
data/images/20151111_sdtest_satlink.tb.png
Log taken from my dev Saturn : first half is SD card initialization sequence,
and second half is data blocks reading.

data/images/20151111_sdtest_yabause_log.tb.png
It works under custom build of yabause too
Thanks to this, most of the tests could be done on PC,
which saved a lot of development time.
Thank you yabause team



After doing some testings on my side, I could verify that :
 - SD card access works fine on all the 6 Saturns I own
 - Some SD card can't be accessed via my cartridge, while the others work fine. (← fixed)

data/images/20151102_test_saturns.tb.jpg
Saturns used for testing.
The one on the top of the picture is my good old dev unit

data/images/20151102_test_sd_ng.tb.jpg
SD card that aren't recognized by my cartridge.
Edit (2015/11/11) : I fixed firmware and 32GB micro SD card above was recognized
(I didn't tested with the other SD cards, but I suppose it is now OK too.)

data/images/20151102_test_sd_ok.tb.jpg
SD cards that were correctly recognized by my cartridge.



To conclude this article, I have to say than this project doesn't make exception to Muphy's Law :
Anything that can go wrong will go wrong

Beginning of year (2015) : Virtual Memory Cart related debug. After verifying that it has the chance to work, I temporary stop its development, mostly because I was bored to continue development of this feature ^^;
Until this summer : a lot of struggle with Pseudo Saturn 0.831/0.832/flasher/etc related things.
September : SD card library related troubles. Try to get a solution by using -and trying to fix- thinfat32 library. Using fat_io_lib was a better choice, thank you hitomi2500 for your advice about this library
October ~ Now : Troubles with SD card on Alexandre side ... will work if another SD card is used (currently waiting for test results) ?

Anything that can go wrong will go wrong
But at least, beta cartridge half works, so I can safely continue its development


I plan to release the first batch of cartridges with SD card included, so that there won't be incompatibility issues on user side.
As my project is a low cost one, and also because it won't load commercial games, I plan to sell the cartridges with low cost (8GB or maybe 16GB) SD cards.
Edit (2015/11/11) : SD card compatibility is likely to be fixed, and as far as possible I don't want to do SD card stock management/etc, I will probably release cartridges only.
There still no release date to announce, because some fixes/features addition/testing/etc is remaining, and also because I mostly do this for fun

Read more Firmware development - will it work somewhere else than in my dev Saturn ?

Iso/Cue "loader" works on real hardware :]

Written by cafealpha no comments
(For more informations, you can also read this old article.)

I finally had time to use my Saturn, and I could verify that iso/cue "loader" works on real hardware !
Of course it works well when reading from RomFs, and it works also well when reading file from SD card

data/images/20150626_iso_loader.tb.jpg
My test environment ... sorry for the mess
(Micro SD card is located on top-left of the cartridge)

I lost some time to understand why data transfer from SD card was slower than expected, but finally understand why : some debug/whatever delay routine was called when accessing cartridge registers ...
Just putting some #if 0 around this delay code solved the "problem" ^^;

Read more Iso/Cue "loader" works on real hardware :]

Iso/Cue "loader" works :)

Written by cafealpha no comments
So I am making an enhanced version of Pseudo Saturn firmware.
And, as an extra feature of this firmware, I added an iso/cue "loader".
data/images/20150603_dr.evil.laser2.tb.jpg

Why the quotes around "loader" ? Because it doesn't emulates CD-block
So, it only loads few homebrew games, but it's enough for me, and I don't want to waste more time on adding CD block software emulator while better solutions (rhea, jhl's "mpeg" cart, etc) already exist.

As an other bonus, I also added RomFs support to my Saturn library
It is like romdiskfs that is widely used on linux, DS homebrew, etc, but it allows file compression, some other features, and ... is probably buggy because I coded it from scratch

(*) Virtual file system is not really new on Saturn homebrew scene, because Piratero already implemented one in libyaul a while ago


data/images/20150603_romfs_filelist.png
RomFs root folder contents. I will load sl_elf.iso file in the next paragraph.

So here is a capture of yabause running sl_elf.iso, after decompressing it from virtual file system stored in Flash memory.
sl_elf.iso is "satdemo" made by CharlesDoty, grabbed from SaturnOrbit's examples (Thank you Rockin'B for making SaturnOrbit ! After 10 years, it still have it installed on my laptop's hard disk ).

data/images/20150603_isocueloader.png
yabause running Saturn demo from iso file, near SatLink software I use in order to debug my Saturn programs.

Very big thanks to the yabause team ! I grabbed the iso/cue loading routines from yabause sources, and it was very easy to port them

Edit : I removed unused code (CD Block emulation routines, etc) from iso loader module, and .o size dropped from 74KB to 18KB oO

Edit (2015/06/26) : I tested this code on real hardware, and it works too ! Please see this article for more details.

Read more Iso/Cue "loader" works :)

Nostalgia time : ietx2 old (buggy) beta iso for download

Written by cafealpha no comments
After making some cleanup in my development folders, I found an old archive file
It is dated 2007 June 20, and contains a very early version of ietx2, which is an adaptation of yeti3D engine to Saturn.
At that time, I was using a PentiumIV processor and 80GB IDE hard disk in order to run sh-elf-gcc provided by SaturnOrbit ... very nostalgic times ... but I definitely prefer nowadays for Saturn development

Iso file can be found >>> here <<<.
(No, there are no sources available, because I didn't kept archives of sources at that time.)

Please don't waste a CD-R for this. You can try on yabause, or just look at screenshot and say "hey, very ugly stuff" however.

data/images/20150410_ieti01.png
ietx2 beta screenshot : not enough time to draw last quads in VDP1 list, hence the garbage on foreground.

data/images/20150410_ieti02.png
ietx2 beta screenshot : example of incorrect rendering when quads coordinates exceed 16 bits range.

Present version

You can find current version (ietx2) and sources of my Yeti3D adaptation here (dated 2011 April 19).
Also, there are videos of ietx2 available below. Click on the links to display them on youtube.
data/images/20150410_ietx2_01.png


Future (?) version

I'm still maintaining sources of ietx2.
I renamed project name to ietx3 (yeah, I'm not very original when choosing project names ), and now use a lite version of Yeti3D PRO engine ... "lite" means original, minus a lot of features, in order to keep a decent frame rate, and fitting to Saturn resources.
You can find some videos (binaries are not released, sorry) on my youtube channel :

Read more Nostalgia time : ietx2 old (buggy) beta iso for download

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