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Could finally write a file to my SD card :]

Written by cafealpha 3 comments
I could finally write a file to my SD card ... from my Saturn
Well, I just tested by dumping my Saturn's BIOS, and didn't tried further, because I don't want to find and fix other bugs today

Top : my Saturn BIOS, dumped from my Freewing device 5 years ago
Bottom : BIOS file in my SD card dumped today
Hex Editor says that both files are identical

This fixes a nearly 3 years old bug
At that time, I connected a SD card to my second pad port on my Saturn and could read files successfully. However, file write sometimes failed ... I thought about many possible causes of failures (not enough 3.3V power supply ? Bad luck ? etc etc), but it was a software bug : writing sectors to SD card actually takes longer than reading sectors, and I didn't waited enough for my SD card to finish write.
Changing poll timeout count from 500 clocks to 50000 clocks seems to fix the problem. (Q&D fix, but if it works fine, I won't change it )

So now, as SD card read/write access works on both yabause and real hardware, it is time to to use it in order to develop new features for my Saturn

My SD card cartridge for Saturn (Q&D prototype revision )

Edit : wow, current cartridge firmware build ID (incremented on each make/build) is 4200


#1  - hitomi2500 said :

Congratulations! Is that a hippo in the bottomleft corner? And is that a MAX3000? They're almost as ancient as saturns themselves (CPLDs, not hippos).

#2  - cafealpha said :

@hitomi2500 : Hi, well, it is a cow, but it could be anything else because of poor rendering on PCB silkscreen :D

#3  - cafealpha said :

@hitomi2500 : And yes, it is a MAX3000 CPLD, "the simpler the better", and this CPLD is kind enough to offer 5V <-> 3.3V interface. This cartridge mostly uses ancient parts, because I don't have enough experience with modern ones ^^;


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