Rare Hardware: Who has a DTL-H2000 dev-board?
Posted: April 29th, 2016, 5:18 am
Does anybody have a DTL-H2000 dev-board? Or knows somebody having one? That boards are the oldest known working PSX prototypes, and they are having still undumped cdrom firmware EPROMs. Getting that firmware dumped might be interesting for history/curiosity. For example, the firmware appears to be running on a CPU with different instruction set as in later PSX retail models, and there seems to be a real-time clock attached to the cdrom controller, so there should be at least some minor differences to later PSX models.
If somebody does have that hardware, and hesitates to dump the chip: Let's jump on the ROM-rot-panic train: Normally hardware won't rot away too soon. But then, these boards have the firmware stored on EPROMs, and, exposed to sunlight that memory can get erased in a few weeks/months. With the protective sticker it may last longer, although that might depend on wheter the sticker is made of plain paper, or if it contains some metal foil. I don't really know if EPROMs could last dozens or hundreds of years, but sooner or later it might come in handy to have some backup-dump so you could "refresh" worn-out/self-erased EPROMs if neccessary.
Tech info: The firmware is located on a (socketed) 32pin PLCC EPROM, so it should be very easy to remove the chip, and dump it using whatever dumping utilities you might have. However, observe that the pinout might be different as expected; the exact pinout can be found in the CXP82300 datasheet, http://www.datasheetarchive.com/CXP82300-datasheet.html - it's almost standard pinout, just with four NC pins inserted at weird locations - but the pins could be easily "shifted" to their normal locations via a simple adaptor.
For DIP chips, EPROMs exist in 28pin/32pin packages (depending on their capacity). For PLCC chips, EPROMs do always use 32pin package (but with different pinouts, depending on their capacity). So, if you want to use a PLCC-to-DIP adaptor for dumping, then you will need a 32pin/PLCC-to-28pin/DIP adaptor. A 32pin/PLCC-to-32pin/DIP adaptor won't work (although, if you have such a thing, then you could combine it with a32pin/DIP-to-28pin/DIP adaptor; that would require custom wiring, but DIP-to-DIP wiring should be easier than PLCC-to-DIP wiring).
If somebody does have that hardware, and hesitates to dump the chip: Let's jump on the ROM-rot-panic train: Normally hardware won't rot away too soon. But then, these boards have the firmware stored on EPROMs, and, exposed to sunlight that memory can get erased in a few weeks/months. With the protective sticker it may last longer, although that might depend on wheter the sticker is made of plain paper, or if it contains some metal foil. I don't really know if EPROMs could last dozens or hundreds of years, but sooner or later it might come in handy to have some backup-dump so you could "refresh" worn-out/self-erased EPROMs if neccessary.
Tech info: The firmware is located on a (socketed) 32pin PLCC EPROM, so it should be very easy to remove the chip, and dump it using whatever dumping utilities you might have. However, observe that the pinout might be different as expected; the exact pinout can be found in the CXP82300 datasheet, http://www.datasheetarchive.com/CXP82300-datasheet.html - it's almost standard pinout, just with four NC pins inserted at weird locations - but the pins could be easily "shifted" to their normal locations via a simple adaptor.
For DIP chips, EPROMs exist in 28pin/32pin packages (depending on their capacity). For PLCC chips, EPROMs do always use 32pin package (but with different pinouts, depending on their capacity). So, if you want to use a PLCC-to-DIP adaptor for dumping, then you will need a 32pin/PLCC-to-28pin/DIP adaptor. A 32pin/PLCC-to-32pin/DIP adaptor won't work (although, if you have such a thing, then you could combine it with a32pin/DIP-to-28pin/DIP adaptor; that would require custom wiring, but DIP-to-DIP wiring should be easier than PLCC-to-DIP wiring).
