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Leonard Silva de Oliveira
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315-5235 sighting & correction to memory paging chips page from S8-Dev Team
 Posted: Mon Aug 28, 2000 3:22 am
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Firstly I'd like to report a 315-5235 sighting in the R-Type game cartridge. It consists of the mapper chip (315-5235)
and a 512kb rom that has the same pinout of a 27c4001 eprom. It's mpr code is MPR12002-T. Because the board had
the same pinout of a standard EPROM, I was able to use 128, 256 and 512kbytes EPROMs in it.
And more important, I was able to figure out how to connect a 8kbytes SRAM for backup (Phantasy Star). By doing that,
I discovered function of 3 pins that were unknown in the memory paging chips document from S-8 Dev Team
315-5235
PIN 24 - output pin. goes to SRAM output enable (/OE)
PIN 29 - output pin. goes to SRAM write enable (/WE)
PIN 30 - output pin. goes to SRAM chip enable (/CE)
315-5235 controls a 6264 SRAM (8kbytes). I don't know if it supports 16kb or more of SRAM.
I also had to add a SRAM power watchdog circuit and a lithyum battery in order to keep the data safely written on it.
This cartridge is being used with a ST G27C4001 (512kb) eprom burned with the japanese version of Phantasy Star.
I also used a MX28F1000PD (128kb) and a i28F020 (256b). All of them works perfectly without jumpers, straps and
such stuff ...
I hope I'm being usefull !
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