how to store a very large amount of data

[JD123]

32 bytes should be easy to store in the 877's ram.

What's the serial format? Is it sending 256 bit (32 bytes) as uninterrupted or unformatted bits?

My current project has MMC > PIC > I2C EEPROM (F-RAM) moving 4,096 bits (512 bytes) in a shade under 21ms, or an effective baud rate of close to 200k. I don't store the values in the PIC except for a 'working byte', I just pass them through the PIC. Depending on the serial format you're using, you may not need to store the data in PIC RAM if using a FRAM I2C EEPROM. If your serial format allows for data bus holds, you can use standard I2C EEPROM's and not have to store more than 1 or 2 bytes in the PIC at any given time.

It all depends on the serial format.