Tuesday, May 8, 2012

JMON Enhanced for EEPROM

To accomodate the 16K memory card when using EEPROM, I added a write delay ("W") command to my JMON monitor program so that you can specify a delay after writes, which is needed when writing to EEPROM. It is used for the COPY, FILL, and TEST commands. Typically 28C64 EEPROM chips needs anywhere from 0.5 ms to 10 ms for a write to complete, depending on the chip manufacturer.

I used the delay routine from the Apple II ROM monitor, which is well documented in the book "Assembly Cookbook for the Apple II/IIe" by Don Lancaster.

With that change, I can copy data from RAM to the EEPROM or run the memory test on EEPROM from JMON.

JMON with New Write Delay Command

Below is a screen shot running my Replica 1 port of OSI BASIC. It is running out of an 8K EEPROM with a 8K RAM chip installed so the system has 40K of contiguous RAM.

OSI BASIC with 40K of Available Memory

No comments: