SIMHC12 Change History

New features (May 2005):Instruction tracing, display of source code, and ability to set memory and code starting addresses using source labels was added. Substantial speed improvements were made as well.

New features (January 1, 2004 version): CALL instruction with extended addressing now puts correct return address on stack. (Almost all users don't use the CALL instruction, so the problem wasn't detected for years!) Parallel port display has cosmetic corrections.

New features (August 3, 2003 version): Added ability to change value of INITRG, INITRM, INITEE, and MISC from GUI even if otherwise not able from program because it had been changed once. Added simulation for 68HCS12 temporarily until real HCS12 simulator finished.

Fix (June 26, 2003 version): Certain combinations of Java runtimes and operating systems would not refresh the memory display properly after execution was halted via an uncaught interrupt or breakpoint. It's now fixed.

Fix (January 12, 2003 version): Fixed operation of CALL instruction and dissassembly of CALL instructions using indirect addresing mode.

Fix (October 13, 2001 version): Enabled operation of A, B, and D parallel ports in single chip mode.

Fix (August 19, 2001 version): Corrected dissassembly display of pre-decrement indexed mode.

New features (July 17, 2001 version): Added "64K RAM mode" where a system with 64K of external RAM is simulated. Program now gives a usage message when given improper arguments. Some small documentation revisions were made.

New features and fixes (June 2, 2001 version): Condition codes were not being set in the MAXA MAXM MINA MINM EMAXD EMAXM EMIND and EMINM instructions. FDIV fixed where msb of dividend was a 1. Changes made in January disabled the 68HC812A4 Single Chip mode and caused errors in the value of the MODE register. These problems has been corrected.

New features and fixes (April 3, 2001 version): Optional binary (instead of ASCII) display in SCI viewer. Optional display update while simulating execution. Jar file is now directly runnable ("java -jar") under JRE 1.2 or later. Often requrested EQUATES.ASM and DBUG12.ASM files are now supplied in the distribution.

New features and fixes (January 2001 version): Added support of INITRM, INITRG, and INITEE registers to allow altering memory map. Fixed broken EEPROM programming in 68HC912B32 mode.

New features and fixes (December 2000 version): Simulation of 68HC912B32 in single chip mode added (no PWM or SPI). Additional parallel port support added for ports A, B, and D when simulation run in Narrow Memory or Single Chip modes.

New features and fixes (September 2000 version): Function generator (squarewave/pulse) for Timer Input Capture, port T. Added new operating mode which doesn't reset RAM memory at "power-up". This called "request mode" because it was requested. It is now easier to alter the contents of memory locations and the Terminal Emulator is a realistic 80x25 dumb terminal. A few cosmetic and documentation changes were made.