int e l 3.7 DESCRIPTION OF EPROM FILE COMMANDS COMMANDS: PROG5(cr), PROG6(cr), FPROG5(cr), FPROG6(cr) (VERSION 1.1 ONLY) ACTlON TAKEN: PROG5 & FPROG5 The PROG5 command saves both the baud rate information and the MTOP information, just like the PROG3 command previously described. However, during a RESET or power-up condition the MCS BASIC-52 device examines external data memory location 5FH (95 decimal). If the user has placed the value 0A5H (165 decimal) in this location, the MCS BASIC-52 device will not clear the external memory during a RESET or power-up condition. This permits the user to "save" programs in external memory, providing some type of battery back-up scheme has been employed.
Normally, when using the PROG5 command to establish the RESET or power-up condition, the MCS BASIC-52 device will enter the command mode after RESET or power-up. However, if the user wishes to execute the program stored in external memory, the character 34H (52 decimal) needs to be placed in external memory location 5EH (94 decimal). Placing a 34H in location 5EH causes MCS BASIC-52 to enter the "RUN TRAP MODE." Details of this mode are presented in chapter 8 of this manual. PROG6 & FPROG6 Does the same thing as PROG5, but CALLS external program memory location 4039H during a RESET or power-up sequence.
This option also requires the user to put the character 0A5H in external memory location 5FH to insure that external RAM will not be cleared during RESET or power-up. The user must put an assembly language initialization routine in external code memory location 4039H or else this RESET mode will crash. When the user returns from the customized assembly language RESET routine, three options exist: OPTION 1 FOR PROG6 If the CARRY BIT is CLEARED (CARRY = 0) upon return from the user RESET routine MCS BASIC-52 will enter the auto-baud rate determining routine.
The user must then type a space character (20H) on the terminal to complete the RESET routine and produce a RESET message on the terminal. OPTION 2 FOR PROG6 If the CARRY BIT is SET (CARRY = 1) and BIT 0 of the ACCUMULATOR is CLEARED (ACC. 0 = 0) MCS BASIC-52 will produce the standard sign-on message upon return from the user supplied RESET routine. The baud rate will be the one that was saved when the PROG6 option was used. OPTION 3 FOR PROG6 If the CARRY BIT is SET (CARRY = 1) and BIT 0 of the ACCUMULATOR is SET (ACC. 0 = 1), MCS BASIC-52 will execute the first program stored by the user in EPROM (starting address of the program is 8010H) upon return from the user supplied RESET routine.
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