for Errors message and disables the final output to the line printer. Scripsit thinks it outputs the document twice, once for each pass. If the first pass through is successful (no errors are found), the line printer is enabled. The whole output routine repeats, this time slowed substantially by the printer's operation.

Miscellaneous Information

The information in Figs. 7, 8 and 9 explains Scripsit's memory usage. Figure 7 shows where all messages output to the video display are stored. As you can see, they are well distributed throughout the whole program.

Figure 8 shows all the unused memory areas I have found in Scripsit. Program modifications can be placed in these holes without interfering with normal program operation. This is especially true in the 389-byte hole located at 7AA5H. Two of the holes shown on this diagram need further explanation. The first, at 5202H, is the Radio Shack copyright message coded in ASCII. If, when modifying Scripsit, you make the entry point 523FH, you will have a total memory area of 63 bytes for your mods.

The second unused memory area is 31 bytes long, starting at address 584BH. I don't understand why this hole is thereā€”it appears to be some kind of table but I cannot find a reference to it. Any ideas?

Besides the command lookup tables I discussed earlier, Scripsit includes parameter tables, RS-232 baud rate tables and character replacement tables, to name a few. Figure 9 shows the address of all tables, along with a description of what they contain. This list is extremely handy in interpreting data during disassembly.

Figure 10 is a list of important routines and where they reside in Scripsit. This is not meant to be an exhaustive list with detailed memory and register


Message location

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