A FEW NOTES ON PROMFORM 5/1/85 This paper is just a few quick notes about the PROMFORM program for use with the EPSON GENEVA PX-8. I'm sorry to say that this paper had to be written in such a rush, but the COMDEX Trade show is next week and I just can't take the time required right now to write all the things that need to be said. This paper will just be a few words on PROMFORM that you should know. The Geneva does not have the hardware within itself to burn EPROMs. In order to make your own ROMs for the PX-8, you must have a EPROM Burner that can accept Intel Hex File Format as the source for the ROM image. All that the PROMFORM program will do is take the files that you wish to burn into ROM, put them into the proper format (with a directory), and generate the Intel Hex file that would be down loaded to your ROM Burner. With PROMFORM you can generate 8K byte (2764), 16K byte (27128), or 32K byte (27256) EPROMs for use with your Geneva. In addition, if you need more ROMing space, you can generate 2 ROM images for ROM sets (2-8K, 2-16K, or 2-32K ROMs). With a 2 ROM set, 2 ROMs are ganged together to act as one large ROM. For example, 2-32K ROMs would act as a 64K ROM. ROM number 1 would be placed in drive B: and ROM number 2 would be placed in drive C:. Drive B: would show 64K bytes of files and drive C: would not exist because the directory information is only in drive B:. An 8K ROM can hold 7K or 8K of programs. An 8K ROM can hold 8K of programs as long as the last group (1K block) of the last file does not take up the full 1K. The answer of how do we put 8K of programs and a directory into 8K is simple. First a directory may take up anywhere from 128 bytes to 1K. A 1K directory is unlikely, that would be 31 files on the ROM. The ROM header takes up the first 32 bytes of the ROM. It holds such information as the ROM's name, date, version number, the size of the directory (in 128 byte sectors), and the size of the ROM. Each file listed in the directory requires 32 bytes and looks the same as a disk directory. The first directory sector holds the header information and the directory information for 3 files. If there are more than 3 files, additional sectors are added to the directory at 4 files per sector. Imagine the directory sectors pushing the file groups (blocks) to higher addresses within the ROM. Each block is 1K in size except for the last one which is 1K - the size of the directory. As long as the last block used on the ROM does NOT require all the sectors within that block, 8K of files will fit on an 8K ROM. You may wish to use the STAT program to see the real size of your file. Remember, the number of records * 128, gives you your file size in bytes. The EPROM must be mounted on the plastic carrier. This part comes from Molex; however you might be able to purchase this part from electronic supply houses. 1 A few words of warning to those who will be making ROMs: 1) PROMFORM is given out AS IS. This program was written as a quick and easy way of making the ROMs for the Geneva. It is NOT well written and I know for a fact that there ARE SEVERAL BUGS in the program. 2) PROMFORM works best on the PX-8. I have run PROMFORM on other CP/M systems, but have found that sometimes the ROM image is garbage beyond 16K. This problem doesn't seem to happen when it's run on a PX-8. 3) If the last sector of the last block is used, the last byte on the last sector is garbaged. Most of the time this won't matter, because the program ends before that last byte and the rest of the sector was just filled with zeros. However if you do need valid data in that last byte, you will need to patch the ROM image. 4) I don't have the source code to this program, so Epson America can't hand it over to you. (This program was written by Epson Japan.) 5) NEVER assume that just because you run PROMFORM and burned an EPROM, that the ROM files are correct. Take it from the man who had to create the ROM image for dBASE II, DB Traveler, Portable TelMerge, Teledex, The Traveler's Pak (EXPMGR, TIMMGR, & APPMGR), Geneva Connection, and others: Only a fool believes that, "Nothing can go Wrong!" I have seen both PROMFORM and my EPROM burner create bad ROM images many times. The only way to be sure that is was a good burn is to verify the results. Run a file compare program or use the file compare function of PROMFORM. 6) NEVER use an NMOS ROM in drive I: of the Multi-Unit. Use a CMOS EPROM, such as a 27C64 or a 27C256. You may use NMOS or CMOS ROMs in drives B: or C: I hope that you will have lots of fun with your Geneva putting Public Domain software (or your own stuff) onto EPROM. Maybe PX-8 users will set-up some type of interaction with other PX-8 users who don't have EPROM burners, so that EPROMing won't be limited to just a lucky few. ************************* * * * Mr Bob, Epson America * * * ************************* 2 .+.mB8ܝ=