The Pro/File–AERCO Connection

Linking Pro/File’s data management capabilities with the rapid access and large capacity of a disk system is probably the single greatest improvement you can make to ZX PRO/FILE. If you obtain a disk system manufactured by AERCO you can make these modifications to PRO/FILE to pack your data base with enormous whollop. Here is what you get if you use a 16K RAM:

• Each disk holds 16 different programs.
• Any one of them can be accessed in under five seconds.
• PRO/FILE’s Main Menu tells you which program is currently in the computer, and
• Gives you the option to either LOAD a new data base or SAVE an updated one.
• The Display Option Menu gives you similar capabilities. A new selection, “D” (for disk) has been added.
• The disk operating system (DOS) is stored on the disk and: is always accessible simply by LOADING it. This DOS contains a directory or index which lists the names you choose to give to each copy of PRO/FILE.
• One “page” of the 16 which are on each disk is left blank. This is where you can put other frequently used programs. You could even store a 15th copy of PRO/FILE on this page if it is needed.

With capacity like this in addition to the 5 second loading time for any PRO/FILE on the disk, you will have a file manager that can hold its own against any other file manager on the market for any other computer and you will have spent just a tiny fraction of what it would cost to get the equivalent for a different brand of computer.

To run the cassette version of PRO/FILE on the AERCO system, several important changes are necessary. In the machine language, the address of FILE PEEK (16507 and 16508 decimal, 407B and 407C hex), the variable which stores the address of found files, must be changed because the drive software also uses these bytes. The new address for FILE PEEK will become 16622 and 16623 decimal. This pair of bytes is located in one of PRO/FILE’s REM lines and is not used for machine language.

As you scan the machine language listing given in the manual, every reference made to the old FILE PEEK (407B) is changed to 40EE which is the hex equivalent of 16622 decimal. A total of nine bytes need to be changed to accomplish this. Load the PRO/FILE cassette and BREAK from the main ZX menu. Then make the following POKEs:

POKE 16591,238 
POKE 16626,238 
POKE 16643,238 
POKE 16662,238 
POKE 16690,238 
POKE 16696,238 
POKE 16719,238 
POKE 16785,238 
POKE 16892,238

Translated into hex, these represent addresses 4OCF, 40F2, 4103, 4116, 4132, 4138, 414F, 4191, and 41FC respectively. All are given the hex value of EE.

BASIC program lines are added or altered to facilitate accessing the disk drive. The extra memory required to hold the new lines plus the need to free up 512 bytes for use by the drives themselves makes it necessary to reduce capacity of D$ to 10120 characters. Follow the instructions given in the manual or in UPDATE No. 1 to do this. Then add or edit the lines shown in figure 1.

A new BASIC variable, called F, is used by the disk version to tell the computer which “file” is currently loaded in the machine. When you wish to SAVE or LOAD onto the disk, this variable is also responsible for making the correct USR call to the disk ROM software. (See lines 9050 and 9100)

After you make the program changes, but before you save the program on disk, initialize the variable F by typing in the immediate mode:

LET F=2 and ENTER

Then run the disk initialization routine as shown’ in the disk operating manual:

RAND USR 12865 (for double density)

Once done, GOTO 17 to get back to the main menu. Type SAVE from this menu and the program will go onto page 2 of the disk. To make more copies on different pages, break from the main ZX menu and type:

LET F=3 and ENTER

GOTO 17 again, type SAVE, and the program goes onto the third page of the disk. Repeat this sequence for each disk page you want.

To use the disk PRO/FILE, power up the computer and activate the disk by typing:

RAND USR 13303

This loads page 1 of the disk. From here you can select which PRO/FILE you want and in 5 seconds it will be loaded into your computer. With the disk PRO/FILE loaded, you can load a different one by typing LOAD from the main menu. The program asks if you need to re-save the Current program, and then asks you which file you wish to load. Any of the 16 possible pages on the disk can thus be loaded.

DISKS AVAILABLE: If you feel that you could benefit by having PRO/FILE work on disk, but you lack the courage or ability to make the necessary changes, you can purchase the disk version of the program, including an expanded 5 pages of explanations for $39.95. To order write to Thomas B. Woods, PO Box 64, Jefferson, NH 03583.

A complete disk system, including a free copy of the disk PRO/FILE can be obtained from 21st Century Electronics, 6813 Polk St., Guttenberg, NJ 07093 tel: 201-869-2616.

9000 IF X#="SAVE" THEN GOTO 9100
9005 PRINT AT 16,0;Q$;Q$:Q$;Q$;Q$;Q$;AT 18,0;"HAS THIS FILE BEEN SAVED? (Y/N)"
9010 INPUT X$
9015 POKE 16390,4
9020 IF X$="N" THEN GOTO 9100 
9025 IF X$<>"Y" THEN GOTO 9120
9030 PRINT AT 16,0;"SAVE COMPLETE" ;Q$;Q$;Q$;AT 18,0;"INPUT FILE
NUMBER YOU";TAB 0;"WISH TO LOAD" 
9031 POKE 16390,0
9035 CLEAR
9037 LET Z$="00000"
9040 GOSUB 1200
9045 IF VAL Z$>16 THEN GOTO 9040
9048 LET F=VAL Z$
9050 RAND USR (12290+F)
9060 GOTO 17
9100 RAND USR (12720+F)
9110 IF PEEK 16390=4 THEN GOTO 9030
9120 POKE 16390,0
9130 GOTO 17

18 PRINT "zx pro\file FILE;F,,,"enter a search command   ","or type "a" to add       ",""save or "load" for disk","SPACE OPEN: ";LEN D$-P:" SLOTS";AT 10,0; "SEPARATE MULTI-WORD", "COMMANDS WITH A ""/""",,,"TYPE  ""AUTO"" FOR AUTO-SEARCH"
25 IF X$="SAVE" OR X$="LOAD" THEN GOTO 9000
35 IF X$(LEN X$)="/" OR LEN x$>28 THEN GOTO 18
220 PRINT AT 16,0:"hit enter to continue searching,"c" to copy,
"d" to load disk, "r" to return to previous files,"e" to edit this file, "n" to begin a new file search "
235 IF Y$="D" THEN GOTO 9005