Software Review * LABORATORY MICROSYSTEMS Z-80 FORTH 3.0 for CP/M * by Richard C. Secrist Editor's Note: Since the publication of this issue over a year ago, LMI has updated their product making extensive changes to the documentation which now puts it into the superlative class... as of 1/8/85 the current release was Version 3.10. < OVERVIEW > Laboratory Microsystems Inc. (LMI) Z-80 FORTH version 3.0 is an 83-Standard Forth development system optimized for the Z-80 uP that runs as a task under CP/M. The disk and console interface make use of the host operating system and provide high level compatability with other LMI Forth implementations for various microprocessors. Z-80 Forth uses standard CP/M random access data files for screen storage, so its programs and data coexist on the disk with other applications and may be manipulated with standard system utilities. < UTILITIES > Z-80 Forth includes full screen and line editors, an assembler, decompiler, and extensive file I/O facilities. The full-screen editor uses Wordstar-like command sequences and is adaptable to sundry video terminals through the video attributes installation procedure. If you are either new to Forth or lazy the manual offers you an easy way out of configuring Z-80 Forth to your terminal by hand. Simply photocopy the cursor and attribute control section out of your terminal book and send it to them with your distribution diskette. Then LMI will return your disk via express mail with your terminal listed as one of the choices on the installation menu. This saves you the grief of having to do it yourself, and helps LMI out because their Forth now supports the XYZZY type terminal. This also configures your copy of Forth to take advantage of the various video-support words made available in Z-80 Forth (e.g. CLEARSCREEN, BLINK, UNDERLINE). The assembler uses standard Zilog mnemonics in the traditional Forth postfix style. Other assorted utilities include a decompiler, notable benchmarks, a non-destructive stack print routine, and even memory dumps in byte or word format. Software floating point and AMD 9511 chip support are available at extra cost. < EXTENSIVE FILE I/O SUPPORT > One of the most outstanding features of the LMI product is superior file I/O support. From within FORTH the programmer is given access to a very powerful complement of disk file and record interface routines. The routines are sufficiently powerful to allow you to get yourself into a lot of trouble, and LMI sprinkles the documentation with numerous cautions regarding what to watch out for. For openers, LMI includes a file access function word called FDOS that gives you direct access to 36 file operation primatives. There are also another set of extensions that "give you total control" for record-level I/O bypassing the FORTH internal disk drivers and virtual memory management features of the LMI FORTH altogether. LMI also supports binary overlays to link things like the editor into the dictionary as a one-shot. This is described in the documentation. < COST-FREE TURNKEY APPLICATIONS > LMI provides several boot-up literals to create custom pre-compiled FORTH applications using this product. No license fee is required as long as you seal-off the LMI F83 itself. They would of course appreciate some credit and a phone call to make sure you sealed everything up correctly. < SIMPLE MULTI-TASKING > Z-80 FORTH includes simple multi-tasking support for up to 10 background tasks. LMI allocates CPU to these tasks on a round-robin basis. In general, however, these tasks should not access the disk or keyboard and must of course leave the stack clean upon exit. < EXCELLENT DOCUMENTATION > The documentation is of excellent technical quality and content - something growing rarer in these torrid days of user-friendly coloring books. The LMI documentation has MEAT. From the internals section describing the formats of the dictionary formats of things like colon and "CODE" definitions, right down to a real index, I am very pleased with the manual. Although I am not trying to scare away beginners, the documentation and the generous extensions make this an excellent "hacker" FORTH. I do not mean to suggest that the newcomer to FORTH is neglected in the LMI manual, however. In fact, the manual contains an instructive and interesting "overview of FORTH" that is one of the most concise yet useful readings on FORTH I have seen anywhere. It does not make for light reading mind you, but ounce for ounce it may be some of the most useful text you may ever scan in terms of putting the language as a whole into a nutshell. The text would be extremely useful to the professional programmer who is just getting into FORTH. The documention also includes several useful appendicies including: 1) "Coping with the F83 Standard", 2) "Restrictions on an 83-standard program", 3) "Checklist for Program Conversion to Z-80 FORTH 3.0", and "Adapting STARTING FORTH to Z-80 FORTH 3.0". < USER SUPPORT > A word about support. Once I called them for support and got handed off to a knowledgeable analyst promptly, who did a very good job of fielding my questions. Another nice thing happened in my dealings with LMI to date: I purchased this product because I wanted a real FORTH for the Z80 and I noticed in their ad in FORTH DIMENSIONS a few months ago that it was still only $50. Well, I ordered it assuming (ass-u-me) that the ad price was right, and didn't verify this with the person who took my order (entirely my stupidity). Well, the next day my new issue of COMPUTER LANGUAGE came in the MAIL and the ad there pegged the LMI Z80 FORTH at $100. Confused, I called LMI back to ask them about it, and it turns out I did fubar it. LMI gave me a partial refund "to take some of the sting out of it". Now THAT'S service ! Not to mention the fact that the product is quite worthy of it's $100 price tag. Overall, I highly recommend the LMI product and will consider their version first when shopping for a FORTH for other processors. [rcs]