An evaluation of Snapp-Ware's enhancements to LDOS

Models l/lll, PMC-80, LNW80

Okay, you LBASIC users! Tired of seeing the DOSPLIJS, NEWDOS/8o and MULTIDOS users doing all those neat things from BASIC that LBASIC doesn't provide? One might view LDOS LBASIC as a little lean in BASIC features and BASIC utilities compared to these other DOSs. LBASIC does have quite a few really nice features that are missing from standard TRS-80 Microsoft BASIC and some features that no other DOS BASIC has, but I do miss having some of the more advanced programmer utilities from within LBASIC. Well, Snapp-Ware has just released something LDOS BASIC users will definitely appreciate.

I had been reading about Snapp Extensions for the Model II for quite a while. Snapp has now released their extension packages for Model III TRSDOS 1.3 and Model l/lll LDOS. There has also been added a new extension called "reverse compression" since the first TRSDOS 1.3 release. This review will deal with the new LDOS Snapp package, but it does relate to the TRSDOS version, except for price differences.

There are six packages advertised, consisting of:

Extended BASIC $39.50

Built-in Functions $34.50

Screen Mapping Support... $34.50

File Mapping Support 29.50

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Garbage Collector $34.50

Reverse Compression $19.50

There is also an LDOS trial demo disk for $10. It allows you to make one working Snapp LDOS disk to use and see which, if any, of the extensions you want to buy. This is a great option. The buyer can see 52 80-U.S, Journal exactly what these packages offer. These packages are not cheap, and if you bought all six, they would cost close to $200.

Upon receiving my LSNAPP (LDOS Snapp Extensions) package, I found it included a seventy-six-page manual and one floppy disk. The manual is well written, with a table of contents pointing you to the features of Snapp extensions. Each extension has its own section in the manual with clear instructions and examples. In the back of the manual are a few real-world programs. Like all other computer program manuals, it could use more examples.

Before you can use the new package, you have to install it on an LDOS system disk. After Snapp extensions are installed, you can put any programs or files you want on the disk. The installation procedure is quick and easy. I was a little surprised, because I thought it would be more involved. There is a PATCH file that you use to patch LBASIC, which takes all of about ten seconds.

The next part of the installation creates a file named SNAPPINC on the LDOS disk. This file consists of the Snapp library commands and takes four cylinders of disk space. This is the only part of the installation procedure that takes preplanning. You must preplan the starting cylinder that the file SNAPPINC will start on.

This is easily done with the LDOS FREE map command. You simply find four empty cylinders, starting as close to the directory cylinder as possible. These four cylinders should also be in a contiguous, unbroken format. Placing the SNAPPINC file as close to the directory as possible is done for

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efficiency. Some Snapp routines are pulled into LBASIC, as they are needed, similar to the way the DOS system uses overlays. This saves valuable computer memory by loading just the code that is needed for a certain function. If the routines (SNAPPINC file) are located too far from the directory and broken up into extents, this will slow the speed of LBASIC considerably because of inefficient disk read —head movement.

After I purged my unwanted files from my LDOS disk, the FREE:0 command showed plenty of room starting at cylinder 27. All we do now is enter the starting cylinder and press ENTER. You can make backups from Snapp LDOS, but you will have to initialize the backup with the Snapp distribution master before it will run correctly. The master distribution disk cannot be copied, so it would be a good idea to make a few run-time LSNAPP disks. This way, if the master distribution disk is damaged, you will still have some LSNAPP disks to use while you send back the distribution master for replacement.

Extended Built-in Functions

I loaded LBASIC and started trying the extended built-in functions package. This thing was more powerful than I had first thought. It had some great POKE and PEEK extensions. With normal BASIC, you can POKE or PEEK into RAM only one byte at a time. Now, I had commands like PEKW, that would read two bytes (word) from memory, and PEK$, that would extract any number of bytes from RAM, up to a length of 255.

I looked in the manual for the POKE command. You could POKE a string of characters up to 255 bytes

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