Node DATAPAC/RAMDisk Review Copyright 1987 by Tom Fitzpatrick The Product DATAPAC 128K or 256K RAM expansions with RAMDisk ROM software, for Model 100/102/200 computers. This review was written using a M100 with the 256K RAM and v.1.05 of the RAMDisk software. Available for $249 (256K) or $179 (128K) from: Node Systems, Inc. 408 Broad Street Nevada City, CA 95959 (916) 265-4668 What you get The DATAPAC is a wedge-shaped anodized aluminum box approximately 10" long by 1 7/8" wide by 1" tall. It attaches to the Model 100 with provided Velcro strips and a cable that connects to the system bus. Once connected, the device raises the M100 up to a nice viewing angle and eliminates the need for "legs." The entire package just barely fits into the M100 case if the closing flap is left open. RAMDisk software comes on a ROM and thus avoids high memory conflicts with machine language programs. Instructions come in two forms; installation, menu-driven operation and trouble-shooting information come on three pages (front and back). These instructions are brief and to the point. Page 3 should look familiar; it is a reproduction of page 8 of the Model 100 owner's manual! Instructions for using the Datapac in Basic are included on the ROM. This is done in an interesting way. When the Datapac is first set up, an 11K file is placed on the RAMDisk menu called, appropriately enough, RAMDSK.DO. This file can be edited or printed like any other Document file and can be reduced to an empty file. If the file is killed, it is automatically restored to its original 11K size. The Good. . . This device adds 256K to an existing 32K Model 100 for a total of 290K. This 256K of memory is made available through the use of an alternate file menu. When the RAMDisk software is activated, files are displayed in a format similar to the main menu. The first display line shows the date and time, followed by the TEXT ROM program, BAsic, DOcument and COmmand files on lines two through seven. Line eight shows function key definitions: EXIT, NAME, PAGE, COPY and KILL. In addition to providing a file menu, the RAMDisk software also makes enhancements to TEXT. Search-and-replace, length and word count, and a toggle between text overwrite and text insert are all available with control keys L, J and O, respectively. The Bad. . . "Contiguous RAM" is an ambiguous term where the Model 100 is concerned. The reason appears to be a limit of the Model 100 central processing unit--the 80C85--itself. It can address only 64K at a time. Datapac designers found an unusual way to circumvent this problem. Files are run or edited only in the main 32K, not in the Datapac. In the case of a Text file, RAMDisk software moves the file from the Datapac to main RAM, allows you to edit the file, then moves it back to the Datapac. The entire process is invisible to the user. This procedure limits the Datapac's use. If no other programs exist in the main 32K of memory, the largest file that can be created is 29500 bytes long. If a 2500 byte text formatter is kept in the main RAM, the size of the largest Datapac file accessible decreases to only 27000 bytes. The benefit of having a Datapac is that anywhere from eight 29500 byte files to over 200 1K files (256K model) can be maintained at one time without a disk or tape drive. Using Basic or Command programs isn't quite as easy as Text files. Running a program is accomplished by either selecting it from the RAMDisk menu or copying it to the main 32K. Programs selected from the RAMDisk menu are copied into the main RAM as part of another program, executed, then left in the main 32K. If copied to the main 32K, a program can be run as usual from the main menu. For instance, to run a 2500 byte Basic formatter from the Datapac, one would select it from the RAMDisk menu, it would execute, then would remain in and continue to take up 2500 bytes of main memory. Using the latter method, the program would be copied into the main RAM and run. The program could be killed from Basic when through. A method is offered to simplify the process, but it involves editing each and every Basic program and substituting {MENU for MENU. Also inconvenient is the matter of file size. The Datapac saves files in 1K blocks, so ten 512 byte files that would require 5K in the M100 would occupy a full 10K in the Datapac. The Ugly. . . Problems found with the product involve the RAMDisk software and documentation. The first software problem is bug. If one tries to copy a RAM file to the Datapac and types RAM:FILENAME instead of FILENAME, the software thinks it is displaying the Datapac files when in fact it is listing the main RAM instead. No damage is done, but can prove confusing. The RAMDisk software has what might be called "function key ease," but it isn't completely user-friendly. Should one do something the software dislikes, it beeps but provides no error message or indication of what was done incorrectly. Copying files from the Datapac to the main 32K and back is fairly simple, but requires the filename to be typed in each time. To copy from the Datapac to main RAM requires typing RAM:FILENAME. An undocumented feature is that you DO NOT have to type a file's extension. (For example, to copy RAMDSK.DO from the Datapac to the main RAM you only need type RAM:RAMDSK, not RAM:RAMDSK.DO.) Placing instructions for Basic access on ROM might come in handy, but the least the folks over at Polar Engineering (who apparently wrote the RAMDisk software and instructions) could do was proofread them and run the file through a spelling checker first! Information on the Problems/Hints page appears to be inaccurate in regards to the corruption of a small program that invokes the RAMDisk software. If this program is corrupted or deleted, all one need do is type KILL"RAMDSK and press ENTER. A quick CALL 63013,1 from Basic restores the program. Removing the Datapac and turning off the memory power switch is NOT necessary unless the computer locks up and cannot be recovered with CTRL-PAUSE-RESET. Hardware for the Model 100 Datapac is a modified Tandy 102 version. The cable connecting it to the system bus isn't lined up correctly, leaving a small twist in an otherwise neat installation. Most unsettling were installation instructions that read, "The cover of the ROM expansion compartment may optionally be reinstalled ... a small 2" wide notch may be cut on the cover to facilitate cable entrance into the compartment." Why couldn't Node have just provided a thirty cent piece of plastic to save buyers the inconvenience?!? Finally, because the unit monopolizes both the system bus and the option ROM socket it prevents use of the DV/I, Chipmunk disk drive and ROM software. The Tandy portable disk drives can be used, as can third party disk operating systems not on ROM. To sum up Contiguous RAM is easier to use than the banked RAM products offered by other companies, and the price of Node's product is about half of the competitors. Because the unit functions as a solid-state disk drive instead of banked RAM, cold starts in the Datapac are non-existent. (The Datapac can be "formatted," but this requires a CALL 63013,9 from Basic) Should a cold start happen in the Model 100, information in the Datapac is left untouched. The best feature of the device is what it eliminates--the need for a disk or tape drive when traveling. I've found 256K holds most of my utility programs, a text formatter and an Xmodem telecommunications program with more than enough room left over for text files written on the road. Although not perfect, the Node Datapac is worth owning. Suggestions Worthy improvements that could be made include Terminal enhancements for downloading to the Datapac, a Tandy portable disk drive operating system and a Datapac-to-disk backup utility on the ROM with the RAMDisk software. All these are available now in public domain or commercial software, but it would be much more convenient to have them on ROM. Unfortunately, the people at Node say a ROM update is not likely in the near future.