MAX DOS: A Study of DUAL DOS in the TS-2068

For several weeks UPDATE has been testing TWO SIMULTANEOUS Disk operating systems in the TS-2068. This is the Oliger SAFE DOS and the Larken DOS. The hardware hook-up is the FULL “two board” Oliger system and the Larken LKDOS cartridge in the Dock Port. Extensive operation with the combination has revealed an almost complete compatability between the two systems. The only incompatabilities are minor and will be discussed. For the the test two disk drives were used, but a single drive could have been used as well. Drive zero had a disk formatted as a Larken Disk, and drive 1 had a disk formatted as a Oliger disk.

In the beginning the Oliger V2-40 EPROM was being used. Actually the instructions provided with the Larken LKDOS cartridge calls for the removal of the Oliger “board A” which contains the SAFE EPROM. But I’m adventurous and I decided to keep both Oliger boards in and see what would happen. The system seemed to work O.K. Both the Oliger DOS and the Larken DOS operated normally. After about a week of operation I kinda got used to having DOUBLE the amount of EXTRA BASIC functions. All of the Oliger functions worked and so did all of the Larken functions. AND, it did not make any difference which DISK was used for actual SAVE and LOAD. In fact, ALL of the SYNTAX structure for BOTH systems can be used in program lines, or can be used in the direct mode. We will explore this a bit.

Oliger SAFE commands use the slant bar “/” as a designator. Example: “SAVE/ “title”. The Larken commands use <PRINT# 4: SAVE “Title.B1”>. The disk in use is selected by <LET/d=0> or <PRINT# 4: GO TO 1>. Now suppose a program line were: <100 SAVE/”file 1″DATA a$(): PRINT #4: SAVE “file 1.a$”DATA $()>. The TS-2068 accepts the syntax and the line enters OK. When the line executes, the first command results in the disk “automatically switching” to the Oliger disk and the data file is SAVED to the Oliger disk. Next, the Larken syntax results in an automatic switch to the Larken disk, and a SAVE of the same data file to the Larken disk. Both systems “remember” its own disk as elected by <LET/d=> for Oliger, and <PRINT#4:GO TO> for Larken.

Likewise, all other disk commands and all Extra Basic commands operate exactly as they would normally. The nice part is that all of these functions are additive, and operational as ONE BIG DOS. The Oliger FAST FOR counter works with LARKEN programs. The Larken Window functions work with a Oliger program. In fact, a program loses its idenity as a Oliger program or a Larken program. It can be saved or loaded in either disk format. One can coose which simply by using one DOS SAVE or LOAD command, or the other. Now, if I receive a disk from someone, I can load it if it is in either format. One can operate entirely with one disk format if he chooses, AND use All of the extra basic functions of BOTH Larken and Oliger systems. But there are strong advantages of using two disk formats.

Each of the two systems commands the Disk Drive through the Western Digital controller chip. There are certain Files Management functions which are more versatile when using the Oliger format, and others that give more capability when using the Larken Format. So the use of two diskettes does provide more options of disk files management. In effect, “MAX DOS” is controlling double the amount of disk storage- two diskettes under automatic controll. Now “MAX DOS” is my own coinage. I wanted something that would denote a BIG Disk Operating System, as opposed to “a choice of one or the other”. Besides, I always like to twit the IBM users. Their “MS DOS” sounds like a “mess”, while “MAX DOS” sounds like the “mostest”.

Compatability with Existing Hardware: Both Oliger DOS and Larken DOS are compatable with the Spectrum ROM Switch. Both are compatable with the Zebra OS-64, but the LKDOS Cartridge takes up the Dock Port. The Larken literature discribes an additional IC that can be piggy-backed to accept either the OS-64 EPROM or the Spectrum ROM IC. UPDATE has not tested this modification. The SPDOS software on-Disk is compatable with both Larken and Oliger systems. The loading of SPDOS would give a third FORMAT and enable the use of RAMEX disk programs.

COMPATABILITY of EPROMS: UP-DATE received the new Oliger V2-52 EPROM and the system crashed when the LK cartridge was installed. A call was made to John Oliger who seemed confident that the conflict was caused by “two different brands” of EPROM used by the two systems. Apparantly the EPROM that has the “penthouse” on top cannot be used with the Larken Cartridge. I sent an old “flat top” EPROM to John for re-programming. When it was returned, the compatability was restored. Since then, all of this magazine issue pages have been prepared and printed with BOTH DOS systems installed. One non-compatability exists. Both Larken and Oliger systems have NMI functions. These functions clash and the NMI button cannot be used. To date, this is the only conflict found.

Conclusions: MAX DOS is a reliable combination of two very capable disk operating systems, and two excellent Tool Kit extensions of the Basic language. This combination operates as if the two systems had been designed as one large system. The tool kit extensions are not just Basic Commands, but are groups of functional routines. MAX DOS provides as many disk management functions as any DOS used by any computer. The extra tool kit functions greatly extends the job tasks that the computer can perform. These new functions are many and are unique. No other computer has them in their repertoire of functions. Some of the notable attributes of MAX DOS are listed below. Then a sample bit of programming will be given to conclude the report.

1. Disks prepared by either Larken DOS or Oliger DOS can be read by MAX DOS.

2. Disks may be prepared for use by others who have single Larken DOS or Oliger DOS.

3. The plethora of Extra Basic Tool Kit functions of Oliger DOS and Larken DOS are combined.

4. The Larken and Oliger Command Syntax for both Disk operation and Tool Kit Basic may be mixed in programming.

5. The system exercises direct conrol of two disk drives simultaneously. Switching is automatic.

6. The system makes use of the excellent Oliger printer driver in EPROM. No need to load another printer driver.

7. No RAM memory is used by either Oliger or Larken DOS, thus MAX DOS does not use any RAM.

8. The TS-2040 printer is directly supported, simultaneously with a Centronics printer, or separately.

9. Direct low res Screen Copy is available by simple command.

10. No conflict with Spectrum ROM, or any Extra Memory device.

9000 BORDER 1: PAPER 1: INK 7: CLS : LET /p=o: RANDOMIZE USR 100: OPEN #4,"dd"
9030 PRINT AT 10,0;"Install Formatted disks in:"''"Oliger Format in Drive 0"''"Larken Format in Drive 1"'''"Enter When Ready": PAUSE 0: CLS
9040 PRINT AT 10,0;"SELECT:"''"<1> To Move Screens TO LARKEN DISK"''"<2> To Move Screens TO OLIGER DISK": INPUT b: IF b<1 OR b>2 THEN GO TO 9040
9050 PRINT AT 10,0;"Which way to Move?"''"<1> Oliger to Larken"''"<2> Larken to Oliger": INPUT c: IF c<1 OR c>2 THEN GO TO 9050
9060 CLS : PRINT AT 10,0;"Install Disk in Drives"''"Then ENTER": PAUSE 0: CLS
9070 INPUT "Number of Screen files to move? ";m
9080 FOR n=1 TO m
9085 IF b=1 THEN LET /d=0: CAT : INPUT "Screen file Name?";a$: LOAD /a$SCREEN$ : LET a$=a$+".C1": PRINT #4: GO TO 1: PRINT #4: SAVE a$SCREEN$ : NEXT n
9090 IF b=2 THEN PRINT #4: GO TO 1: PRINT #4: CAT "",: INPUT "Screen file Name?";a$: PRINT #4: LOAD a$SCREEN$ : LET /d=0: SAVE /a$SCREEN$ : NEXT n
9100 STOP