TRS-80 DOS – MultiDOS

Page Index

Background and History

It all started with SuperBASIC …

SuperBASIC was a re-modified version of Microsoft’s BASIC as modified by Apparat (NEWDOS). SuperBASIC started with version 3.0 because Microsoft’s BASIC for TRSDOS was at version 2.1. SuperBASIC 3.0 used ROM calls that were not in Microsoft’s version (despite the fact that Microsoft wrote the ROM); and, had ALL new code for the 28 Disk BASIC links. In addition, Vernon added CMD”O” – open an additional file buffer area keeping variables intact (this was dropped in MULTIDOS), CMD”X” – transfer the resident BASIC program to LEVEL II (this was later changed to CMD”W” in MULTIDOS), BASIC program chaining (NAME for Model I/III and CHAIN for MAX-80/Model 4), and a much faster CMD “doscommand” (no checksum was performed because SuperBASIC updated TOPMEM [4049H]). {by the way, Apparat STILL did not update TOPMEM with NEWDOS80/2}. Vernon just gave away SuperBASIC 3.0 for free and the owner of Level IV Products, Chuck (Virgil) Cheseldine, heard about SuperBASIC. Chuck and Vernon talked (about May 1980) and he suggested that Level IV Products should sell SuperBASIC 3.0.

… but what Operating System will run it? ULTRADOS …

At that time TRSDOS was up to version 2.3, NEWDOS/80 for the Model I was coming; and, to ensure Chuck and Vernon had a ‘foundation’ to sell SuperBASIC, Chuck suggested that Vernon make a DOS. Yikes!! The initial name was Level IV DOS, and Vernon did the same thing Apparat did in acknowledging Randy Cook as the author of specific DOS modules (i.e., SYS0/SYS, SYS1/SYS, etc). Chuck had concerns about the Randy Cook acknowledgement. So, Vernon only slept for about 4 hours a night for a month redoing all of the /SYS modules. And, ULTRADOS 4.1 was introduced September 1980 in Chicago at a Computer Fair. Vernon cannot remember why the name was changed to ULTRADOS – and the 4 is just the Arabic version of ‘IV’. ULTRADOS was updated twice – October 1980 and March 1981. Vernon did not get a commission for ULTRADOS sales but did get promoted to Vice President.

… and let’s make that interoperable! MultiDOS …

Kim Watt (Berkley, MI) and Vernon started collaborating on new software ideas in early 1981. Chuck raised some concerns about that, so Vernon told Kim to forget it. Later Vernon regretted parting ways with Kim. Kim had this idea (in 1981!!) to created a method for spreadsheets, word processors, and database management software to be able to communicate among themselves (based on what Vernon can remember, Microsoft Office 95 finally did that). Vernon’s regret grew (into anger) over time and in April 1981, he gave up his Vice Presidency, and started a double-density version of ULTRADOS (ULTRA-II). The first ad hit 80-Micro in Autumn 1981 as ULTRA-II, and after subsequent discussions among people, Vernon changed the name to MULTIDOS as suggested by Charlie Butler (Alternate Source).

MULTIDOS is the only TRS 80 disk operating system (DOS) developed that uses a similar format in communicating among the TRS 80 MODEL I, MODEL III, MODEL 4, and the LOBO MAX-80, i.e., some machine language programs and most BASIC programs will run under MULTIDOS in all four machines. BASIC programs that contain PEEK, POKE, USR, CMD, CLOAD, and CSAVE will probably have to be changed.

MULTIDOS went on sale in 1981, and continued to be sold by Vernon until 1984 when Vernon became an author and AlphaBit Communications, Inc. (Dave Welsh) became the publisher. In 1987 Vernon upgraded MULTIDOS from version 2.0 to 3.0 extending the maximum system date from 1987 to 2043. AlphaBit informed Vernon that LS-DOS had a different date scheme and “requested” that Vernon use LD-DOS’s date scheme; therefore, MULTIDOS was (retro)grated, released 1 October 1987, to version 2.1 for the Model I, Model III, MAX-80, and Model 4. Similar to LS-DOS, MULTIDOS version 2.1 extended the maximum system date from 1987 to 2011.

AlphaBit sold MULTIDOS from 1984 through ???. Sometime in the early nineties, Computer News 80 informed Vernon that AlphaBit was telling people interested in MULTIDOS to forget the Model 4 and migrate to the IBM PC family of computers. Vernon permitted CN80 to sell MULTIDOS sometime in 1994. [CN80 was already publishing ASTROCAL since 1991. ASTROCAL was supplied on a combination DOS that booted in a Model I or Model III or Model 4.] CN80 was only interested in the Model 4 version; therefore, (being a little arrogant) Vernon sent CN80 Model 4 MULTIDOS version 3.0 (date to 2043). Any upgrades to the Model I and Model III versions of MULTIDOS were strictly ‘internal’ i.e., just Vernon.

… and let’s free up more RAM! ESOTERIC.

In June 1998 Vernon decided he wanted to take advantage of a different Model 4 memory map which would afford 2048 more free bytes for applications, so he developed ESOTERIC.

OK … but did Vernon make any other DOS’s?

Glad you asked! In November of 1982, Vernon also wrote Z’DOS which was simply an attempt to get people into something other than TRSDOS at a reasonable cost. Z’DOS was never updated and three versions were created: Model I Single-Density, Model I Double-Density, and Model III.

UltraDOS to MultiDOS Transition

DOS Feature Comparison Chart (January 1982)

MULTIDOS Version Number Scheme

MultiDOS was versioned numerically to 2 decimal places, which could then be followed by an uppercase letter, a lowercase letter, or both.

Uppercase Letters:

Lowercase Letters:

Lowercase letters simply meant a minor revision to the DOS (e.g., 1.6a, v1.6b, etc).

Both:

A version number of 1.6aS, would be major version 1.6, minor revision a, in Single Density.

Chronology

MULTIDOS Directory Records

Directory records are 32 bytes long in all DOSs except for Model III TRSDOS 1.3 (50 bytes). The differences between the directory records of MULTIDOS and LS-DOS are limited to bytes 0 – 2, and 16 – 19. The major difference between LS-DOS and MULTIDOS is the use of bytes to store the date and time. In LS-DOS the time is to the minute with a date range of 01/01/1980 through 12/31/2011. In MULTIDOS the time is to every other second (even) with a date range of 01/01/1980 through 12/31/2043.

The date format in LS-DOS kept the pre 1988 date format and used the bytes previously used by the access (user) password for the additional bytes required to extend the date to 12/31/2011 and the time to the minute.

The date format in MULTIDOS uses the pre 1988 date bytes for the access password, and uses the bytes previously used by the update and access passwords for the date and time.

Here is a summary of the date formats in the file primary directory entry:

ULTRADOS v4.1

Released:

• September 1980

Unique Features Include:

• Smart screen dump (circa 1980/1981)
• Multi-instruction AUTO commands
• Smaller BASIC footprints
• Ability to chain BASIC programs
• Lowercase driver automatically installed if hardware has lowercase modification.

BASIC innovations:

• “Shorter” BASICs
• CHAIN
• Space compression
• Dynamically open another file buffer area
• Transfer resident disk BASIC program to Level II BASIC
• LIST displays graphic characters
• Global editor
• “/” to list ‘BREAK in’ line.

SYSTEM innovations:

• CLEAR
• Screen dump graphics
• TOPMEM
• Automatic hardware recognition (lowercase modification)
• ATTRIB enables converting an invisible file to visible.

Download Link:

• According to Vernon Hester, author of UltraDOS, there are no existing copies of this DOS.

Contained the following files:

Contained the following library commands:

ULTRADOS v4.1 (Updated Version)

Released:

• October 1980 (still as v4.1)

Changes from v4.1 (above):

• Added GR/CMD to enable creation of all 63 graphic characters in BASIC
• Added VFU/CMD (Versatile File Utility) to provide three frequently disk operations: Multiple file copying, purging multiple files, and printing a diskette’s diretory in a format that would fit into a 5″ diskette jacket.

Contained the following files:

Contained the following library commands:

Advertisements:

ULTRADOS v4.2

Released:

• March 1981

Changes from v4.1 (above):

• Added BC/CMD: blinking cursor
• Added CO/CMD: drive configuration
• Added SPOOL/CMD: RAM SPOOLer
• Converted KN2/BAS and KNIFE/BAS into EDIT/SYS
• Added CMD”K” to zero an array
• Added CMD”L” to delete an array
• Added CMD”M” to move a program line
• Added CMD”N” to duplicate a program line
• Added CMD”Q” to sort (was the first BASIC to sort arrays)

Contained the following files:

Contained the following library commands:

Advertisements:

MultiDOS v1.0

Released:

• September 1, 1981 (Model I)
• January 31, 1982 (Model III)

Versions:

• Model I (Single-Density)
• Model III

Files:

• 24 (each dated September 1, 1981)

Beta Testers:

• Gordon Monnier, Kim Watt, and David Welsh

Innovations to BASIC:

• p[n] to list a page of lines
• C to CONTinue
• R to RUN
• CMD”V” to display scalar variables.

Download Links:

• Model I/MultiDOS v1.0
• Model III/MultiDOS v1.0

Background:

Originally called ULTRA-II an ‘internal’ DOS as the first name assigned to what became MULTIDOS. ULTRA-II was NEVER sold or given out to beta test.

Was released as a “new operating system by the author of ULTRADOS” and as the only DOS that can read (copy files from) all of the Model I and Model III operating systems. At the time “all” the Model I and Model III operating systems were: TRSDOS, NeWDOS, ULTRADOS, VTOS, DOSPLUS, DBLDOS, LDOS; and MULTIDOS.

Model I version had a “fatal bug” in DOS0/SYS discovered by Kim Watt.

The Model III version compared to the current released version of Model I except that the Model III version added DOS8 and DOS9 (DOS9 superseded HELP/CMD).

Contained the following files:

Contained the following library commands: [Red is Model III Only]

Advertisements:

MultiDOS v1.1

Released:

• January 15, 1982

Versions:

• Model I (Single-Density)

Files:

• 26 files, 12 of which still bear the v1.0 file date of September 1, 1981

Main Changes from v1.0:

• Fixed DOS0/SYS
• Added HELP/CMD
• Added SKIP/CMD

Beta Testers:

• Initial enhancements incorporated from feedback provided by: Johnn Audritsh, Charlie Butler, Mike Friedman, Andy Gariepy, Gordon Monnier, Kim Watt, and Paul Weiner.

Download Links:

• Model I/MultiDOS v1.1 (Note: Bears v1.0 Version Number)

Background:

Kim Watt discovered a “fatal bug” in DOS0/SYS, and since MULTIDOS v1.0 did not have a ZAP utility, Vernon had to send all his customers (about 10 at the time) a new diskette. Vernon did not advance the version number (so it still reads v1.0).

What was the bug? Well, there are five ways to interface to a dual-sided disk drive: [1] treat it as a two drives, [2] treat it as an 80 track drive. i.e., if the cylinder is above 39, subtract 40 and select side 1 (this is the way MAXIDOS interfaced with dual-sided drives), [3] treat it as a two-volume diskette (original way DOSPLUS interfaced to dual-sided drives). MULTIDOS/ESOTERIC still supports this scheme, [4] treat it as a one-volume diskette (original way LDOS interfaced to dual-sided drives). MULTIDOS/ESOTERIC supports this scheme, and [5] treat it as a one-volume with overflow.

The intent was to initially write to side zero and use side one only if side zero is full. This is the way DOS0/SYS was designed (incomplete at the time Vernon had to ship product). Vernon thought he had sufficiently ‘JRed’ around the ‘overflow code’ before Vernon shipped any – but he didn’t. Subsequently, Vernon abandoned the ‘overflow’ concept.

Contained the following files:

Contained the following library commands:

Advertisements:

MultiDOS v1.2

Released:

• February 28, 1982

Versions:

• Model I (Single, Double, and Pseudo)
• Model III

Download Links:

• Model I/MultiDOS v1.2S
• Model I/MultiDOS v1.2D
• Model I/MultiDOS v1.2P
• Model III/MultiDOS v1.2

Contained the following files:

Contained the following library commands:

MultiDOS v1.3

Released:

• April 23, 1982 (Model I)
• April 29, 1982 (Model III)

Versions:

• Model I (Single, Double, and Pseudo)
• Model III

Main Changes from v1.2:

• Added CONVERT/CMD
• Added PATCH/CMD

Banner:

• Model I on Track 0, Sector 1
• Model III on Track 0, Sector 4

Download Links:

• Model I/MultiDOS v1.3S
• Model I/MultiDOS v1.3D
• Model I/MultiDOS v1.3P
• Model III/MultiDOS v1.3

Contained the following files:

Contained the following library commands: [Red = Model III Only]

MultiDOS v1.4

Released:

• April 30, 1982

Versions:

• Model I (Single, Double, and Pseudo)
  (There was no Model III version)

Main Changes from v1.3:

• HELP/CMD became DOS9/SYS
• DOS6/SYS split into DOS6/SYS and DOS8/SYS
• Added EA/DOC
• Added CAT/CMD

DOS Banner Location:

• Single-density banner on track 16, sector 9
• Double-density banner on track 1, sector 1

Download Links:

• Model I/MultiDOS v1.4S
• Model I/MultiDOS v1.4D
• Model I/MultiDOS v1.4P

Background:

Released to allow the Model I version 1.4 to catch up with the Model III version 1.3 in having 40 Library commands.

Contained the following files:

Contained the following library commands:

MultiDOS v1.5

Released:

• May 15, 1982

Versions:

• Model I (Single, Double, Pseudo, and Kernel)

Main Changes from v1.4:

• Added DBLFIX/CMD
• Added ZAP/CMD
• Automatic recognition of Doublers

DOS Banner Location:

• Single-density banner on track 16, sector 9
• Double-density banner on track 0, sector 2

Download Links:

• Model I/MultiDOS v1.5S
• Model I/MultiDOS v1.5D
• Model I/MultiDOS v1.5P
• Model I/MultiDOS v1.5SK (Kernel for Computer Shack)

Contained the following files:

Contained the following library commands:

Advertisements:

MultiDOS v1.6

Released:

• September 25, 1982 (Model I)
• November 8, 1982 (Model III)

Versions:

• Model I (Single, Double, and Pseudo)
• Model III

Main Changes from v1.5:

• Format pattern selectable
• Added DDT/CMD
• Added TAPE/CMD
• Added automatic configuration for any doubler installed
• Merged TU/CMD into VFU/CMD
• v1.6b contained a minor change to BASIC/CMD
• v1.6.? updated CAT/CMD
• v1.6.? updated BASIC/CMD

DOS Banner Location:

• Model I banner track 0, sector 6
• Model III banner track 0, sector 4

Download Links:

• Model I/MultiDOS v1.6S / v1.6D / v1.6P
• Model I/MultiDOS v1.6aS / v1.6aD / v1.6aP
• Model I/MultiDOS v1.6b
• Model I/MultiDOS v1.6c
• Model I/MultiDOS v1.6d
• Model III/MultiDOS v1.6 / v1.6a / v1.6b / v1.6c / v1.6d

Contained the following files:

Contained the following library commands: [Red = Model III Only]

Advertisements:

MultiDOS v1.7

Released:

• December 6, 1983 (v1.7 for MAX-80)
• January 25, 1984 (v1.7b for MAX-80)
• May 1, 1984 (v1.7c for MAX-80)
• September 10, 1984 (v1.7d for MAX-80)
• September 15, 1984 (v1.7 for Model I)
• January 9, 1985 (Model 4)
• January 15, 1985 (v1.7a for Model 4)
• January 18, 1985 (v1.7e for MAX-80)
• September 15, 1984 (v1.7 for Model III)

Versions:

• Model I (Single, Double, and Pseudo)
  Single-Density was a 2-Disk Set
• Model III
• Model 4
• MAX-80

Main Changes from v1.6:

• Mainly merged DIR/SYS and DOS/SYS from v1.6 into INDEX
• Added drive control table for Model I and Model III.
• Removed FORMS code from resident DOS disappointing many customers.
• First version for the Model 4
• Model 4 v1.7a added PRT/CMD and SETCOM/CMD
• First version for the MAX-80
• MAX-80 version was rushed to ship, so 7 programs were not converted. MAX-80 v1.7b added CAT/CMD, DBLFIX/CMD, DDT/CMD, MEM/CMD, RS/CMD, VFU/CMD, and ZAP/CMD
• MAX-80 v1.7c split ‘Index’ into RESIDENT/SYS and DIR/SYS
• MAX-80 v1.7d added TA/CMD
• MAX-80 v1.7e added CDIR/CMD, FMAP/CMD, LO/CMD, MEMDISK/CMD, PRT/CMD, and SETCOM/CMD. Renamed RESIDENT/SYS to SYSRES/SYS and built in type-ahead

DOS Banner Location:

• v1.7D and v1.7 banner appeared on track 0, sector 2
• Model 4 banner appeared on track 0, sector 2
• MAX-80 v1.7 and v1.7b banners appear on track 0, sector 13
• MAX-80 v1.7c and v1.7d banners appear on track 0, sector 12
• MAX-80 v1.7e banner appears on track 0, sector 2

Download Links:

• Model I/MultiDOS v1.7S
• Model I/MultiDOS v1.7D
• Model I/MultiDOS v1.7P
• Model III/MultiDOS v1.7
• Model 4/MultiDOS v1.7
• MAX-80/MultiDOS v1.7

v1.7 for Model I Contained the following files:

v1.7 for Model III/4 Contained the following files:

v1.7a for the Model 4 contained the following ADDITIONAL files:

v1.7 for the MAX-80 contained the following files:

v1.7b for the MAX-80 contained the following ADDITIONAL files:

v1.7c for the MAX-80 contained the following ADDITIONAL files from 1.7b:

New Files:

Removed Files:

v1.7d for the MAX-80 contained the following ADDITIONAL files from 1.7c:

v1.7e for the MAX-80 contained the following ADDITIONAL files from 1.7d:

New Files:

Removed Files:

Contained the following library commands:

Model I Contained the following library commands:

Model III Contained the following library commands:

Model 4 and MAX-80 Contained the following library commands:

MultiDOS v1.71

Released:

• February 11, 1985
  March 4, 1985 (Model 4)

Versions:

• Model I (Single, Double, and Pseudo)
  [Single-Density was a 2-Disk Set]
• Model III
• Model 4
• MAX-80

Main Changes:

• Access NEWDOS/80 diskettes with GPL > 2
• Added CDIR/CMD
• Added FMAP/CMD
• Added LO/CMD
• Added MEMDISK/CMD
• Added PRT/CMD
• Added SETCOM/CMD

Download Links:

• Model I/MultiDOS v1.71S / v1.71D / v1.71P
• Model III/MultiDOS v1.71
• Model 4/MultiDOS v1.71
• MAX-80/MultiDOS v1.71

Model III Contained the following files:

Model III version contained the following library commands:

MultiDOS v1.72

Versions:

• Model III
• MAX-80

MultiDOS v2.0

Released:

• October 1, 1985
• January 1, 1986 (Model 4)

Versions:

• Model I (Single, Double, and Pseudo)
• Model III
• Model 4
• MAX-80

Main Changes:

• Included SKIP as a CONFIG parameter
• Ensure that GAT bytes CCH and CDH were per TRSDOS 6 documentation (not what TRSDOS 6 does)
• Added T4/CMD
• Added TWO/IDO
• Added SPOOL/CMD that can use expanded memory
• Added and SYSGEN/CMD
• Implemented side compare implemented
• Enhanced CMD”V” to display array values
• Enhanced SORT/BOL (MAX-80 & Model 4) to do multi-key/indirect sort
• Model 4 version allowed for hard drive support

Download Links:

• Model I: MultiDOS v2.0S / v2.0D / v2.0P
• Model III: MultiDOS v2.0
• Model 4: MultiDOS v2.0
• MAX-80: MultiDOS v2.0

Model I, III and 4 versions contained the following files (Red is for ONLY the models listed):

Max-80 version contained the following files:

v2.0 contained the following library commands:

MultiDOS v2.1

Released:

• October 1, 1987
• August 1, 1987 (Model 4)

Versions:

• Model I (Single, Double, and Pseudo)
• Model III
• Model 4
• MAX-80

Main Changes:

• Included a new date format to include time and extend maximum date to 12/31/2011
• GAT byte CBH now available for cylinder 203
• Added FIXDATE/CMD to change a disk’s date format
• Added SYSGEN/CMD to create various SYSRES/SYS configurations

Download Links:

• Model I: MultiDOS v2.1S / v2.1D / v2.1P
• Model III
• Model 4 (Double-Sided)

FIXDATE/CMD:

FIXDATE [:]d [(param[,ABS][,CHECK][,G])]<ENTER>
FIXDATE (H)<ENTER>

d = drive number — the drive number is mandatory.
param = 1) ZT converts 1.0 through 2.0 to 3.xx format (default parameter if none specified).
param = 2) TZ converts 3.xx to 1.0 through 2.0 format.
param = 3) OZ converts 2.1x to 1.0 through 2.0 format.
param = 4) ZO converts 1.0 through 2.0 to 2.1x format.
param = 5) OT converts 2.1x to 3.xx format.
param = 6) TO converts 3.xx to 2.1x format.
ABS or A = Specifies update files that are probably in the previous format to the new format.
CHECK or C=Display the files to be changed without changing them.
GAT or G = Update GAT bytes CCH and CDH to represent the number of physical cylinders less 35 in CCH, and the diskette’s configuration in CDH (see the discussion of these two bytes in the DIRECTORY STRUCTURE section).
H = Help.

FIXDATE/CMD changes the date format among the three formats used by MULTIDOS. It is recommended that you convert your disks once. It is relatively easy to convert your disks from 2.0 to the format used by 3.xx; however, the conversion from 2.1x to 3.xx or 3.xx to 2.1x may require the ABS parameter. The ABS parameter is used to convert files that their date format cannot be interpreted properly. Normally, during initial conversions, you would not use this parameter. However, it may be required if you are going to convert back to the 2.0 format with the TZ and/or REV parameter. Version 2.1x uses the bytes previously assigned to the access password to store the hour, minute, and year. The previous bytes for the date remained. Version 3.xx uses the bytes previously assigned to the update and access passwords to store the year, month, day, hour, minute, and seconds divided by two. The previous bytes used for the date are now used for the access password. ESOTERIC only uses the 3.xx format.

Although FIXDATE/CMD automatically updates the bytes on the GAT table at locations CCH and CDH (for use with Open/DOL on Version 2.11 or later) whenever any file’s date is converted, you may specify the G parameter to force this action if none of the dates are converted. Open/DOL, for versions 2.11 or later, has been changed to only access a diskette if the drive’s configuration agrees with the diskette’s configuration. i.e., if you put a single sided diskette in a drive that is configured double sided, Open/DOL does not open the file and returns “Drive Configuration Error.” (DOS error 40/28H). However, [V]FU/CMD has built in error messages and returns “Unknown error.”

FIXDATE/CMD will not change the dates on a floppy diskette in logical drive zero, and so the parameter :d was mandatory.

Contained the following files:

Contained the following library commands:

MultiDOS v2.11

Released:

• December 1, 1990

Versions:

• Model 4

Main Changes:

• Compensate for the ‘brain dead’ HD64180 microprocessor supplied with the XLR8er that alleged 8MHz processing for the TRS-80
• Added CP/CMD
• Added XCOPY/CMD
• Initial release of PCOPY (called XCOPY in 1990). Pcopy was written for a customer of Vernon’s who had a very large mailing list on his hard disk and wanted a backup in case his hard disk failed or he upgraded to another hard disk. Anyway, he pointed Vernon toward an application that DOSPLUS had, and Vernon created PCOPY. If you don’t have a hard drive, PCOPY is not much use. Let us say you want to backup a 300K file, and all you have handy is seven floppies with about 50K free on each. You can use PCOPY to backup your 300K file onto these seven floppies. And, you can restore any backup set. One must keep track on what set of floppies are in a given set because PCOPY will not let on mix floppies from different sets.

Contained the following files:

Contained the following library commands:

MultiDOS v3.00-v3.11

Released:

• April 1, 1987 (v3.00)
• December 1, 1996 (v3.01)
• March 1, 1997 (v3.10)
• March 1, 1998 (v3.11)

Note:

• Sold through Computer News 80 and contained special Computer News 80 utilities on the DOS disk.

MultiDOS v4.00

Official Build:

• November 8, 1998

Versions:

• Model I, III, and MAX-80

Notes:

• Never Released.

MultiDOS v4.01

Released:

• September 5, 1999

Versions:

• Model I (Single, Double, and Pseudo)
• Model III

Download Links:

• Model I / v4.01S / v4.01D / v4.01P
• Model III

MultiDOS v5.00

Official Build:

• December 15, 2002

Versions:

• Model 4

Main Changes:

• Implement major changes in the video routine.

Notes:

• Never Released.

MultiDOS v5.1

Official Build:

• August 1, 2004

Versions:

• Model 4

Notes:

• Never Released.

MultiDOS v5.11

Official Build:

• December 22, 2004 (and dated January 1, 2005)

Versions:

• Model 4

Contained the following files:

Contained the following library commands:

MultiDOS v5.00

Official Build: February 24, 2021

Versions: Model I and III

Main Changes: BASIC/CMD, BBASIC/CMD, RA/CMD, OPT/BOL, and UTIL/BOL were updated. CAT/CMD and Open/DOL were zapped.

Download Links:

• Model I: SSSD / SSDD / DSDD
• Model III: Single Sided / Double Sided
• Updated Manual in DOC Format

MultiDOS v5.10

Official Build: October 12, 2023

Versions: Model I and III

Download Links:

• Model I MultiDOS v5.10 in Double Sided Double Density Format.
• Model I MultiDOS v5.10 in Single Sided Double Density Format.
• Model I MultiDOS v5.10 in Single Sided Single Density Format.
• Model I MultiDOS v5.10 for the FreHD.
• Model III MultiDOS v5.10 in Double Sided Format.
• Model III MultiDOS v5.10 in Single Sided Format.
• Model III MultiDOS v5.10 for the FreHD.
• MultiDOS v5.1 and Esoteric v3.2 Manual (DOCx Format).

Main Changes:

MultiDOS v6.00

Official Build: February 24, 2021

Version: Model 4

Main Changes: BASIC/CMD, Library3/EXT, MEMDISK/CMD, MODULE/CMD, MONITOR/CMD, RA/CMD, SORT/BOL, UTIL/BOL were all changed.

Download Links:

• Single Sided / Double Sided 80 Track / Double Sided 40 Track
• High Resolution Program Disk for MultiDOS v6.00
• Updated Manual in DOC Format

MultiDOS v6.20

Official Build: October 14, 2023

Versions: Model 4

Download Links:

• Model 4 MultiDOS v6.20 in Double Sided Format.
• Model 4 MultiDOS v6.20 in Emulator Format (too big to fit on a real floppy).
• Model 4 MultiDOS v6.20 in Single Sided Format.
• Model 4 MultiDOS v6.20/Esoteric v3.20 for the FreHD.
• MultiDOS v6.2 and Esoteric v3.2 Manual (DOCx Format).

Main Changes:

Z’DOS

Released:

• September 30, 1982 (Model I/Single Density)
• November 19, 1982 (Model I/Double Density)
• November 20, 1982 (Model III)

Versions:

• Model I (Single and Double)
• Model III

Download Links:

• Model I/Single Density
• Model I/Double Density
• Model III

Background:

Vernon wrote and released Z’DOS as an attempt to get people into something other than TRSDOS at a reasonable cost. Z’DOS v1.0 was never updated.

Contained the following files:

Contained the following library commands:

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Esoteric

Released:

• July 11, 1998 (Preliminary)
• December 13, 1998 (v1.0)
• November 25, 1999 (v1.1)
• January 1, 2001 (v1.2)
• August 12, 2002 (v2.0)
• August 1, 2004 (v2.1)
• November 29, 2004 (v2.11)

Version:

• Model 4

Download Link:

• v2.11 for the Model 4

Background:

ESOTERIC is essentially Model 4 MULTIDOS using the Model 4’s Memory Maps III and IV. MULTIDOS uses Memory Map II. The only benefit (if any) of Model 4 MULTIDOS over ESOTERIC is that Model 4 MULTIDOS can operate in both the 64×16 screen and the 80×24 screen, whereas ESOTERIC is only a 80×24 screen system.

In a March 1983 San Francisco computer show, LOBO came to Vernon’s booth and they talked about the MAX-80. In April 1983 a MAX-80 arrived in Vernon’s office and he began to convert Model I DOS to work in the MAX-80. The MAX-80 was capable of either 64×16 or 80×24 video. Vernon cobbled a version of BASIC using fragments of the Model I ROM and his Model I/III disk BASIC. The primary purpose of the dual video was to enable an easy transition of Model I/III BASIC programs to a faster machine (5.06667 MHz) without having to rewrite display code. And, the 80×24 screen could be used for new developments and/or converted 64×16 stuff. Programs such as “Android Nim” execute flawlessly in Model 4 MULTIDOS – provided, of course, that one is in the 64×16 video mode.

Vernon did not want to do a Model 4 MULTIDOS; however, many customers wanted the ‘easier’ transition to a 4MHz/80×24 capable machine. Therefore, Vernon converted his MAX-80 version of MULTIDOS to the Model 4. To be clear, first came the MAX-80 MULTIDOS, and second came the Model 4 version of MULTIDOS. ESOTERIC would have been the Model 4 version of MULTIDOS if Vernon had planned on competing with TRSDOS 6 in either late 1983 and/or early 1984. MAX-80 MULTIDOS hit the streets in September 1983, and Model 4 MULTIDOS was not released until February 1985 – customers were begging. One of the ‘easier’ transitions the Model 4 MULTIDOS provided is the exact matching of 115 of 124 keywords (the nine mismatches are minor).

Vernon created ESOTERIC in June 1998 (as he had nothing else to do with his Model 4) to gain the 2048 bytes consumed by the permanent address space used for the keyboard and video in Memory Map II. The primary difference between ESOTERIC and Model 4 MULTIDOS is the video (80×24 vs. either 80×24 or 64×16) and ESOTERIC is mapped significantly different than Model 4 MULTIDOS. The mapping of the Model 4 is very similar to the Model I, Model III, and MAX-80 version of MULTIDOS. ESOTERIC’s mapping difference was desired to keep the DOS in contiguous memory (0000H through 1AFFH). Under ESOTERIC, one can ORG applications at 1B00H.

Contained the following files on the DOS Disk:

Contained the following files on the UTILITIES Disk:

Contained the following library commands:

Esoteric v2.12

Released:

• July 11, 2011 (v2.12)

Version:

• Model 4

Download Links:

• v2.12 for the Model 4
• v2.12 w/High-Res BASIC for the Model 4

Contained the following files on the DOS disk:

Contained the following files on the UTILITIES disk:

Contained the following library commands:

Esoteric v3.00

Released: February 23, 2021

Version: Model 4

Main Changes: Updated BASIC/CMD, Library3/EXT, MEMDISK/CMD, MODULE/CMD, MONITOR/CMD, RA/CMD, SORT/BOL and UTIL/BOL.

Download Links:

• Single Sided / Double Sided 40 Track / Double Sided 80 Track
• High Resolution Program Disk for Esoteric v3.00
• Updated Manual in DOC Format

Esoteric v3.20

Official Build: October 14, 2023

Versions: Model 4

Download Links:

• Model 4 Esoteric DOS v3.20 in Single Sided Format.
• Model 4 Esoteric DOS v3.20 in Emulator Format (too big to fit on a real floppy).
• Model 4 Esoteric DOS v3.20 in Single Sided Format.
• MultiDOS v5.1 and Esoteric v3.2 Manual (DOCx Format).

Main Changes:

Q & A With Vernon Hester

Given the evolution of the PC industry, in hindsight, what evolutionary steps could the TRS-80 (Z-80) have taken to maintained their dominance (this includes Z80 improvements, hardware, software, etc)

The 8-bit (16-bit addressing) microprocessors (8080, 6800, 6502, and Z80) can address only 64K of memory. An improvement to some of the 16-bit addressing families is a memory management unit (MMU) that enabled addressing up to 1M of memory (notably the HD64180/Z180). Although there usage could have extended the life of the TRS-80, software to effectively use this capability was non-existent. And, with the advent of microprocessors (Intel 8086) with 20-bit addressing (1M of memory) in 1978, computers with a limit of 64K were doomed; however, the Commodore 64 maintained a major market share through 1989 (Ref: Wikipedia)

The Model III, released in 1980, should have had twice the memory capacity and twice the CPU speed compared to the Model I that was released in 1978; and, the Model 4, released in 1983, should have had eight time the memory capacity and four times the CPU speed compared to the Model III. Perhaps, the Zilog development of the Z80 family hampered the TRS80 going to 14 MHz.

Here’s a simple chart of my “hindsight” on what the TRS-80 should have been:

NOTE: Radio Shack peripherals never included a print SPOOLer. Hardware SPOOLers could have easily achieved four Megabytes by the end of 1984. I imagine a hardware SPOOLer requires a minimum of engineering; and, with no moving parts, would have an infinite life in the TRS-80 world.

The HD64180 microprocessor, released in 1985, should have been the chip used in the planned Model 5 instead of the Z800 that never came to be. By the way, the Z800 morphed into the Z280 in 1987 that bombed.

Dream System:

• The Model 5, released 1986 (based on the ‘hindsight’ evolution)
• HD64180/Z180 microprocessor with 1 megabyte of memory.
• Add six keys: Delete, Home, End, Insert, Page up, and Page down.
• New OS could extend file dating to 2107.

Radio Shack announces development of the Model 5 and urges all major software houses to start writing code for the new Z180 microprocessor. Radio Shack sells prototype machines to software developers on a first come first served basis for only the shipping and handling cost.

Summary:

• Faster microprocessors
• Full ASCII keyboard (minor – but an inconvenience)
• More Memory – at least 256K
• Give software developers a heads up on hardware modifications/upgrades

I have a perception that Radio Shack was simply arrogant when it came to the Model III and Model 4 and probably never heard of Moore’s law.

Radio Shack Model III apparent “errors”:

Model III TRSDOS developed by Radio Shack, albeit better than the initial release of the Model I DOS, was not media-storage compatible with Model I TRSDOS. All of the alternate DOSes had media-storage compatibility between the Model I and Model III. (The significant limitations and errors with Model I TRSDOS, created an opening for alternative DOSes to emerge.)

The Model III was designed to run at a microprocessor speed of ~2.03 MHz. Why only 2 MHz? The Model II released in 1979 was running at 4 MHz. Speed up kits enabled one to run the Model III at 5.07 MHz. Peter Ray (Anitek) designed a Model 4 speed up that ran the Microprocessor at (6.7/6.1/5.1) MHz and 2.03 MHz. Why couldn’t Radio Shack do ~4/2MHz. Oh, that’s the Model 4! The Model III boasted 14K ROM. For another 2K we got lowercase, faster cassette, and TIME$ – gee golly wow!

In addition, Radio Shack managed to screw up the new ROMs. Notably are the behavior in the 32 characters/line mode (0348H), the “safe” exit to basic via a JP 0072H (some people bypassed this and used 06CCH), the code to return the printer status at 05D1H, and the code at 02C3H – this was subsequently fixed because the Model III would go out to lunch if the key is pressed after keying SYSTEM. Is it because Radio Shack “explained” the behavior they did not have to fix the code?

My conclusion: The Model III should have been more than the Model 4.

Radio Shack Model 4 apparent “errors”:

The Model 4 still did not have a full ASCII keyboard. There is simply no excuse for this decision. LDOS is a decent DOS; however, many people dropped the TRS-80 line in 1983/1984 because of LDOS. Furthermore, Radio Shack and Logical Systems could not agree on a solution (cost) for the 1987 date limit in TRSDOS 6.x. Imagine if DOSPLUS, NEWDOS80, and MULTIDOS were still competing with LDOS. The date extension cost would have been zero!

My conclusion: The Model 4 is not much more than a souped-up Model I.

Overall:

With the boon years (1979-1982), Radio Shack could have created/managed a user group (ref: Heathkit) that would have provided a wealth of useful information. Of course, Radio Shack did not have to implement any of the user group’s ideas; however, Radio Shack would have had a much better idea where the industry was headed. Nevertheless, the 16-bit microprocessors trumped the 8-bit microprocessors about 1984. Zilog finally developed eZ80 in 2001. The eZ80 is an 8-bit microprocessor with 24-bit addressing: 16M linearly.

Too little too late: With VisiCalc available for the Apple II in 1979, the Apple II started outselling the TRS-80 by 1982. Radio Shack discouraged third party software developers and planned to develop all software internally or have external software developers design their software so it would only work with TRSDOS. Although VisiCalc was available for the TRS-80 in 1980 (that is too long after the Apple II), it was designed to work only with TRSDOS.

Finally, in 1985 Radio Shack sold the Model 4D with DeskMate (“D” for DeskMate). DeskMate had four useful and integrated functions – Database, word processor, spreadsheet, and a calendar. Kim Watt had that idea back in 1980!

What are some examples of your favorite Z-80 assembly “tricks” or techniques that you think fellow codes might appreciate.

Techniques

Know what and how instructions affect flags – especially the P/V flag. Flags don’t change randomly. i.e.,

• LD A,(HL)
• OR A
• JR NZ,dog
• OR A; you get here only if the zero flag is set

… is just as bad as …

• XOR A

Use all four flags (Sign, Zero, P/V, and Carry) – I’ve seen code where there is a tendency to use the sign flag when the carry flag will do. A possible advantage of the carry flag is a conditional branch can use a jump relative (JR) instruction instead of a jump (JP) instruction. The JR instruction is only two bytes whereas the JP requires three. And, depending on the circumstances, the JR “may” be faster.

Involve the entire instruction set. i.e., don’t hold back so that the code may be used in an 8080 environment.

Don’t write ROMable code. Whoever ROMed their code?

Where possible use the DJNZ instruction vs DEC D, DEC E, or DEC C, etc.

Use conditional calls where possible.

Use a “MONITOR” to debug and/or enhance code. The use of a monitor can possibly enable you to detect redundant code and possible “masking”. i.e.,

This segment is 13 bytes.

“masking” enables you to reduce by one byte. And, saves two “t” states if DE is 0.

The “masking” values HL with some arbitrary value. This is not a problem because the HL register pair is valued with the contents of LION with the next instruction.

What are your thoughts on the evolution of microprocessors and how current OS’s take advantage of their capabilities?

This is a question I am not qualified to answer. However, I do have an opinion. Microprocessor development in the 1980’s evolved to the point where they can completely replace code to perform algebraic addition, multiplication, division, trigonometric functions, square roots, logarithmic, and exponentiation in both single-precision and double-precision. Now they can perform string compare. This has enabled OS’s and applications to develop only the high-level algorithms and not bother with the primitive functions. Resulting in faster development of new applications.

Would you ever release your source code to the public domain so that others could learn from your code?

Yes.