86-DOS 0.10
| Version of 86-DOS | |
 | |
| Version | 0.10 |
|---|---|
| Compiled | 1980-07 |
| Replaced by | |
| 86-DOS 0.11 | |
86-DOS 0.10 is the first beta[1] build of QDOS/86-DOS. It was in a roughly half-complete state when compiled.[2] An estimate of only 10 people have ever seen it,[1] and it was never shipped.[3]
Features[edit | edit source]
86-DOS 0.10 was a preliminary release, including a very limited number of commands crammed into 6 KB of object code.[4]
Disk[edit | edit source]
86-DOS 0.10 used a modified version of BASIC-86's FAT file system, chosen because of the small cluster sizes, speed, and error handling capabilities. The modifications included supporting 12-bit table elements (allowing for 64MB disks), and reducing the number of FATs from 3 to 2.[5] The filesystem was additionally adapted to allow for CP/M (8.3) filenames.[6]
Directory format[edit | edit source]
| Offset | Length | Field |
|---|---|---|
| 0 | 8 | Name |
| 8 | 3 | Extension |
| 11 | 2 | First Cluster |
| 13 | 3 | File Size |
File sizes are recorded in terms of bytes; however, like CP/M, files are accessed with record-granularity, with the size of a record being fixed at 128 bytes. This means all file sizes are divisible by 128.
Commands[edit | edit source]
86-DOS's commands were split into internal and external commands. External commands were .COM files in the root directory, while internal commands were not visible.[7]
| Command | Type | Source | Notes |
|---|---|---|---|
| DIR | Internal | [6] | |
| RENAME | Internal | [6] | |
| ERASE |
Internal |
[6] | |
| COPY | Internal | [8] | |
| TYPE | Internal | [9] | "It had all the basic utilities for assembly-language development except an editor" |
| ASM | External | [5] | Originally written in Z80 assembler as ASM86[10] |
| TRANS | External | [5] | Originally written in September 1979[11] in Z80 assembler as TRANS86[10] |
| HEX2BIN | External | [9] | "It had all the basic utilities for assembly-language development except an editor" |
While not counted as a command in the later version 0.3 manual, it should also be noted that 86-DOS had the ability to run executable files by inputting their filenames.[12][13]
Program Segment Prefix[edit | edit source]
86-DOS 0.10 created the Program Segment Prefix (PSP), a 256-byte data structure used to store program states.[12] It takes clear inspiration from CP/M-80's Zero Page, using a similar far call entry and exit.[14][15][16]
References[edit | edit source]
- ↑ 1.0 1.1 Hemmings, Bill (5 May 1999). Dos 1.1. comp.os.cpm.
- ↑ Hunter, David (March 1983). The Roots of DOS: Tim Paterson. Softalk for the IBM Personal Computer. p. 12-15.
- ↑ Paterson, Tim (4 August 2018). VCF West XIII -- Tim Paterson -- Original DOS and the old days. Vintage Computer Federation.
- ↑ Allen, Paul (2011). Idea Man. Penguin. p. 135. ISBN 1-59184-537-8.
- ↑ 5.0 5.1 5.2 Paterson, Tim (30 September 2007). Design of DOS. DosMan Drivel.
- ↑ 6.0 6.1 6.2 6.3 Paterson, Tim; Wharton, John (3 October 1994). From the Mailbox: The Origins of DOS. Microprocessor Report. p. 1-2.
- ↑ Paterson, Tim (December 1980). 86-DOS Version 0.3 User Manual. Seattle Computer Products.
- ↑ Manes, Stephen; Andrews, Paul (1993). Gates: How Microsoft's Mogul Reinvented an Industry—and Made Himself the Richest Man in America. Doubleday. p. 280-281. ISBN 0-385-42075-7.
- ↑ 9.0 9.1 Paterson, Tim (June 1983). A Short History of MS-DOS. BYTE Magazine. p. 246.
- ↑ 10.0 10.1 Microsoft Macro Assembler (MASM) Unofficial Changelist. BytePointer.
- ↑ United States District Court for the Western District of Washington (18 January 2007). Paterson v. Little, Brown, and Co., et al. - Deposition Upon Oral Examination of Tim Paterson. PACER. Case 2:05-cv-01719-TSZ Document 14-2.
- ↑ 12.0 12.1 Bornstein, Howard (1986). MS-DOS (Versions 1.0-3.2) Technical Reference Encyclopedia. Microsoft Press. p. 8. ISBN 0-914845-69-1.
- ↑ Duncan, Ray (1988). The MS-DOS Encyclopedia. Microsoft Press. ISBN 1-55615-049-0.
- ↑ Necasek, Michal (13 September 2011). Who needs the address wraparound, anyway?. OS/2 Museum.
- ↑ Brown, Ralf (July 2000). Format of Program Segment Prefix (PSP). Delorie Software.
- ↑ Jurgens, David (1991). DOS Program Segment Prefix Layout. HelpPC Reference Library.