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- docs/new/ — сводные справочники (архитектура, BIOS, DSS, память, графика, акселератор, IRQ, порты, ввод, звук, известные баги); - docs/Original/ — первоисточники, из которых они собраны (BIOS, Estex DSS, мануалы, описание акселератора), + Форум.doc/.docx в reference; - libbgi/common/gfx_scroll_h.c — обход бага скролла при ширине >256 (правка автора: шаг банды 255 и продвижение указателей на cw; старый вариант с 256 оставлен закомментированным с TODO); - удалён applications/PoP/roomtest/hang_variants.png — рабочая раскладка из разбора позы виса, в репозитории ей не место. Большие архивы (docs/extra ~568 МБ, docs/sources с вложенными git-репо ~68 МБ) в коммит НЕ включены — см. обсуждение. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
156 lines
4.7 KiB
Plaintext
156 lines
4.7 KiB
Plaintext
Estex: Disk SubSystem (DSS) Programming Guide
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Table of Contents
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1. Introducing
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2. Identification of system functions
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3. Disk devices functions
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1. Introducing
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This document contains the list of functions and concepts of
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interaction with a disk subsystem.
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DSS is a collection of very useful functions that reside in
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DSS itself, ready for use by any your programs. These functions
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are stored in library SYSTEM.DOS and allow management of files,
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memory allocation, loading and execution of the programs.
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File specification
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The file specification is a string, containing a names of disk,
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directories separated by a symbol "\" and name of file. The names
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of disk drive and directories can be discard.
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for example:
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C:\TEXT\DOC\text.doc
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A:file.txt
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\TEXT\info.txt
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The DSS used chars with colon suffix as names of disk devices
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(A:, B:, C: etc.) The name of disk can be written down before
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filename for specified disk there it placed.
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For example: command
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DIR C:DATFILE
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searches for DATFILE in the current directory of disk C:.
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When disk name not specified DSS used current disk. At start
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DSS, the current disk is a disk whence was loaded DSS.
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The filenames consist of two parts. The first part contain 8
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chars of file name. The second part is not necessary and contain
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3 chars of file type (also known as extentsion). At the writing
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of filename, both parts are separated by char point.
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For example: the names "NAME" and "NAME." is specified same file.
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In the name don't allows symbols with codes less 32 and chars
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. " / \ [ ] : | < > + = ; ,
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As the subdirectories files too, their names are formed by
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same way. The name of root directory always "\". And each
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subdirectories contain two items with names "." and "..". The
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name "." specified a current directory and name ".." specified
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name of parent(uplevel) directory.
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Some console commands and DSS functions allow to use global
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symbols ? and * which can be used for filename templates.
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The symbol ? means that any one char of filename. The
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symbol * means that it char can be replaced by any symbols.
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For example:
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*.txt - means, all files with type "txt"
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a??.* - means, files which contain three or less symbols and
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first symbol is "a"
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dc*.exe - means, files with type "exe" and began "dc"
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File attributes
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The each bit of byte attributes specified various attribute.
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And it can be changed by DSS function.
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bit 0 - Read only
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bit 1 - Hidden
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bit 2 - System
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bit 3 - Volume label
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bit 4 - Directory
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bit 5 - Archive
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bit 6 - Reserved
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bit 7 - Reserved
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Attribute "read only". When value is 1, file can be read,
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but can't be written or deleted.
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Attribute "hidden". When value is 1, DSS can't manipulate
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with this file.
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Attribute "system". Specified system file.
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Attribute "volume label". In old version of MSDOS used for
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specified volume laben, now it can be used for long filenames.
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And must be 0 for compatibles.
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Attribute "directory". When value is 1, means that this
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file is directory.
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Attribute "archive". This bite sets in 1 when DSS writing
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in this file. It can be used in backup utilities for detect
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changed files.
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File handle
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When any file are opened, DSS build File Control Block in
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DSS working areas.
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The Handle (and assigned file) identified by number which
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returned DSS to program after file opening and used it in all
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further DSS calls. In other words, when file is opening, the
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program informs DSS his name and has taken back file handle.
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Which used in further file operations.
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All necessary information for working with file are placed
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in DSS working areas.
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2. Identification of system functions
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00h (00) VERSION (Version of DSS)
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input:
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C - 00h
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output:
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D - version number
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E - modification
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The function return version number of DSS.
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3. Disk devices functions
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01h (01) CHDISK (Change current disk)
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input:
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A - disk number (0-A,1-B...)
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C - 01h
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output:
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A - error code, if CF=1
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A - number of disks, if CF=0
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The function changes current disk device.
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02h (02) CURDISK (Current disk number)
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input:
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C - 02h
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output:
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A - current disk number (0-A,1-B...)
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The function returns number of current disk device.
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03h (03) DSKINFO (Disk information)
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input:
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A - disk number (0-A,1-B...0FFh-current)
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C - 03h
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output:
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A - error code, if CF=1
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A - sectors per cluster, if CF=0
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HL - clusters per disk
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DE - free clusters
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BC - bytes per sector
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The function returns information about disk device
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(capacity and free space).
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for example:
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LD C,03h ;Function DSKINFO
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LD A,0FFh ;Information about current disk
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RST 10h ;Execution of function
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LD A,D ;There is a free
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OR E ;space?
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JR Z,NO_SPACE ;No, the disk is completely filled
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09h (09) BOOTDSK (Number of boot disk)
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input:
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C - 09h
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B = 0
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output:
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A - number of boot disk (0-A,1-B...)
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The function returns number of boot disk device whence was loaded DSS.
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