Demacs, 386/486 DOS version of GNU Emacs

These nodes contains followings.

Overview:

Installation:

Invocation:

Features:

Appendix:

1 Demacs version 1.2.0

Demacs—386/486 DOS version of GNU Emacs.

1.1 Current Version

Demacs is currently based on GNU Emacs version 18.55 (partly 18.57).

Demacs version itself is 1.2.0 (1991/12/12).

Command: demacs-version

Return string describing the version of Demacs that is running.

1.2 Platforms

<Hardware>

386/486 based DOS machines—IBM PC and its compatible, AX, J-3100, or NEC PC-9801, High resolusion PC-98 and its compatible EPSON PC-386

<Software>

MSDOS 3.0 or later

XMS manager (‘HIMEM.SYS’) and VCPI memory manager (‘EMM386.EXE’, ‘QEMM’, etc.) compatible.

Demacs does not support DPMI, thus it can not be used with extended mode on Windows.

1.3 Bug Report

When you have troubles with using Demacs, please follow the following steps before inquire us.

First, read this README and the online-manuals (with Info Browser) to find answers. Next, consult to Emacs experts around you or on the networks. In case you decide to send a mail to the authors, you must read "Bugs" section in the Emacs manual before sending the mail.

Suggestions and bug fixes are welcome with next address.

demacs-bugs@sigmath.osaka-u.ac.jp

If you want to know current status about Demacs, send empty mail to next address.

demacs@sigmath.osaka-u.ac.jp

We will reply your mail with latest information, automatically.

2 Installation

2.1 Contents of This Distribution Kit

The package consists of two archives; ‘dem120e.lzh’ and ‘dem120s.lzh’. You need LHarc or LHa utility to unpack these archives. Don’t forget to use /mx switches with -x option to unpack them. For example do as following.

lharc x /mx dem120e.lzh
lharc x /mx dem120s.lzh

And similarly apply these options to the archives which are contained by them.

After unpacking, following files will appear.

‘dem120e.lzh’ (executables)

‘dem120s.lzh’ (source files)

NOTE:

This package only includes lisp files which are modified for Demacs. Original and/or other useful lisp stuff can be obtained from various FTP sites (for example ftp.sigmath.osaka-u.ac.jp) or from:

Free Software Foundation, Inc.
675 Mass Ave, Cambridge, MA 02139, USA

2.2 How to Install

Demacs requires special version of ‘go32.exe’ DOS extender. This package includes it with its name ‘bin\demacspc.exe’ for IBM PC or ‘bin\demacs98.exe’ for PC-9801 series. You should use one of them with renameing to ‘demacs.exe’.

Since go32.exe which came along with the package of DJ’s GCC/G++ version 1.05 can not handle Ctrl-C properlly, we modified it to work correctly. And we made some changes to be able to handle more DOS function call, and enhanced its memory management strategy (detail, see below).

Installation procedure is quite easy.

1. If your system is IBM PC variant (including AX and J-3100 series), copy ‘bin/demacspc.exe’ to the directory in PATH with its name ‘demacs.exe’.

   If your system is NEC PC-9801 or EPSON PC-386 series, copy ‘bin/demacs98.exe’ to the directory in PATH with its name ‘demacs.exe’.

2. Copy ‘bin\demacs’ in the same directory with ‘demacs.exe’.
3. Create ‘lisp’ and ‘etc’ directory in ‘\lib\emacs’ directory.
4. If you want to use lisp library, get original lisp files from somewhere and copy them in ‘\lib\emacs\lisp’ directory. Then unpack ‘lisp.lzh’ in ‘\lib\emacs’ directory.
5. Unpack ‘etc.lzh’ in ‘\lib\emacs’ directory.
6. Set TERM environment variable for your system (See following example).
7. Set TERMCAP variable if ‘termcap’ file is not stay under ‘\etc’.
8. Prepare your ‘_emacs’ (‘.emacs’ on Unix system) under your HOME directory if you need it.

2.3 Sample Session to Install

C> copy bin\demacspc.exe \tools\bin\demacs.exe (IBM PC, AX, J-3100)
C> copy bin\demacs \tools\bin
     or
C> copy bin\demacs98.exe \tools\bin\demacs.exe (PC-9801, PC-386)
C> copy bin\demacs \tools\bin

C> mkdir \lib\emacs
C> mkdir \lib\emacs\lisp
C> mkdir \lib\emacs\etc
C> copy lisp.lzh \lib\emacs
C> copy etc.lzh \lib\emacs
C> cd \lib\emacs
C> lharc x /mx lisp.lzh
C> lharc x /mx etc.lzh
C> del lisp.lzh
C> del etc.lzh

C> set TERM=ibmpc  (IBM PC)
      or
   set TERM=j3100  (J-3100)
      or
   set TERM=pc98   (PC-9801, PC-386)

C> set TERMCAP=c:\etc\termcap   (IBM PC, J-3100)
     or
   set TERMCAP=a:\etc\termcap   (PC-9801, PC-386)

C> set HOME=c:\home (your startup file '_emacs' is placed)

3 Invocation

3.1 Environment Variables

C>set GO32TMP=c:/tmp

directory where swapped files are placed (see DJGCC’s readme).

C>set TERM=ibmpc

entry name of ‘termcap’.

C>set TERMCAP=c:/etc/termcap

directory where ‘termcap’ file are placed.

C>set HOME=c:/home

directory where startup file ‘_emacs’ are placed.

C>set TZ=JST-9

time zone.

C>set USER=manabu

your name up to 8 characters.

C>set EMACSLOADPATH=d:/emacs/lisp

set lisp load path if you don’t use standard path ‘/lib/eamcs/lisp’.

C>set EMACSEXECPATH=d:/emacs/etc

set etc load path if you don’t use standard path ‘/lib/emacs/etc’.

C>set DEMACS_KEEP=1024

amount of extended memory to keep (detail, see below).

C>set SHELL=c:\command.com

your command interpreter path.

3.2 Options of DOS Extender demacs.exe

-keep [num]

When demacs.exe invokes a child process, demacs.exe does not swap out contents of the extended memory to a disk. If num is specified, demacs.exe uses up to num killo bytes of extended memory.

You should use this option with XMS or VCPI memory manager. If not, may cause violation.

More about -keep opiton:

demacs.exe provides virtual memory mechanism. If an application (e.g. Demacs) requires more memory than equipped real memory, demacs.exe write out a portion of real memory to a disk in order to make a free memory, then demacs.exe assigns the new free memory to the application. This is called “swapping”.

Swapping does not only happen when real memory shortage, but also happens when demacs.exe calls a child process. That is, before execution of the child process, demacs.exe swapps out all of allocated memory to a disk so that the child process can use memory. Unfortunatly, swapping takes very long time because Demacs is a huge program.

In order to eliminate this swapping time, our demacs.exe can take -keep option. -keep option requests to demacs.exe NOT to swap out contents of extended memory (conventional memory (less than 640KB) is always swapped out).

In case you use XMS driver such as ‘himem.sys’, since demacs.exe obtains all of free extended memory at startup, a child process can not use any extended memory (Remember GCC/G++ requires extended memory). You can reserve extended memory for the child process by following num to -keep, e.g. ‘-keep  1024’. num which is killo byte unit number limits amount of usage of extended memory by demacs.exe. If less amount of extended memory is available than num at startup, demacs.exe uses all of extended memory.

Otherwise in case you use VCPI driver such as QEMM or EMM386, demacs.exe gets extended memory on demand basis. ‘-keep num’ limits amount of extended memory used by demacs.exe to num killo bytes.

The following table shows a brief summary.

Too small num makes Demacs slower. I recommend to set num at least 512.

Example (Demacs uses 1024KB extended memory):

demacs.exe -keep 1024

num can be also specified by DEMACS_KEEP environment variable. If both environment variable and option are specified, option has priority. If you don’t need to specify num with -keep option, specify the value 0 with this environment variable.

3.3 Options of Demacs

Type demacs [-keep [num]] [options] to invoke Demacs. If you need more information, see “GNU Emacs manual”.

4 Features

4.1 File Type: Text or Binary Translation

4.1.1 Translation Mode

On MS-DOS file system, a line is ended with <CR> (0x0d)/<LF> (0x0a) characters and a file is ended with Ctrl-Z character. But on UNIX file system, a line is ended with only <LF> character, and end of data meas end of file.

Treating “binary files” which contains Ctrl-Z characters and for compatibility to UNIX file system, C I/O library on MS-DOS has following two translation mode which control these characters.

• Text mode translation
• Binary mode translation

With text mode translation, on reading, <CR>/<LF> code are translated to <CR> and reading is terminated as soon as Ctrl-Z appears. On writing, <LF> is added to <CR> and Ctrl-Z is added to end of file.

With binary mode translation, no code is translated.

Demacs supports these two translation mode, and manage them on each buffer. You can find current translation mode of the buffer from file type mnemonic on the mode line.

--**-Emacs: demacs.tex   (T:Texinfo)--42%---------------
                          ^

File type mnemonic means

T

Text mode translation.

B

Binary mode translation.

We call this translation mode which is managed on each buffer “file type”.

4.1.2 Demacs Buffer Management

4.1.2.1 File Type of Each Buffer

File type of each buffer is stored on buffer-local file-type variable. To set the value of file-type use the set-file-type function.

The default value of file-type is the value of default-file-type variable. To set its value, use the set-default-file-type function.

Local Variable: file-type

0

Text mode translation.

1

Binary mode translation.

Command: set-file-type TYPE &optional BUFFER

This function sets buffer-local file-type variable of BUFFER to TYPE. The argument BUFFER defaults to the current buffer. The value of TYPE is one of followings.

0 or 'text or "text"

Specify the buffer’s file type to text mode.

1 or 'binary or "binary"

Specify the buffer’s file type to binary mode.

Global Variable: default-file-type

The value of this grobal bariable is the default value of buffer-local file-type variable.

Command: set-default-file-type TYPE

This function sets the value of default-file-type variable to TYPE. The value of TYPE is one of followings.

0 or 'text or "text"

Specify the buffer’s file type to text mode, by default.

1 or 'binary or "binary"

Specify the buffer’s file type to binary mode, by default.

4.1.2.2 Buffer Creation

When creating a new buffer, Demacs set the buffer’s local variable file-type to the value of the default-file-type variable.

4.1.3 Reading Files into Demacs Buffers

Using the define-file-name-file-type function, you can define file type associated with file name.

For example,

(define-file-name-file-type "\\.mem$" 'binary)

defines that file type of files having extention ‘.mem’ is binary.

By default, the files ending with ‘.elc’, ‘.obj’, ‘.exe’, ‘.com’, ‘.lib’, ‘.sys’ (except ‘config.sys’), ‘.chk’, ‘.o’, ‘.a’ and ‘.out’ are defined as binary file type. This is defined in ‘demacs.el’.

Function: define-file-name-file-type FILENAME TYPE

This function defines file type associate with file name. FILENAME is regular expression or nil. nil matches any file anme. TYPE is file type.

Function: find-file-type-from-file-name FILENAME

This function returns file type which associate with FILENAME defined by define-file-name-file-type function. If no file type is defined, this returns a value of default-file-type.

4.1.3.1 Inserting Files into Buffers

When inserting a file already visiting buffer, Demacs calls the find-file-type-from-file-name function with file name of target file as its argument, and set return value to file type of the buffer.

4.1.3.2 Visiting Files and Reading

When visiting a file and reading into a buffer, Demacs calls the find-file-type-from-file-name function with file name of target file as its argument, and set return value to file type of the buffer.

4.1.3.3 Creating Files and Visiting

The find-file-not-found-set-file-type function is appended to the find-file-not-found-hooks variable. This means that find-file-not-found-set-file-type is called when the visiting file not exists.

This function calls internally the find-file-type-from-file-name function with target name as its argument and set return value to file type of the buffer.

4.1.4 Writing Buffers into Files

When writing a buffer into a file, Demacs set translation mode to file type of the buffer.

4.1.5 Process I/O

Demacs communicate with external process (child process) using temporary file. The default-file-type variable is used as file type of the buffer which displays result.

4.2 “8bit clean” Display Mode

Demacs supports so called “8bit clean” display mode, which displays 8bit dirty characters as it is instead of backslashed or arrowed form.

If you want use this mode, execute command toggle-pass8-mode. You can find in mode line whether the buffer is in “8bit clean” display mode.

--**-Emacs: foo.bar      (T:Fundamental Pass8)--28%---------------
                                        ^^^^^

To return ordinary display mode, again execute command toggle-pass8-mode.

If you want create a buffer always in “8bit clean” display mode, place

(setq-default pass8-mode t)

in your startup file.

Local Variable: pass8-mode

If this variable is *Non-nil, Demacs displays 8bit dirty characters as it is. Default value is nil.

Command: toggle-pass8-mode

Set/Unset the buffer local variable pass8-mode.

4.3 8086 Software Interrupt

Function int86 generate 8086 software interrupt. DOS Extender demacs.exe not handle all interrupts, so some interrupts are treated as exception and may cause violation. Use this carefully.

Use this function like this.

int
GetDisk ()
{
  union REGS regs;
  regs.h.ah = 0x19;     /* 25 */
  int86 (0x21 /* 33 */, &regs, &regs);
  return regs.h.al;
}

C funtion to get current disk number may write in Demacs as follows:

(defun get-disk ()
  (let ((regs (make-register)))
    (set-register-value regs 'ah 25)    ; 0x19
    (int86 33 regs)                     ; 0x21
    (register-value regs 'al)))

Function: make-register

Generate instance of register type which is passwd to int86 function.

Function: register-value REGISTER NAME

Get the value of REGISTER’s NAME. NAME is one of followings.

'ax

ax register

'bx

bx register

'cx

cx register

'dx

dx register

'si

si register

'di

di register

'cflag

carry flag

'flags

flag register

or

'al

lower byte of ax register

'ah

upper byte of ax register

'bl

lower byte of bx register

'bh

upper byte of bx register

'cl

lower byte of cx register

'ch

upper byte of cx register

'dl

lower byte of dx register

'dh

upper byte of dx register

Function: set-register-value REGISTER NAME VALUE

Set REGISTER’s NAME to VALUE. VALUE is unsigned integer.

Function: int86 INTNO REGISTER

Generate 8086 software interrupt of number INTNO with REGISTER. This returns set of register value.

4.4 Machine Specified Features

New lisp variable dos-machine-type is introduced for support various machines.

Global Variable: dos-machine-type

Set one of ibmpc, j3100, pc98 to select machine specific code.

4.4.1 IBM PC

If you use IBM PC, evaluate (setq dos-machine-type 'ibmpc), then Ctrl-<SPACE> will generate null code and meta-flag will works.

4.4.2 Toshiba J-3100

If you have J-3100, evaluate (setq dos-machine-type 'j3100), then following functions will be abailable in addition to IBM PC features.

set-cursor-mode
get-screen-mode
set-cursor-mode
set-keyclick
set-screen-mode

See ‘lisp/dos-fns.el’ for more information.

4.4.3 NEC PC-9801, EPSON PC-386

If you have PC-9801 or EPSON PC-386, evaluate (setq dos-machine-type 'pc98), then following functions will be abailable.

pc98-assign-special-key
pc98-cancel-special-key

See ‘src/dosfns.c’ for more information.

4.5 Other Demacs Features

1. Filename Completion

   Demacs provides filename completion feature. Filename may include drive name in its front. For example, we assume the current directory is ‘c:/tools/emacs’ and there is a file ‘d:/config.sys’, under this condition C-x C-f invokes find-file function then the function prompts like

   Find file: c:/tools/emacs/
   

   at this point your typing of d:/confi and <TAB> key causes:

   a:/tools/emacs/d:confi^I  -> d:/config.sys [sole complete]
   

2. Child Process

   Function suspend-emacs calls sub shell. Try C-z and a new command shell is invoked.

   Function call-process calls sub shell like suspend-emacs but its stdout is redirected to a temporary file and it will be displayed after completion of the process. Try M-!. But don’t call programs which require input from keyboard, because Demacs can’t response to them.

3. Enhanced Dired

   This package includes enhanced dired-mode by Sebastian Kremer and their dos ported codes which works without UNIX compatible ‘ls.exe’.

   To use this, extract ‘edired.lzh’ to your lisp directory and put lines

   (setq dired-mode-map nil)
   (load "emacs-19")
   (autoload 'dired "dired" nil t)
   

   to your startup file (‘direddos.elc’ is loaded from ‘dired.elc’).

   If you have ‘ls.exe’, append

   (setq dired-load-hook
         '(lambda ()
            (setq dired-ls-program "ls")))
   

   to your startup file. If you use Demacs with -keep option, this configration works faster than former one.

   You can get more infomation from ‘dired.README’ and its document string.

5 Restrictions

• Demacs does not support asyncronous process. Therefore you can not use standard ‘compile.el’, ‘shell-mode.el’ and etc. I think it’s too painful, so, customized ‘compiled.el’ and ‘dired.el’ are provided. See lisp directory.
• Ctrl-G can’t generate inturrupt signal. So you can’t quit lisp-form like this:

  (while t ())
  

  You shoud use the following form instead of it.

  (while (not (input-pending-p)) ())
  

• Demacs backup filename convension is following.

  Base backup filename is made from following rule.

  foo      ->  foo.~
  foo.c    ->  foo.c~
  foo.tex  ->  foo.te~
  

  Since DOS filename rule (8.3) is too tight, numeric backup such like ‘foo.c.~2~’ can not be used.

  Similarly auto save filename is made from following rule.

  abcdefgh ->  #abcdefg.#
  foo.c    ->  #foo.c#
  foo.tex  ->  #foo.te#
  

  Similarly, auto-save file name is created.

• If you don’t configure XMS or VCPI driver and invoke Demacs with -keep option, child process Demacs (or go32 application) will *not* work correctly.
• If you use VCPI manager and you have less extended memory than 300KB, Demacs will hang up or being to work *VERY* slowly. Plese give Demacs much memory if you met this.

6 Compilation

If you wish to recompile Demacs, ’GJ’s GCC/G++’ (GNU C compiler for DOS) and original Emacs source are required.

Diffs to the original Emacs source files are included in ‘src\diffs.lzh’. Unpack the archive. The files in ‘diffs.lzh’ are not diff form but they are full source files, so you need not to apply patch. You may need to alter makefile.

Then run ‘make -f xmakefile all’ command. Make generates temacs and demacs. Caution! just make will destroy ‘xmakefile’. I prepared ‘xmake.bak’ for you.

Note that all modifications are embeded by #ifdef MSDOS and #endif MSDOS, so you may follow my modifications easily. Machine specified codes are embedded in similar flags.

    *.h *.c (C source files)
       |
 ------| make
 |     | 
 |     V
 |   temacs (plain demacs) and lisp/*.el (lisp source files)
 |     | 
 |     | go32 temacs -batch -l loadup.el dump
 |---->|
       V
     xemacs

Provided ‘bin/temacs’ enables you to reconfigure demacs without recompilation. After editing lisp sources which are loaded up by ‘loadup.el’, run ‘go32 temacs -batch -l loadup.el dump’.

Appendix A Terminal Specified Features

If your machine is IBM PC or its compatibles, set environment variable TERM with ibmpc, then you can use cursor keys and functon keys.

The functions which is assigned to those keys are as follows:

Summary:

If you want to append and/or change the function, use lisp variable term-setup-hook. See ‘lisp/term/ibmpc.el’.

If you don’t need cursor and function keys, append next line to ‘$HOME/_emacs’:

(setq term-file-prefix nil)

Appendix B Differences from UNIX Version

List of Functions which are not inplemented to Demacs

accept-process-output                   process-list
continue-process                        process-mark
delete-process                          process-name
file-locked-p                           process-send-eof
get-buffer-process                      process-send-region
get-process                             process-send-string
interrupt-process                       process-sentinel
kill-process                            process-status
list-processes                          processp
make-symbolic-link                      quit-process
open-network-stream                     set-process-buffer
process-buffer                          set-process-filter
process-command                         set-process-kanji-code
process-exit-status                     set-process-sentinel
process-filter                          start-process
process-id                              stop-process
process-kanji-code                      waiting-for-user-input-p
process-kill-without-query

List of Variables which are not inplemented to Demacs

delete-exited-processes                 process-connection-type

List of Functions added to Demacs

bdos                                    intdos
define-file-name-file-type              invoke-find-file-type
demacs-version                          make-register
disk-free-space                         register-value
disk-total-space                        set-cursor-mode
file-type-internal                      set-default-file-type
file-type-p                             set-file-type
find-file-not-found-set-file-type       set-keyclick
find-file-type-from-file-name           set-register-value
get-cursor-mode                         set-screen-mode
get-screen-mode                         toggle-pass8-mode
int86

List of Functions added to Demacs

default-file-type                       file-type
demacs-version                          file-type-alist
demacs-version-date                     find-file-type
dos-inhibit-setdisk                     pass8-mode
dos-machine-type                        register-name-by-byte-alist
file-name-file-type-alist               register-name-by-word-alist

Appendix C Index

Functions

Variables

Table of Contents

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