add docs and readme.md

README.md

@@ -39,6 +39,7 @@ the [cc65 web site](https://cc65.github.io):
 | Dr. Jozo Dujmović       | Picocomputer (RP6502)               |
 | Watara                  | Watura/QuickShot Supervision        |
 | Synertek                | SYM-1                               |
+| USSR                    | Agat 7/9                            |
 
 A generic configuration to adapt cc65 to new targets is also around.
 

doc/agat.sgml

@@ -0,0 +1,79 @@
+<!doctype linuxdoc system>
+
+<article>
+<title>Agat-7/9 - specific information for cc65
+
+<author><url url="https://sourceforge.net/u/olegodintsov/profile/" name="Oleg A. Odintsov">,<newline>
+<url url="mailto:sintechs@gmail.com" name="Konstantin Fedorov">
+
+<abstract>
+An overview over the Agat-7 and Agat-9 and theirs interfaces to the cc65 C
+compiler.
+</abstract>
+
+<!-- Table of contents -->
+<toc>
+
+<!-- Begin the document -->
+
+<sect>Overview
+
+<p>The Agat was a series of 8-bit computers produced in the Soviet Union from 1983 to 1993. 
+It was based on Apple II architecture with all electronic components made in the Soviet Union except for 6502 microprocessors supplied by UMC (UM6502A).
+<p>If compared to Apple II, Agat had many improvements such as color text mode, additional graphic modes and flexible memory controller. 
+Agat-7 had an Apple II compatibility card called "Module 121", while Agat-9 had a built-in Apple II+ mode activated by soft-switch.
+<p>All mass-produced Agat models were disk-based systems, 2K ROM contained only basic machine language monitor and disassembler. 
+Agat-7 had 140K floppy-drive based on Apple DISK II, while Agat-9 was supplied with 840K drive having its own sector format and controller.
+
+<sect>Binary format<p>
+
+The standard binary file format generated by the linker for the Agat target is 
+an AppleSingle file to be compatible with AppleCommander <url url="https://applecommander.github.io/">.
+The default load address is &dollar;1903.
+
+
+
+<sect>Platform-specific header files<p>
+
+Programs containing Agat-specific code may use the <tt/agat.h/ or
+<tt/agat.inc/ include files.
+
+<sect>Usefull info<p>
+
+<sect1>Emulation<p>
+
+<enum>
+<item>  Oleg Odintsov's Agat Emulator - <url url="https://agatemulator.sourceforge.net/english.html">
+<item>  MAME - <url url="https://www.mamedev.org/">
+</enum>
+
+<sect1>Links<p>
+<enum>
+<item>  Most informative source on Agat (in russian) - <url url="https://agatcomp.ru">
+<item>  Wikipedia - <url url="https://en.wikipedia.org/wiki/Agat_(computer)">
+<item>  Controversial article on Agat from <url name="BYTE Magazine November 1984 Vol. 9, No. 12" url="https://archive.org/details/byte-magazine-1984-11/page/n135/mode/2up?view=theater">.
+The author reviewed custom-build mockup Agat bearing little relation to even the early Agat systems.
+</enum>
+
+
+<sect>License<p>
+
+This software is provided "as-is", without any expressed or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+<enum>
+<item>  The origin of this software must not be misrepresented; you must not
+        claim that you wrote the original software. If you use this software
+        in a product, an acknowledgment in the product documentation would be
+        appreciated, but is not required.
+<item>  Altered source versions must be plainly marked as such, and must not
+        be misrepresented as being the original software.
+<item>  This notice may not be removed or altered from any source
+        distribution.
+</enum>
+
+</article>

doc/index.sgml

@@ -109,6 +109,9 @@
 
 <descrip>
 
+  <tag><htmlurl url="agat.html" name="agat.html"></tag>
+  Topics specific to the Agat machines.
+
   <tag><htmlurl url="apple2.html" name="apple2.html"></tag>
   Topics specific to the Apple&nbsp;&rsqb;&lsqb;.