4.11.2014: game versions changed to remove errors
29.4.2014: error removed (compiled interpreter
buffer swap) and GAMING TRICK inserted
(how to play the 33 games with 1 fps on the ATARI ST 8MHZ),
also readable in this document.
XPRO Emulator ATARI is a XPRO VGA gaming console
emulator for the ATARI ST with monochrome
You can compile the monochrome versions of the 33
BrowserBasic games for that emulator, but it is
very slow. The monochrome versions can also be
played with XPROInterpreter. Then you must change
the line mulx=1 to mulx=4 in every game you
compile, because XPROEMUA bitblocks are smaller
in memory (XPROInterpreter still uses 16 colors).
The 33 compilable games use most of the
5000000 instructions per second to wait in
a for loop. Otherwise the next frame is
displayed too early. If you remove that loop,
you can play with about 1 frame per second
on your ATARI ST.
Find a sequence looking like the following
instructions in your compiled game.txt:
XXX varies from game to game. Simply search
for LOAD B,256 in your editor. If MULT A,B is the
next line and a LOOP follows, it is nearly
sure that you found the frame delay loop.
Change LOAD B,256 to LOAD B,0 and assemble
game.txt. The result runs with about 1fps
on a ATARI ST 8 MHZ.
Benchmark test results show, that XPROEMU ATARI
processes about 1000 XPRO instructions per
second. Basic programs process about 10000
comparable instructions per second.
The XPRO32 processor in the XPRO VGA console
is expected to execute 5000000 instructions
per second. This is the reason for the performance
gap. The small assembler program in the
folder TIMETEST executes 5242880 instructions.
It took more than 25 seconds. So a XPRO VGA emulator
for the ATARI must be about 25 times slower
than the XPRO VGA console. 8 MHZ is not
reached by the ATARI for more complex arithmetic
instructions (MULU, DIVU).
The BrowserBasic compiler must be run with
the AppletViewer from the JDK or be located
on a webserver location.