Release Notes for Jcon
Version 2.1 of Jcon includes minor feature additions,
documentation edits, and bug fixes.
Changes include the following:
- A directory can be read by opening it as a file.
- JPEG images can be written under Java 2 implementations.
- Java class files can be bundled with a Jcon program for
easier dynamic loading.
- The run-time system can be bundled with a Jcon program
to make it completely self-contained.
- Large integers now work with
to-by,
seq(), limitation (e1 \ e2),
and exponentiation (e1 ^ e2)
- A zero increment value is diagnosed by
seq()
-
&host no longer spawns a shell invocation
of uname (but see Problems, below)
- The run-time package name has been changed from
rts
to jcon. All programs must be recompiled.
Tested Platforms
Jcon has been successfully tested on:
Sun Sparc / Solaris 2.6 (SunOS 5.6) / Sun Java 1.3beta0
SGI Indigo2 / Irix 6.5 / SGI Java 3.1.1 (JDK 1.1.6N)
IBM RS6000 / AIX 4.3 / IBM Java 1.1.6-19990401
DEC Alpha / Digital Unix 4.0D / Digital Java 1.1.6-2
Intel / Linux 2.2.5 (Red Hat 6.0) / IBM JDK 1.1.6-990814
We would be interested to learn of either successes or failures
on other platforms.
Known problems (nongraphical)
- Some JIT compilers fail to execute Jcon programs correctly.
Disabling the JIT compiler produces correct execution.
- The
-S option of jcont does not work
for programs that link other files.
&clock and &dateline
may be off by one hour (Java bug #4059431).
- On Solaris systems,
&host
may return "localhost" (Java bug #4073539).
- Extremely large procedures (thousands of lines long)
can generate code that is too large for Java to handle.
Known graphics problems
Some problems are universal:
- When an obscured part of a window is exposed,
it may not be repaired (redrawn) until the program
pauses to await an event.
WOpen("image=file.gif") does not load an image
if presented with a multi-part (animated) GIF image.
Other problems are seen only on some platforms and are
attributed to Java bugs:
- Fonts can be poor when one vendor's Java system displays
on another vendor's X server.
- Different fonts may be written to the window and to
and its backup image, leading to bizarre effects from
CopyArea() and window repair.
- On one older system, nothing appears in a window
until it is dragged to a different location.
- The initial window size may not be as specified:
- It is one pixel too wide, or
- It is always the default size, or
- Its height is correct but its width is the default.
- Intermittently,
drawop=reverse draws the wrong color.
- GIF images have a yellowish tint.
- The
CopyArea() section of the gpxtest
program shows a minor glitch.
index
|| intro
| usage
| differences
| graphics
| dynamic loading
| performance
| release notes
| installation
| references
|| home