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- Author's Documentation:
-
- ZENO.COM: M. Lazarus, June 11, 1986
-
- ZENO is a small, fast, core-resident program that
- speeds up certain screen writes. The actual increase in speed is
- almost three-fold, but the increase you see on the screen depends
- on the application program in use. An example: with BCOMM
- operating at 9600 bps, the increase is approximately 20-30
- percent. Only certain programs take advantage of ZENO; but those
- that don't (including PC-Write) are usually fast enough without
- it.
-
- ZENO reduces available memory by about 900 bytes.
-
- ZENO operates with all screens. On some color screens,
- however, it may cause snow -- harmless but annoying. If that
- happens, remove ZENO with the instructions below.
-
- Important: Do not change back and forth between
- monochrome and color displays while ZENO is installed. Users of
- monochrome graphics boards: this includes you.
-
- To load: At the DOS prompt, type ZENO. A message will
- appear.
-
- To remove: At the DOS prompt, type ZENO/K (use no
- spaces; must be capital K). A message will appear. Important:
- First remove all core-resident programs loaded after ZENO.
-
- Additional Comments:
-
- (1) ZENO, like many other fast screen programs,
- eliminates the wait for the retrace. But ZENO also trys to speed
- up the BIOS routines in other ways as well. For details, see the ASM
- listing. Roughly speaking, ZENO assumes that the underlying
- program is trying to use the BIOS call in the most likely manner;
- it tests for that, and if the assumption is right, uses a faster
- method. If ZENO's assumptions are wrong, the test of the
- assumption slows down ZENO's performance in comparison to a
- program that only eliminates the retrace delay. Therefore, if
- the underlying program's use of INT 10 is extremely unusual,
- there may well be faster screen speedup programs faster than
- ZENO. But that is likely to be true only of very rare programs.
-
- (2) ZENOTEST.COM does nothing but a series of BIOS screen
- writes, counting timer interrupts. It then writes out the number
- of timer interrupts that have elapsed. Useful for comparing fast
- screen programs, although, obviously, it does not test them under
- all conditions.
-
- (3) Comments and suggestions are best addressed to me,
- David Seidman, on Bob Blacher's bulletin board, 202-547-2008.