by default has only a small number of available open files, and this number is not adequate for the drivers with the value of five for MAXOPEN set in machdefs.h. You need to increase the limits by entering the lines
FILES=10 BUFFERS=10in the config.sys file in the boot directory, then reboot the system to have the new values take effect. Larger values are of course possible, though FILES=20 is the limit with current versions of . Run-time performance can be quite sensitive to these settings, so you may wish to experiment.
If there is no config.sys file, or the settings of FILES and BUFFERS are too small, you will find the disk whirring madly while the driver attempts to open font files with neighboring magnifications, and then it will finally die with a message ``unable to open .err file''. Use of the -d24 option may be useful in tracking how many files can successfully be opened (that is why I added that switch option).
The drivers have been loaded with the default Microsoft floating-point library; the compiler generates calls to library routines which test a flag initialized at startup time which indicates the presence or absence of the floating-point coprocessor chip. If it is available, the library routines will automatically use it. You can force the chip to be ignored by defining an arbitrary non-empty string value for the environment variable NO87, for example
set NO87=no-8087-availableWhen the DVI translator runs, the value of this variable should be typed on the screen as the first output line. On a Leading Edge PC, this typeout does not appear, for unknown reasons. On my 4.77MHz PC XT, the translators run twice (!) as slowly when NO87 is defined.
The reason that you might need to know this is that the method employed by the library routines for detecting the presence or absence of an 8087 (or 80287) chip is not infallible, thanks to design flaws of some PC's and possibly also the Intel chips. It is conceivable that the library might think a coprocessor chip is present, when in fact it is not, and the first floating-point instruction executed would hang the machine.