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Text File | 1989-10-11 | 21.5 KB | 421 lines

Copyright (C) 1988, 1989 by FM de Monasterio All rights reserved May not be sold -------------------- BLANKs version 2.00 -------------------- BLANKs.COM is an IBM PC-/MS-DOS based, resident program that blanks the screen after a preselected interval in the absence of a keypress. This interval can be selected from 1 to 60 minutes. A selection higher than 60 minutes is set to 60. Selecting 0 minutes disables screen blanking; blanking can be enabled by re-invoking with an interval of 1 to 60 min. The program also offers the option of parking hard disk(s) heads at the time of blanking, of the use of a password to unblank the video, and of blanking the screen at the press of a selectable hot-key. BLANKs is a terminate-and-stay resident (TSR) program. When installed, the program uses less than 1000 bytes. It can be invoked repeatedly to change its settings without producing multiple copies to memory. BLANKs intercepts interrupts 8, 9 and 13h (and optionally 10h and 33h), and is a "well behaved" TSR intended to run under MS-DOS or IBM PC-DOS version 2.0x or higher. OPERATION The video blanking is obtained by direct commands to the hardware (video controller) to turn off/on the video signal. This is a fast method that operates successfully in the IBM PC/XT, PC/AT and in some IBM compatible computers installed with MDA, CGA, EGA, VGA, and Hercules video adapters or with IBM-compatible adapters from other manufacturers. NOTICE In some nonIBM microcomputers the program may not work and it should NOT be used with other video adapter types unless they are compatible with the IBM adapter at the register level (as it is possible that some of these adapters might be damaged). BLANKs intercepts the interrupts 8h (hardware timer), 9h (keyboard), 10h (BIOS video services), 13h (BIOS disk services), and 33h (mouse services for device drivers following the Microsoft/Logitech Mouse format). BLANKs will fail to operate if access to interrupts 8 and 9 is denied by another program or resident loaded after BLANKs. This might occur with a few communication and some word processing programs that take over these interrupts and fail to pass along the information to other programs that may be tapping the same interrupt vectors. - Interrupt 8h is issued 18.2 times/s to update the machine time-of-the-day counter (which is stored in the BIOS data area). Since a timer interrupt can thus only operate within a period of about 55 ms or less (*including* the overhead of DOS and other programs hooking on the timer), the program uses direct commands to the hardware, written in assembly language, which are issued, when needed, after the original timer interrupt is served. - Interrupt 9h is issued when a key on the keyboard is pressed or released. When the hotkey service is enabled (see switch /H below), BLANKs triggers blanking of the screen when the default hotkey combination (Ctrl-B in non shareware versions) is pressed. The hotkey code is then removed from the keyboard buffer; other keys are passed along for keyboard processing and, if blanking had occurred, the screen is restored. - Interrupt 10h is used to mediate a variety of video BIOS services. Since such services are comparatively slow, many programs make direct writes to the video (which are not detected by the resident part of BLANKs) instead of using BIOS video calls. - Interrupt 13h is used to mediate a variety of hard disk and diskette BIOS services. - Interrupt 33h (which is not used by DOS or the BIOS) is used in Microsoft and Logitech implementation of calls to the Mouse driver. This interrupt is claimed by the driver during its initialization. NOTICE To be able to monitor interrupt 33h, BLANKs must be installed *after* the mouse device driver, as otherwise the driver will not allow access to the interrupt. Also note that the driver for a well known mouse can freeze the machine if interrupt 33 is found to be in use at the time of installation. This does not occur with other drivers, e.g. Logitech's MOUSE.COM. BYPASSING INTERRUPTS While installed, BLANKs bypasses the interrupt 8 when a blanking interval of 0 minute has been selected (see below). Interrupt 9 is bypassed only when both an interval of 0 minute and the switch /H- (see below) have been selected. When /H- has been selected along with a nonzero interval, just the hotkey service of interrupt 9 is bypassed. Hence, these two interrupt activities of BLANKs are bypassed by the "0 /H-" selection; this may be of use in case of testing potential conflicts with other programs. Interrupts 10h and 33h are not intercepted when /K is selected; when this switch is not selected, these two interrupts are intercepted but they are not monitored unless switch /V is selected explicitly. Note that during cloning of the program, the status of switch /K is *not* copied as a default setting to the clone, as monitoring of video activity would otherwise be impossible irrespective of the status of switch /V. ---------------- USAGE From the DOS command line or from a batch file, BLANKs is installed (or, when already installed, modified) by the command: BLANKs [?] [min] [/switches] [;comments] 1. [?] Invokes a brief help and status display, identifying the type of adapter for which the program is configured, the current adapter, and program settings (if installed). If the program is not yet installed, its 16-bit CRC value is displayed; this value is calculated each time before loading, and the program will not install if an incorrect CRC is obtained (e.g., error in copying or downloading, malicious alteration of the code). Pressing key <F1> displays further help on using the program. If the program has not been installed, pressing <F2> displays the default settings of BLANKs. 2. [min] Timed blanking interval in minutes. These are the minutes that the program waits before blanking the screen in the absence of keyboard activity. Valid selections are 0 or a number in the range of 1 to 60. The selection of a 0-min interval disables the timed blanking of the screen; the selection of an interval larger than 60 defaults to 60 minutes for 2 digit inputs or to the value (in the valid range) of the first 2 digits in inputs containing larger numbers. Null interval defaults to 3 minutes; this value may be changed by cloning the program (see below). Using <T> rather than the digit(s) yields a 5-second interval for test purposes. 3. Several switches are recognized. While shown here preceded by a "/" for the sake of clarity, the program accepts any character between space ( ) and slash (/) as a switch delimiter. Invalid switches abort loading of the program. Switches are not case sensitive. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NOTE: Options marked with (*) are available in registered versions only. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ /A - Force configuration to specified adapter. This switch bypasses the automatic configuration of the program for the video adapter detected at the time of each calling. Valid specifications for this switch are: /Am configuration for the IBM Monochrome Display Adapter (MDA) and Hercules graphics cards (HGA, HGA plus, and In Color); uses and restores bit 3 of the video port 3B8h. /Ac configuration for the IBM Color Graphics Adapter (CGA), the Multi Color Graphics Array (MCGA) and compatibles; uses and restores bits 0-3 of port 3D9h and bit 3 of port 3D8h. /Ae configuration for the IBM Enhanced Graphics Adapter (EGA) and compatibles; reads video ports 3BAh and 3DAh, and uses and restores bit 5 of port 3C0h. /Av configuration for the Video Graphics Array (VGA); uses port 3C4h, and uses and restores bit 5 of port 3C5h. This configuration can be preserved as a default upon cloning of (the shareware version of) BLANKs. Switch /A is useful if video adapter type were incorrectly identified or an "unknown" result were obtained (see the Help display called by option "?"). See the above NOTICE on compatibility. /C - Clone to disk the current version of BLANKs installed in the memory.(*) This permits making the settings of this version the default ones. If the /C switch is entered in the command line alone, default parameters do not become effective (unlike the case of any other single switch specification) and the resident parameters are copied to the cloned file. If other switches or parameters are entered along with /C, these new parameters and, when applicable, defaults become effective, and are copied to the cloned file. The clone file BLANKs.COM is written to the default drive and directory. A warning is given if a file with the same name is present there, and the user has the option to overwrite it or to abort the cloning. Cloning will not overwrite files other than those with a normal or archive attribute, or both. /H - Hotkey switch. In addition to timed screen blanking, BLANKs allows for manual blanking of the video by pressing a hotkey combination. This combination is Ctrl-B in the nonshareware version of the program (see below). When BLANKs detects the hotkey, it removes it from the keyboard buffer. However, be aware that programs loaded after BLANKs may save this input; this is the case, for instance, with some word processors in which it is necessary to erase the hotkey character from the text. In the shareware version, the hotkey combination can be changed in case of assignment conflicts. /H+ Enable hotkey operation. This is the default condition when an argument is not specified for this switch. /H- Disable hotkey operation. Can be reenabled with /H+. /H? Permit the selection of a new hotkey combination (*) that includes an alphanumeric key and one or more of the shift keys <Ctrl>, <Alt>, <left-Shift>, and <right-Shift>. For obvious reasons, Ctrl or Alt, or both, have to be included in the new hotkey combination. /K - Force monitoring of keyboard activity only. If selected at the time of the (first) installation, the switch installs a shorter resident component of less than 800 bytes that disregards video activity via interrupt 10h and 33h. Because of the potential of hanging the computer if a request to uninstall were made after a change in the status of this switch, reinvocation of the program ignores /K switch requests. Hence, to change the status of this switch, BLANKs must be uninstalled and then reinstalled. The status of the flag associated with the /K switch is ignored during cloning, so that this switch cannot be set as a default. /P - Park the hard disk heads during manual or timed blanking of the screen. All physical hard disks attached to the disk controller that can be accessed via the BIOS are parked (uses highest disk cylinder). Parking is suppressed if a BIOS disk(ette) service is in progress at the time of blanking. /P+ Enable hard disk parking. This is the default condition when an argument is not specified for this switch. /P- Disable disk parking. Can be reenabled with /P[+]. /Q - Disable timed blanking. Produces the same effect as selecting an interval of 0 minute for the "T" option; it does not affect manual blanking with the hotkey combination. No defaults. /U - Uninstall. Use only when BLANKs was the last resident to be installed, as otherwise this would create a "hole" in memory. The request is not honored if vectors to interrupts 8, 9 and 10h have been changed since installation. This can be caused by a resident installed after BLANKs, or by a prior resident that changes vectors set by programs installed after it. You can determine if this is the case by using any of the memory mapping programs that are available: Search for interrupts 8 9 and 10; BLANKs.COM will be shown as an unnamed entry using 816 or 864 bytes, depending on the switch selections. (For a name to be seen in such memory maps, you must install BLANKs with the comment /V - Force monitoring of video activity mediated by BIOS/DOS calls to interrupt 10h and mouse calls to interrupt 33h. If enabled, switch /V avoids the timed blanking of the screen when video activity is detected; this switch, however, does not defeat a manual blanking of the screen, which can be unblanked only by keyboard activity (with or without a password -- see below). Switch /V function is negated by switch /K. Note: The video output of some programs is not made through these interrupts and, thus such activity will not be detected. Further, some mouse drivers can freeze the machine if interrupt 33h is found to be in use at the time of their initialization. (If you have such a driver and do not want to install it before BLANKs, you then need to install BLANKs with the /K switch, or uninstall BLANKs before installing the mouse device driver and then reinstall it with the /V switch.) /W - Password unblanking. A combination of up to 10 digits followed by <Right-Shift> is required to unblank the screen after MANUAL blanking; rebooting with <Ctrl-Alt-Del> keypress is blocked.(*) /W- Disable password unblanking. /W+ Re-enable use of the resident password (if no password had been loaded, the video will unblank only when <Right-Shift> is pressed). /W Request to specify a (new) password. Note: A password is not needed on TIMED blanking. Once enabled, password unblaking can be disabled either by switch "/W-" or by pressing <Esc> at the time a password is being specified. 4. Comments may be added after a ";" to clarify commands in a batch file. These comments, ignored by BLANKs, are removed from the invoking command line before loading and, thus, are not inherited by any clone of BLANKs. ---------------- RELEASE These programs and their documentation (the "Software") are the copyrighted property of F.M. de Monasterio. All rights are reserved. The Software, in its present nonshareware version, is distributed free of charge. Asking or charging donations for copies of this Software, or distributing such copies via a for-profit organization is specifically prohibited. Although lacking those options marked above with asterisks the nonshareware version is a usable program, being provided "as is" without warranty of any kind, either expressed or implied, including, but not limited to warranties of quality, performance, or fitness for any particular purpose. The entire risk as to the quality and performance of the Software is only on the user. REGISTRATION Registered versions of the Software for use on a SINGLE computer at a time may be licensed for a fee of US$10.00. Registered versions of the Software for use in more than one computer at a time (either by an individual or a commercial enterprise) may be licensed for a fee of US$30.00 for up to TEN computers at a single site or a set of contiguous sites. Upgrades within the same major version number of this Software (e.g., 2.00 through 2.99) are free of charge to registered users, and may be obtained by sending a self-stamped self-addressed diskette mailer with the original 360 kb diskette to the address below. Other upgrades are half the cost of the registration fee and may be ordered from the author (provide your name and registration number). Refer all inquiries about this Software to: F.M. de Monasterio ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 7013 Barkwater Ct. Bethesda, Md 20817 LICENSE Upon registration, the author grants you a non-exclusive, non-transferable license to use this Software. Ownership and title to the Software are not transferred to you by this license and both are retained by the author and copyright owner. - SINGLE-MACHINE LICENSE - The license grants you use of the Software on a single computer at a time. You may transfer the Software physically to another computer by having the enclosed diskette(s) read into the computer, provided that the Software is not used on more than ONE computer at any given time. - SITE/10-MACHINE LICENSE - The license grants you use of the Software at a single site or at a set of contiguous sites, provided that that the Software is not used on more than TEN computers at any given time. INJUNCTIONS You may distribute the Software via magnetic and/or electronic means, but you are specifically prohibited from: 1. Charging or asking donations for copies of the Software. 2. Distributing the Software with commercial products without the written permission from the author and copyright owner. 3. Distributing the Software via a for-profit organization, either alone or with other software. Unauthorized copying and/or disassembling of this Software is prohibited. Any other use of this Software is prohibited without the express, written permission in advance from the author and copyright owner. SUPPORT Limited technical support is provided to registered users only; if you find any problem, please try to replicate the problem under the same conditions, and then without the presence of other resident programs. (Often, a change in the order residents are loaded can solve conflicts.) If the problem can be replicated, please write at the address above providing: Your name, address, and a daytime phone number Program registration number (see the Help panel) Program version number (see the Help panel) A sufficiently detailed description of the problem(s) A list of all resident and nonresident programs in use and their loading sequence. LIMITATIONS The author makes no warranty, either implied or expressed, including, with- out limitation, any warranty with respect to this Software documented here, its quality, performance, or fitness for a particular purpose. In no event shall the author be liable for damage, whether direct, indirect, incidental, special, or consequential, that arises from the use of or any defect in the Software. The entire risk as to the quality and performance of the Software is solely with the user, and not with the author and copyright owner. By using the Software, you acknowledge: (1) to have read and understood all parts of this document, and (2) to have agreed with and accepted all of its provisions. Messages may be left: c/o Sysop (Bill Walsh) ~~~~~~~~~~~~~~~~~~~~ The DC Information Exchange BBS 202-433-6639 9600/2400 bps ┌──────────────────────────────────────────────────────────────────────────────┐ │ Designations claimed as trademark appear in initial capitals or all capitals │ └──────────────────────────────────────────────────────────────────────────────┘