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EMS Library For the C Language (EMS4C) USERS MANUAL Version 1.0 July 24, 1993 This software is provided as-is. There are no warranties, expressed or implied. Copyright (C) 1993 All rights reserved MarshallSoft Computing, Inc. Post Office Box 4543 Huntsville AL 35815 205-881-4630 Voice / FAX 205-880-9748 Support BBS EMS4C Users Manual Page 1 C O N T E N T S Chapter Page 1.0 Introduction..............................................3 1.1 Distribution Files....................................3 1.2 Compiling the Library.................................4 1.3 User Support..........................................4 1.4 Installation..........................................5 2.0 MSDOS Memory..............................................6 2.1 Types of Memory.......................................6 2.2 Bank Switching........................................6 3.0 Example Programs..........................................7 3.1 EMS_TEST..............................................7 3.2 EMS_STAT..............................................7 3.3 The EMM4C Library.....................................7 4.0 EMS Library Functions.....................................8 4.1 emsLoaded............................................9 4.2 emsGetStatus.........................................9 4.3 emsGetFrame..........................................10 4.4 emsGetPages..........................................10 4.5 emsAllocate..........................................11 4.6 emsMapMemory.........................................12 4.7 emsRelease...........................................13 4.8 emsVersion...........................................13 4.9 emsSaveMap...........................................14 4.10 emsRestoreMap........................................14 4.11 emsGetHandles........................................15 4.12 emsOwnedPages........................................15 4.13 emsPageInfo..........................................16 4.14 emsError.............................................17 5.0 EMS4C Error Codes.........................................18 6.0 Legal Issues..............................................19 6.1 Registration..........................................19 6.2 Referral Program......................................19 6.3 License...............................................20 6.4 Warranty..............................................20 7.0 Revision History..........................................20 8.0 Other MarshallSoft Computing Products for C...............21 8.1 The Personal Communications Library for C.............21 8.2 The Personal Protocol Library for C...................21 8.3 The LZW Data Compression Library for C................22 EMS4C Users Manual Page 2 1.0 Introduction The EMS4C library implements version 3.2 of the LIM (Lotus-Intel-Microsoft) specification for expanded memory. It will run with either version 3.2 or 4.0 of the LIM specification. In order to use the EMS4C library, you must have either an EMS memory board installed, or have an expanded memory emulation driver program (such as EMM386 or 386MAX) installed. The EMS4C library provides 14 functions which allow the user to make use of expanded memory from their programs. Several example programs are also provides such as: EMS_STAT : Displays EMS driver status. EMS_TEST : EMS4C library test program. 1.1 Distribution Files EMS4C.H : EMS4C prototype file. EMS4C_S.LIB : EMS4C small model library. EMS4C_L.LIB : EMS4C large model library. EMS4C_S.MIX : MIX Power C small model object file. EMS_ERR.C : Error message file. EMS_TEST.C : Source code for the EMS4C test program. EMS_TEST._T_ : Borland C & Turbo C makefile for EMS_TEST. EMS_TEST._M_ : Microsoft C makefile for EMS_TEST. EMS_TEST._Q_ : Microsoft Quick C makefile for EMS_TEST. EMS_STAT.C : Source code for the EMS4C status program. EMS_STAT._T_ : Borland C & Turbo C makefile for EMS_TEST. EMS_STAT._M_ : Microsoft C makefile for EMS_TEST. EMS_STAT._Q_ : Microsoft Quick C makefile for EMS_TEST. Registered users also receive: EMS4C.ASM : Source code for EMS4C library. EMS4C_C.LIB : EMS4C compact model library. EMS4C_M.LIB : EMS4C medium model library. EMS4C_C.MIX : MIX EMS4C compact model object. EMS4C_L.MIX : MIX EMS4C large model object. MAKE_S.BAT : Makes EMS4C_S.LIB from source. MAKE_M.BAT : Makes EMS4C_M.LIB from source. MAKE_C.BAT : Makes EMS4C_C.LIB from source. MAKE_L.BAT : Makes EMS4C_L.LIB from source. MAKE_XS.BAT : Makes EMS4C_S.MIX from source. MAKE_XC.BAT : Makes EMS4C_C.MIX from source. MAKE_XL.BAT : Makes EMS4C_L.MIX from source. EMS4C Users Manual Page 3 1.2 Compiling the Library The registered user can re-assemble the source code (source code is provided in the registered version only) for the library using one of the provided batch files ( MAKE_S.BAT, etc.). Note that you will need a Microsoft compatible assembler such as MASM.EXE in order to create new EMS library files. Makefiles are provided for re-assembling the libraries. For example, to create EMS4C_S.LIB, type: MAKE_S 1.3 User Support We want you to be successful in developing your application using our libraries! We depend on our customers to let us know what they need in a library. This means we are committed to providing the best libraries that we can. If you have any suggestions or comments, please write to us or give us a call. If you are having a problem using EMS4C or any of our libraries, call (205) 881-4630 between 5 PM and 9 PM CST Monday through Friday. You can call at other times and leave a message, and call back later during our regular business hours for a reply. You can also FAX us at this same number at any time. You may also call our 24 hour BBS (2400 baud, no parity, 8 data bits, 1 stop bit) at any time. The BBS will contain the latest shareware version of EMS4C, messages, and other related files. All files are in standard ZIP format. You can leave a message on the BBS, and we will usually have a reply ready for you within 24 hours. The dedicated telephone number is 205-880-9748. Set your modem for 1200 to 9600 baud, 8 data bits, no parity, one stop bit. The MarshallSoft Computing, Inc. newsletter "Comm Talk" is published quarterly. It discusses various communications problems and solutions using PCL4C (the communications library) as well as related information such as data compression issues. Registered users receive a one year complimentary subscription when first registering and for each update purchased. Additional one year subscriptions are $15 plus $5 for overseas postage (postpaid in the US). EMS4C Users Manual Page 4 1.4 Installation (1) Microsoft C, Borland & Turbo C, and MIX Power C compilers are supported. However, the code should work with most any C compiler. Before installation of EMS4C, your C compiler should already be installed on your system and tested. If you are not familiar with makefiles, refer to your compiler manual. If you are using the interactive environment for Quick C or Turbo C, be sure to compile with the memory model corresponding to the EMS4C library used. (2) Make a backup copy of your distribution disk. Put your original distribution disk in a safe place. (3) Create a work directory on your work disk (normally your harddisk). For example, to create a work directory named EMS4C, we first log onto the work disk and then type: MKDIR EMS4C (4) Copy all the files from your backup copy of the distribution disk to your work directory. For example, to copy from the A: drive to your work directory, we type: CD EMS4C COPY A:*.* (5) Compile EMS_STAT.C and EMS_TEST.C and link with the appropriate EMS4C library For example, to make EMS_TEST.EXE: a) Borland Turbo C: Type MAKE -fEMS_TEST._T_ b) Microsoft C: Type MAKE EMS_TEST._M_ c) Quick C: Type MAKE EMS_TEST._Q_ d) MIX Power C: Type X_TEST_T EMS4C Users Manual Page 5 2.0 MSDOS Memory 2.1 Types of Memory Your system can have three kinds of memory: Conventional, extended, and expanded. All computers have "conventional" memory which includes all memory up to 640KB, also known as "lower" DOS memory. The memory above 640KB to 1MB (1024KB) is known as "upper" DOS memory, which is used by MSDOS for device driver, video buffers, etc. Programs running under MSDOS can address all memory up to 1MB. Extended memory is available on 80286 systems and up. To use extended memory, you must install an extended-memory manager such as HIMEM.SYS (distributed with MSDOS 5.0 & up). Extended memory can also be converted to expanded memory as explained below. The last type of memory on MSDOS systems is "expanded" memory. Two kinds of expanded memory exists, both of which are handled identically by EMS4C. The first type of expanded memory is an expanded memory board that you install in your computer. Expanded memory boards can be installed in any IBM PC beginning with the 8088 processor. Refer to the directions that came with your board. The second type of expanded memory is really extended memory that has been converted to expanded memory by a expanded-memory emulator such as EMM386 (distributed with MSDOS 5.0 & up), 386MAX, etc. Expanded memory created from extended memory behaves in exactly the same way as true expanded memory. 2.1 Bank Switching Expanded memory is implemented by a technique where more than 1MB can be used by MSDOS programs, which are limited to addressing 1MB of memory. This is done by a technique called "bank switching" in which up to 32MB (in EMS 4.0) can be referenced in 16KB blocks within the 1st 1MB of memory. The expanded memory is organized into contiguous 16KB pages, which can be mapped into any of four contiguous 16KB page frames located somewhere between 640KB and 1024KB. The mapping is controlled by the EMS driver using interrupt 67H. The EMS4C library provides the interface necessary to perform this bank switching from within your C program. EMS4C Users Manual Page 6 3.0 Example Programs Two example programs are provided. Each example program should be compiled with the provided makefile. These example programs are meant to demonstrate various ways in which the EMS compression library can be used. If you are using an integrated compiler environment instead of makefiles, notice that each program is compiled with the SMALL memory model. 3.1 EMS_STAT EMS_STAT will display all EMS parameters (such as the amount of EMS memory available) on your system. To run EMS_STAT, just type: EMS_STAT 3.2 EMS_TEST The EMS_TEST program tests each of the EMS4C library functions. The program also exercises the memory mapping calls, verifying that all mapping is performed without data loss. To run EMS_TEST, just type: EMS_TEST 3.3 The EMM4C Library The EMM4C (Expanded Memory Manager for C Library) library is provided as a final example of using the EMS4C library. The EMM4C library implements memory allocation and de-allocation functions for EMS memory similiar to the standard C runtime library functions malloc() and free(). There is also a EMM4C test driver provided with the EMM4C library that exercises the EMM4C functions. The EMM4C test driver (EMM_TEST) operates similiarly to the EMS4C test driver. The EMM4C library is documented in the EMM4C.DOC file. A registered version of the EMM4C library is provided when the user registers the EMS4C library. EMS4C Users Manual Page 7 4.0 EMS Library Functions There are 14 functions in the EMS4C library. emsLoaded Verifies that an expanded memory driver is loaded. emsGetStatus Verifies that EMS hardware (if installed) is OK. emsGetFrame Returns the address of the 1st EMS frame. emsGetPages Gets the # free pages & the total # pages. emsAllocate Allocates requested EMS pages. emsMapMemory Maps an EMS page to a page frame. emsRelease Release previously allocated EMS pages. emsVersion Gets EMS driver (EMM) version. emsSaveMap Saves EMS mapping context. emsRestoreMap Restores a previous saved EMS mapping context. emsGetHandles Get number of active EMS handles. emsOwnedPages Returns the number of pages owned by a handle. emsPageInfo Returns handles & pages for all handles. emsPageMap Gets or sets EMS page-mapping registers. All error codes returned by EMS4C are those returned by the EMS driver, except for error codes 0xA0, 0xA1, and 0xA2. This library should only be used with EMS version 3.2 or 4.0. Earlier versions of the EMS may not work properly. EMS4C Users Manual Page 8 4.1 emsLoaded Function: Verifies that an expanded memory driver is loaded. Syntax: int emsLoaded(void); Remarks: You must call emsLoaded before any other EMS4C function in order to verify that an expanded-memory driver is loaded. Returns: 0 : No error. 0xa0: EMS driver not loaded. 0xa1: Illegal library modification. (Shareware only). Example: /* is EMS driver loaded ? */ Code = emsLoaded(); if( Code != 0 ) {/* error returned ! */ printf("emsLoaded returns %x\n",Code); ... } See Also emsGetStatus 4.2 emsGetStatus Function: Verifies that EMS hardware (if installed) is OK. Syntax: int emsGetStatus(void); Remarks: The emsGetStatus() function should be called immediately after call emsLoaded(). Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. Example: /* check EMS driver status */ Code = emsGetStatus(); if( Code != 0 ) {/* error returned ! */ printf("emsGetStatus returns %x\n",Code); ... } See Also emsLoaded. EMS4C Users Manual Page 9 4.3 emsGetFrame Function: Returns the address of the 1st EMS frame. Syntax: int emsGetFrame(SegmentP) int *SegmentP; /* pointer to segment of page frame */ Remarks: The emsGetFrame() function is used to get the segment address of the first page frame. The four page frames are all 16KB (16,384) bytes in length and occupy contigous space in the area between 640KB and 1MB. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. Example: /* get the frame segment */ int SegmentP; Code := emsGetFrame(&SegmentP); printf("Frame 0 address is at %x:0000\n",SegmentP); 4.4 emsGetPages Function: Gets the # free pages & the total # pages. Syntax: int emsGetPages(FreePagesP,TotalPagesP) int *FreePagesP; /* pointer to # of free pages */ int *TotalPagesP; /* pointer to # of total pages */ Remarks: The emsGetPages function gets the nummber of system wide unallocated (free) pages, and also the total number of pages. You may subsequently allocate no more than the number of free pages reported by this function. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. Example: /* get # free and total pages */ int Code; int FreePages; int TotalPages; ... Code = emsGetPages(&FreePages,&TotalPages); See Also emsAllocate EMS4C Users Manual Page 10 4.5 emsAllocate Function: Allocates requested EMS pages. Syntax: int emsAllocate(NumberPages,HandleP) int NumberPages; /* number of pages to allocate */ int *HandleP; /* pointer to handle */ Remarks: The emsAllocated function attempts to allocate the requested number of pages, which must be less tna or equal to the number of free pages as return by emsGetPages. The Handle (returned) must be used for subsequent calls to the remaining EMS functions. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. 0x85: No more handles available. 0x87: Logical pages not available. 0x88: Logical pages not currently available. 0x89: Zero pages requested. Example: /* get # free and total pages */ int Code; int NumberPages; int Handle; ... Code = emsAllocate(&NumberPages,&Handle); See Also emsGetPages, emsRelease. EMS4C Users Manual Page 11 4.6 emsMapMemory Function: Maps an EMS page to a page frame. Syntax: int emsMapMemory(PhysicalPage,LogicalPage,Handle) int PhysicalPage; /* Physical page (frame) number (0-3) */ int LogicalPage; /* Logical page number */ int Handle; /* EMS handle */ Remarks: The emsMapMemory function maps the requested page to the the requested frame. Once the page has been successfully mapped, you may address the contents of the page at the frame addresss. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. 0x8a: Logical page not assigned to this handle. 0x8b: Physical page number invalid. Example: /* map memory */ int Page; int Frame; int Handle; ... Code = emsMapMemory(Page,Frame,Handle); See Also emsAllocate(). EMS4C Users Manual Page 12 4.7 emsRelease Function: Release previously allocated EMS pages. Syntax: int emsRelease(Handle) int Handle; /* EMS handle */ Remarks: The emsRelease function releases memory previously allocated with emsAllocate(). Once memory is released, you can no longer reference it through the page frame. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. 0x86: Error in mapping context. Example: /* release memory */ int Handle; ... Code = emsRelease(Handle); See Also emsAllocate(). 4.8 emsVersion Function: Gets EMS driver (EMM) version. Syntax: int emsVersion(VersionP) int *Version; /* pointer to version number */ Remarks: The emsVersion function returns the Expanded Memory Manager (EMM). The EMS4C library supports versions 3.2 and 4.0 (the two most recent as of this date). Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. Example: /* get EMM version # */ int Version; int Code; Code = emsVersion(&Version); EMS4C Users Manual Page 13 4.9 emsSaveMap Function: Saves EMS mapping context. Syntax: int emsSaveMap(Handle) int Handle; /* EMS handle */ Remarks: The emsSaveMap function saves the current EMS mapping context. You will only need to call this function if you are writing a memory resident (TSR)program, an interrupt service routine (ISR), device driver, or other code that will have to share the EMS with other programs at runtime. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. 0x8c: Page-mapping hardware state save area full. 0x8d: Mapping context already associated. Example: /* save mapping context */ int Handle; int Code; Code = emsSaveMap(Handle); See Also emsRestoreMap 4.10 emsRestoreMap Function: Restores a previous saved EMS mapping context. Syntax: int emsRestoreMap(Handle) int Handle; /* EMS handle */ Remarks: The emsRestoreMap() function restores the mapping context previously saved with emsSaveMap(). Note that at most one mapping context can be saved at any one time. Refer to the emsSaveMap() function. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. 0x8e: Save area has no context for handle. Example: /* restore mapping context */ int Handle; int Code; Code = emsRestoreMap(Handle); See Also emsSaveMap EMS4C Users Manual Page 14 4.11 emsActiveHandles Function: Get number of active EMS handles. Syntax: int emsActiveHandles(HandlesP) int *HandlesP; /* pointer to number of handles */ Remarks: The emsActiveHandles() function gets the number of active EMS handles already allocated. If 0 is reported, then EMS is not in use. There is a system wide maximum of 255 handles. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. Example: /* report # free EMS handles */ int Code; int Handles; Code = emsActiveHandles(&Handles); if(Handles>0)printf("%d free handles\n",255-Handles); See Also emsOwnedPages 4.12 emsOwnedPages Function: Returns the number of pages owned by a handle. Syntax: int emsOwnedPages(Handle,OwnedP) int Handle; /* EMS handle */ int OwnedP; /* pointer to owned handles */ Remarks: The emsOwnedPages() function gets the number of handles owned by the specified EMS handle. The minimum value is one. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x83: Invalid handle. 0x84: Undefined function. Example: /* report # owned pages */ int Code; int Owned; int Handle; ... Code = emsOwnedPages(Handle,&Owned); printf("%d pages owned by handle %d\n",Owned); See Also emsActiveHandles EMS4C Users Manual Page 15 4.13 emsPageInfo Function: Returns handles & pages for all handles Syntax: int emsPageInfo(PagesP,ActiveP) int *PagesP; /* pointer to array to hold info */ int *ActiveP; /* pointer to # active pages */ Remarks: The emsPageInfo() function fills a passed array with 4-byte entries of handles & page counts: Bytes 0 &1 contain the EMS handle, while bytes 2 & 3 contain the number of pages. Be sure to pass an array of sufficient size to contain all entries. Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. Example: /* get page info */ int Code; int Active; struct {int Handle; int Pages; } Array[255]; ... Code = emsPageInfo(&Array,&Active); EMS4C Users Manual Page 16 4.14 emsPageMap Function: Gets or sets EMS page-mapping registers. Syntax: int emsPageMap(Function,SrcArray,DstArray,*Result) int Function; /* sub-function */ char SrcArray[]; /* pointer to source array */ char DstArray[]; /* pointer to dest. array */ int *Result; /* pointer to Result */ Remarks: The emsPageMap function is used to get or set page map registers, or get the size of the Page Map array. This function is designed to support multi-tasking DOS extenders such as Windows. The Result variable will contain the page map array size if emsPageMap was called successfully with sub-function 3. The emsPageMap function should not be used for programs other than multi-tasking Operating Systems. It is included in the EMS4C library for completeness only. Subfunction values are: 00H = Getting registers into array 01H = Setting registers from array 02H = Get and set operation 03H = Return size of page-mapping array Returns: 0x00: No error. 0x80: Internal error in EMS software. 0x81: Malfunction in EMS hardware. 0x84: Undefined function. 0x8f: Subfunction not defined. Example: /* get size of page mapping array */ char SrcArray[], DstArray[]; int Result; ... Code = emsPageMap(3,SrcArray,DstArray,&Result); if(Code==0) printf("Array size = %d\n",Result); EMS4C Users Manual Page 17 5.0 EMS Error Codes Be sure and check the return codes from each EMS4C function call. There are 18 error codes returned by the EMS4C library other than 0 (no error). All error codes are negative numbers. Their numerical values are the same as returned from the MSDOS EMS Driver (EMMXXXX0) and are defined in the EMS4C.H file. EMS Error Codes ************************************************************** * 0x00 * No error. * * 0x80 * Internal error in EMS software. * * 0x81 * Malfunction in EMS hardware. * * 0x83 * Invalid handle. * * 0x84 * Undefined function. * * 0x85 * No more handles available. * * 0x86 * Error in mapping context. * * 0x87 * Logical pages not available. * * 0x88 * Logical pages not currently available. * * 0x89 * Zero pages requested. * * 0x8a * Logical page not assigned to this handle. * * 0x8b * Physical page number invalid. * * 0x8c * Page-mapping hardware state save area full. * * 0x8d * Mapping context already associated. * * 0x8e * Save area has no context for handle. * * 0x8f * Subfunction not defined. * * 0xa0 * EMS driven not loaded. * * 0xa1 * Illegal library modification. (Shareware only). * * 0xa2 * emsLoaded not called. * ************************************************************** EMS4C Users Manual Page 18 6.0 Legal Issues 6.1 Registration If you wish to register the EMS4C library, please send $35 plus $3 S&H ($6 outside of North America) to: MarshallSoft Computing, Inc. Post Office Box 4543 Huntsville AL 35815 We accept American Express (account number, expiration date, exact name on your card, and complete AmEx billing address required), checks in US dollars drawn on a US bank, purchase orders (POs) from recognized US schools and companies listed in Dun & Bradstreet, and COD (street address and phone number required) within the USA (plus a $3 COD charge). Print the file EMS4C.INV if an invoice is needed. You can also order EMS4C from The Public Software Library (PSL) with your MC, Visa, AmEx, or Discover card by calling 800-242-4PSL (from overseas: 713-524-6394) or by FAX at 713-524-6398 or by CompuServe at [71355,470]. THESE NUMBERS ARE FOR ORDERING ONLY. The product number for EMS4C is 10912. If you wish to update from an older version of EMS4C, send $15 plus $3 S&H ($6 outside of North America). Updates must be ordered directly from MarshallSoft Computing. The registered package includes: o No shareware screen. o Assembler source code for the library. o Laser printed Users Manual. o Telephone / FAX / BBS support for one year. o The EMM4C library. Print the file EMS4C.INV if an invoice is needed. The registered user will receive the latest version of EMS4C shipped by two day priority mail (packet airmail overseas). A 5.25" diskette is provided unless a 3.5" diskette is requested. 6.2 Referral Program The registered user will receive a $5 certificate towards any MarshallSoft Computing product by referring a new customer (someone who has never registered with us). The new customer must identify you at the time the order is placed. You will be mailed a certificate worth $5 when the new registration is paid. EMS4C Users Manual Page 19 6.3 License MarshallSoft Computing, Inc. grants the registered user of EMS4C the right to use the EMS4C library (in object form) in the development of any software product without any royalties. However, the source code (EMS4C.ASM) for the library is copyrighted by MarshallSoft Computing, Inc., and may not be released in whole or in part. 6.4 Warranty MARSHALLSOFT COMPUTING, INC. DISCLAIMS ALL WARRANTIES RELATING TO THIS SOFTWARE, WHETHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, AND ALL SUCH WARRANTIES ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. NEITHER MARSHALLSOFT COMPUTING, INC. NOR ANYONE ELSE WHO HAS BEEN INVOLVED IN THE CREATION, PRODUCTION, OR DELIVERY OF THIS SOFTWARE SHALL BE LIABLE FOR ANY INDIRECT, CONSEQUENTIAL, OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE SUCH SOFTWARE EVEN IF MARSHALLSOFT COMPUTING, INC. HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES OR CLAIMS. IN NO EVENT SHALL MARSHALLSOFT COMPUTING, INC.'S LIABILITY FOR ANY SUCH DAMAGES EVER EXCEED THE PRICE PAID FOR THE LICENSE TO USE THE SOFTWARE, REGARDLESS OF THE FORM OF THE CLAIM. THE PERSON USING THE SOFTWARE BEARS ALL RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE. Some states do not allow the exclusion of the limit of liability for consequential or incidental damages, so the above limitation may not apply to you. This agreement shall be governed by the laws of the State of Alabama and shall inure to the benefit of Marshallsoft Computing, Inc. and any successors, administrators, heirs and assigns. Any action or proceeding brought by either party against the other arising out of or related to this agreement shall be brought only in a STATE or FEDERAL COURT of competent jurisdiction located in Madison County, Alabama. The parties hereby consent to in personam jurisdiction of said courts. 7.0 Revision History Version 1.0 -- July 24, 1993 -- original release. EMS4C Users Manual Page 20 8.0 Other MarshallSoft Computing Products for C Shareware versions of all MarshallSoft Computing products are available on our user support BBS 205-880-9748. 8.1 The Personal Communications Library for C The Personal Communications Library for the C Language (PCL4C) is an asynchronous communications library designed for experienced software developers programming in C. Four compilers are supported: Microsoft Optimizing C, Microsoft Quick C, Borland Turbo C, and MIX Power C. An IBM PC/XT/AT or compatible is required. The PCL features: o SMALL, COMPACT, MEDIUM & LARGE memory models. o 33 communications and support functions. o Supports PC/4 and PC/8 Digiboard. o Support for the high performance INS16550 UART. o Supports hardware (RTS/CTS) flow control. o Interrupt driven receiver. o Supports 300 baud to 115,200 baud. o Supports COM1, COM2, COM3, and COM4. o Adjustable receive queues from 8 bytes to 32 KB. o Control-BREAK error exit. o 17 communications error conditions trapped. o Allows 4 ports to run concurrently. o Complete modem control & status. o Written in assembly language for small size & high speed. o Terminal program featuring XMODEM, YMODEM, & YMODEM-G. The Personal Communications Library for C (PCL4C) is available for $55 plus $3 S&H ($6 S&H overseas). It may be ordered at the same time as the Personal Protocol Library for $65 plus $3.50 S&H ($7 overseas). 8.2 The Personal Protocol Library for C The Personal Protocol Library (PPL) consist of a state driven library which implements the XMODEM, XMODEM-CRC, XMODEM-1K, XMODEM-G, YMODEM, and YMODEM-G file transfer protocols. This allows the programmer to run multiple protocol transfers simultaneously while interacting with the user at the keyboard. The Personal Protocol Library for C (PPL4C) is available for $35 plus $3 S&H ($6 S&H overseas). Both the Communications library and the Protocol library can be ordered together for $65. The PPL requires the Personal Protocol Library for C (PCL4C) as described above. EMS4C Users Manual Page 21 8.3 The LZW Data Compression Library for C LZW4C is an implementation of the LZW (Lempel-Ziv-Welch) algorithm for compressing and decompressing data. LZW does particularly well on text files, achieving better than a 50 % compression ratio for many files. The LZW algorithm is considered to be one of the best general purpose algorithms available today. The new high speed modems that employ on-the-fly data compression (such as MNP 5.0 & the V.42 bis international standard) use the LZW algorithm, as well as such well known utility programs such as PKZIP. The LZW Data Compression Library for C is available for $35 plus $3 S&H ($6 S&H overseas). EMS4C Users Manual Page 22