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Document ID: DJON-3G6K2H |
Aptiva-PS/1 - Why do I still get "Insufficient Memory" messages after adding memory?
Applicable to: United States
Insufficient memory messages normally occur because there is not enough conventional memory available for programs. Although your system may have 2MB or more of total memory installed, only 640 KB of memory is directly accessible to DOS. This 640 KB block is called conventional memory. The next 384K of memory is the upper memory area and is used by video adapters, network hardware, ROM BIOS and other memory mapped hardware. Certain device drivers and programs can also be stored into the upper memory area by an upper memory manager (like EMM386.EXE in your CONFIG.SYS file). By loading programs into upper memory, more of your conventional memory is free for your applications. Conventional memory and the upper memory area comprise the first megabyte (1024K) of your total memory.
The memory area above one megabyte is called extended memory and cannot be accessed by standard programs running under DOS in real mode. When a program runs in real mode as opposed to protected mode, it is processing as a fast 8086-based computer. On an 80386-based machine or higher, there are programs (Windows) that can switch your computer to protected mode and access your computer's extended memory. Windows is called a DOS-extender program and can store data or inactive code into extended memory. DOS cannot do this.
When you add additional memory to your PS/1 or Aptiva, you increase the capacity of your extended memory and not your conventional memory. This increase in extended memory is especially beneficial to programs like Windows and other DOS-extender programs that run more efficiently when they have access to a large extended memory area. However, adding extended memory in any amount will NOT increase the availability of conventional memory. Conventional memory is fixed at 640K but can be maximized by moving as many of your system programs, TSR's, etc., into upper memory as possible thereby freeing conventional memory for your applications.
To free up conventional memory, first try to remove any unnecessary TSRs or device drivers that are loading into memory at boot-up. This can be done by modifying your CONFIG.SYS or AUTOEXEC.BAT files. You might also consider upgrading to a version of DOS that includes memory manager software like RamBoost for IBM PC DOS 7 and Memmaker for MS-DOS 6.22. In addition, you can purchase memory management software such as QEMM, 386 Max, etc., which will allow you to load DOS, device drivers, and TSRs high, as well as manage the upper memory addresses above 640 KB.
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Search Keywords |
DOS | |
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Hint Category |
Memory, DOS/Windows 3.x | |
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Date Created |
15-04-97 | |
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Last Updated |
23-03-99 | |
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Revision Date |
23-03-2000 | |
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Brand |
IBM Aptiva | |
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Product Family |
Aptiva, PS/1 | |
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Machine Type |
2144, 2168, 2011, 2121, 2123, 2133, 2155 | |
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Model |
2R5; 2R7; 2R8; M30; M35; M50; 2R6; 4R7; 4R8; M40; M54; M58; 3R0; 3R8; M60; M70; 1R2; 66P; 67P; 86P; OR8; 1R1; 1R3; 1R5; 22P; 24P; 25P; 27P; 29P; 63P; 67P; 82P; 83P; OR6; OR7; OR9; 1R0; 1R1; 26P; 62P; 2R0; P30; C01; C34; M01; NEA; T35; U35; A62; A82; A94; B82; C42; C92; G42; M82; S92; 081; 087; 131; 137; K37; N31; N81; 11E; 13T; 14C; 16E; 17A; 18A; 18T; 19C; 21C; 23C; 28A; 46M; 51D; D50; G11; G13; G43; G46; G46; G49; G49; G50; G53; M40; M40; M46; M46; P11; P13; P43; P50; P53; R04; R05; R06; R09; R38; R42; R43; R44; R84; R86; R87; RO3; S11; S13; S43; S45; S45; S47; S47; S48; S48; S50; S53; W11; W13; W42; W42; W43; W45; W45; W50; W53; 20E; 22T; 24C; 24M; 28V; 39E; 41T; 43C; 45V; 48E; 50T; 52C; 55V; 72E; 74T; 76C; 78C; 79C; 81A; 82E; 84T; 86C; 87C; CC1; D53; G14; G44; G52; G54; G72; G76; G78; G82; NM1; P14; P44; P57; P71; P74; P76; P78; P84; R14; R15; R16; R17; R18; R51; R52; R57; R58; R62; R63; R67; R71; R89; R93; R96; R97; S14; S44; S50; S54; S70; S75; S76; S78; S80; W14; W44; W48; W54; W67; W76; W77; W78; Z33; 28V; 31E; 33T; 37C; 38C; 51E; 54T; 56C; 57C; 88V; BB1; G57; G87; OR1; OR3; OR4; OR5; P89; R28; R29; R31; R74; R78; R82; R98; S55; S85; SR1; US1; W52; W82; 2R3; S15 | |
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TypeModel |
2011C01 | |
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