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Epson EL 4S/33+
Memory -
2MB or 4MB RAM standard on SIMMs;
EL 4S/33+ Components
expandable to 16MB (maximum) using
256KB, 1MB, and 4MB SIMMs; SIMMs
The following diagrams illustrate the outside of the
must be 30-pin, 8-bit or 9-bit, fast-page
EL 4S/33+ system.
mode type with access speed of 70ns or
faster (preferably tin-plated)
ROM 64KB system BIOS and SETUP code
located in EPROM on main system board;
32KB video BIOS located in EPROM on
main system board
Video RAM 256KB DRAM on main system boar
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Epson EL 4S/33+ Keyboard PS/2 compatible keyboard interface built Setup Stored in ROM accessible by pressing into main system board; 6-pin, mini DIN Ctrl Alt S at the MS-DOS prompt Program connector; Num Lock setting selectable through SETUP Physical Characteristics Mouse PS/2 compatible mouse interface built Width 15.6 inches (396 mm) into main system board; 6-pin mini DIN 14.5 inches (368 mm) Depth connector Height 4.1 inches (104 mm) 10-pin game port interface on system Game port board; can c
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Epson EL 4S/33+ Major Subassemblies System Board Components 12/93 Epson EL 4S/33+ - 3
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Epson EL 4S/33+ System board components and connectors Jumper Settings Use J10 with the built-in VGA adapter only. When J10 is ON, 1024 x 768 mode is interlaced and 800 x 600 mode refreshes at 56Hz. When J1O is OFF, 1024 x 768 is non-interlaced and refresh at 60Hz; 800 x 600 refreshes at 72Hz. (VG 460 x 480 refreshes at 60 Hz regardless of the J10 setting) “‘You can use MS-DOS to automatically reassign parallel and serial ports. Check your MS-DOS manual for more information. SIMM Installation Yo
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Epson EL 4S/33+ Hard disk drive types Video Memory The computer comes with 256KB of video memory. You can increase the video memory to 512KB or 1024KB by installing 20-pin, 70ns or 80ns, 44256 DIP (Dual Inline Package) chips. For the memory to work properly, you must install one chip in each socket. Video memory chip configuration * Standard video memory Resolutions and colors Math Coprocessor Upgrade You can enhance your system’s performance for some applications by installing a Cx83S87-33 math
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Epson EL 4S/33+ Standard diskette drive specifications Drive Option Information DMA Assignments Level Assigned device DMA0 Reserved (8-bit) DMA1 Reserved (8-bit) FDD controller (8-bit) DMA3 Reserved (8-bit) Cascade for DMA controller 1 Reserved (16-bit) DMA6 Reserved (16-bit) DMA7 Reserved (16-bit) Hardware Interrupts IRQ no. Function lRQ0 Timer output IRQ1 Keyboard IRQ2 Cascade from IRQ controller 2 IRQ3 Serial port 2 IRQ4 Serial port 1 IRQ5 Parallel port 2 IRQ6 FDD controller 12/93 Epson EL 4-
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Epson EL 4S/33+ System Memory Map System l/O Address Map 000FFFFFFh System BIOS ROM: 64KB Dupliated from 0F0000h 000FF0000h Reserved for system board: 64KB Duplicated from 0E0000h 000FE0000h 16MB (Maximum Extended memory system memory) 1MB 00100000h System BlOS ROM: 64KB Default Shadow RAM duplicated at FF0000h 000F0000h Unused or l/O expansion ROM 160KB Reserved for ROM on I/O adapters 000C8000h VGA BlOS ROM: 32KB Default shadow RAM 000C0000h VGA text (color): 32KB Unused or VGA text (monochrom
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Epson EL 4S/33+ Hard disk drive connector pin assignments (J38) Connector Pin Assignments Parallel port connector pin assignments (CN3) *Active low logic Serial port connector pin assignments (CN4 and CN5) *Active low logic Speaker connector pin assignments (J34) Optional game port connector pin assignments VGA port connector pin assignments (CN2) Optional game port interface pin assignments (J1) Power supply connector pin assignments (CN8) Option card riser board connector pin assignments (S1)
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Epson EL 4S/33+ Option card riser hard connector pin assignments (S1) (continued) SIMM sockets (RAM1, RAM2, RAM3, RAM4) *Active low logic Use only 30-pin, 8-bit or 9-bit, fast-page mode SIMMs (preferably tin-plated) that operate at an access speed of 70ns (nanoseconds) or faster. SIMMs must operate at the same speed. Installation/Support Tips Installing Diskette Drives Make sure that the drive type has been correctly selected in the SETUP program. Installing Hard Disk Drives When installing a ha
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Epson EL 4S/33+ Software Problems Information Reference List When installing a copy-protected software package, first try the installation at high speed. If this does not work Engineering Change Notices properly, select low speed by pressing the Ctrl and Alt None. keys and the - key on the numeric keypad simultaneously. Try loading the program at low speed Technical Information Bulletins and then switching to high speed, if possible. None. When using a software package that uses a key disk as it
