NEC PC-8401BD, NEC, 1984 Hardware info by Guru --------------------- This is a portable laptop computer made by NEC in 1984. Main Board ---------- 72404553 PDS-E-0154 NEC-14T MADE IN JAPAN PAT,P-END Sticker: AIA 606 0325 |------------------------------------------------------------| | CMT PRINTER RS232 TEL LINE RES DC_IN | | | | D71051G PWR_SW| | SW1 | | VR2 POWERI | | X1 3.6V_NICAD | |--| LCD BATTL | | BX7307 BEEPER 4P VR1| | X 32.786kHz | |-| Y D1990 VR3 | | | | | | |--SUB-BOARD-ABOVE---| | | | | IC14 | PC817 PC817 | | |SB | | PC817 PC817 | | | | | | | | |CN1 CN2| | | | | IC17 | X3 BX7309A | |-| | | IC20 M6926 | | |--------------------| | | | |--| D70008C D23C1000 KEY | | | |------------------------------------------------------------| Notes: D71051G - NEC D71051G Serial Control Unit (CMOS USART) IC14 - NEC D65002G066 uPD65000-series CMOS Gate Array IC17 - SMOS Systems SLA6140F1G SLA 6000-series CMOS Gate Array CMT - Cassette/Tape Recorder Port TEL/LINE - RJ11 Sockets for Telephone Line In (for use with internal modem) and Telephone Handset Pass-Through PWR_SW - Power On/Off Switch SB - System Bus Connector. This allows connection of a RAM cart, a ROM cart (do any exist?) and various plug-in expansions. Known Expansions: PC-8281A Data Recorder (for storing data on tape/cassette) PC-8405A ROM Cartridge (for what software exactly?) PC-8406A 32kB Battery-Backed RAM Cartridge. This allows total system RAM 64kB + 32kB external RAM for file storage. PC-8407A 128kB Battery-Backed RAM Cartridge. Q: Does this increase system RAM or only battery-backed file/data storage? PC-8431A 3 1/2" Micro Floppy Disk Unit PC-8433A Disk Adapter PC-8441A CRT/Disk Adapter. Provides Monochrome and RGB CRT video outputs with the PC-8433A Disk Adapter. PC-8461A 1200 Baud Modem BX7309A - ROHM custom SIL module. Purpose unknown, possibly keyboard or modem related BX7307 - ROHM BX7307 SIL module. Purpose unknown, possibly reset-related POWERI - Power-related SIL Module BATTL - Connector for 4x C-cell battery power LCD - 16-pin connector for LCD panel flat cable X - SIL Module. Purpose unknown, possibly CMT-related Y - SIL Module. Purpose unknown, possibly RS232-related RES - Fujisoku AP1C 61 Momentary Push Button. This is a manual reset switch. D70008C - NEC D70008C Z80-compatible Microprocessor. This doesn't have higher speed-rated markings so clock input is likely to be 3.9935MHz [7.987/2] D23C1000 - NEC D23C1000 28-pin 128kBx8-bit mask ROM at location IC24. No label present on ROM. Board marked 'MRIO' This contains the system BIOS, CP/M Operating System and some built-in applications including Wordstar. M6926 - OKI M6926 300-Baud Single Chip Modem, compatible with ITU-T V.21. Clock input 3.579545MHz D1990 - NEC uPD1990AC Serial I/O Calender and Clock CMOS LSI. Clock input 32.768kHz IC20 - NEC uPC358C Dual Operational Amplifier 4P - 4-pin connector for battery-low and sleep LEDs that are located on the top right side above the keyboard X1 - 7.987MHz Oscillator X2 - 32.768kHz Crystal X3 - 3.579545MHz Crystal BEEPER - Taiyo Piezo Beeper/Speaker DC_IN - 9V DC Power Input Barrel Jack PC817 - Sharp PC817 Optocoupler VR1 - LCD Contrast Adjustment Potentiometer/Wheel VR2 - Potentiometer for ?. Possibly 5V Adjustment? VR3 - Adjustable Capacitor Potentiometer for RTC 32.768kHz frequency fine tuning PRINTER - DB-25 Parallel Port RS232 - 2x DE-9 Serial Ports KEY - 15-pin connector for keyboard cable SW1 - 2-position switch on bottom of main board. Switching it resets and clears the RAM disk. The switch actually disconnects the RAM from VCC and connects it to GND thus fully draining any charge from the RAMs and setting the contents to be uninitialized. The battery-backed RAM must be formated again to use it. Internal RAM Board ------------------ This plugs into CN1 and CN2 on the main board and provides 64kB RAM. RAM is split between a RAM disk and available memory. 32kB is battery-backed for file/data storage used with the built-in applications and 32kB is for the system. When a RAM expansion cart is plugged in, the system RAM becomes 64kB and data/files are stored on the cart battery-backed RAM. The 32kB RAM expansion can be used in one of 2 ways.... 1) In 32kB mode: Two RAM disks of 32kB each accessible as Drive A: and Drive B: When swapping drives the memory available to the system is conditional on the RAM usage in the bank selected. 2) In 64kB Mode: Drive A: is on the RAM cart (you can store a maximum of 32kB there). However memory is stacked in this mode. The more free space you have on the cart the higher available to the system. If the floppy disk unit or any non-RAM cart is used the RAM expansion cart can't be used since all expansions share the same main board expansion bus connector. None of the known expansions contain any battery-backed RAM and none of the known expansions have a pass-through connector therefore using a RAM expansion cart and also any other bus connector expansion together is not possible. However it is assumed that when using the floppy disk unit the RAM memory map switches to '64kB Mode' and drives A: and B: are changed automatically to the floppy disk unit. PWD-456 D6CA090 7240456 Sticker: 606 0325 |-----------------------| | | |D4364 D4364 D4364 D4364| | | | | |CN1 CN2| | | | | |D4364 D4364 D4364 D4364| | | |-----------------------| Notes: D4364 - NEC uPD4364-20L 8kBx8-bit CMOS Static RAM. Total 64kB system memory with 32kB devoted to battery-backed file storage. However the system memory map changes depending on the type of expansion plugged in. Memory Map for ROM Program Cart Mode: FFFFH ------------------- BIOS 2.5kBytes F600H ------------------- BDOS 3.5kBytes E800H ------------------- TPA 26kBytes 8100H ------------------- ZERO PAGE 256bytes 8000H ------------------- ROM 32kBytes 0000H ------------------- Memory Map for 32kB CP/M Mode: FFFFH ------------------- BIOS 2.5kBytes F600H ------------------- BDOS 3.5kBytes E800H ------------------- AVAILABLE 32kBytes 6800H ------------------- TPA 26kBytes 0100H ------------------- ZERO PAGE 256bytes 0000H ------------------- Memory Map for 64kB CP/M Mode: FFFFH ------------------- BIOS 2.5kBytes F600H ------------------- BDOS 3.5kBytes E800H ------------------- TPA 58kBytes 0100H ------------------- ZERO PAGE 256bytes 0000H ------------------- LCD Panel --------- The LCD panel provides an 80-column x 16-line text display. EPSON P300012000 Sticker: EPSON ECM-A0053-1 663C44 MADE IN JAPAN |------------------------------------------------| |SED1180F SED1180F SED1180F SED1180F SED1190F| | | | | |SED1180F SED1180F SED1180F SED1180F SED1190F| | | | | | | | E-1330 | | 4364 4364 | |------------------------------------------------| Notes: SED1180F - Epson SED1180F 64-dot LCD Segment Column Driver (x8) \ Based on the number of chips and pixel drivers this might SED1190F - Epson SED1190F 64-dot LCD Segment Row Driver (x2) / give a total of 512 x 128 pixels? E-1330F - Epson E-1330F LCD Graphics and Display Controller with built-in 4kB character ROM 4364 - NEC uPD4364-20L 8kBx8-bit CMOS Static RAM Display Memory. Total Video RAM = 16kB Keyboard layout is only slightly non-standard and most of the keys are in the standard position.... |-------------- |-------------------------------------------------------| |REMOVABLE PANEL| SLEEP LED | | FOR BATTERIES | LOW BATTERY LED | |---------------| ^ | | < > | <--arrow keys |STOP ESC F1 F2 F3 F4 F5 \/ | |~ ! @ # $ % ^ & * ( ) _ + INS | |` 1 2 3 4 5 6 7 8 9 0 - = DEL | | { } | |TAB Q W E R T Y U I O P [ ] | | : " | |CTRL CAPS A S D F G H J K L ; ' ENTER | | < > ? | |SHIFT Z X C V B N M , . / SHIFT | | | | | \ S---P---A---C---E ALT NUM | | | | | |-----------------------------------------------------------------------| Notes: Removable panel on top left gives access to a battery bay holding 4x C-cell batteries. Total voltage is 6V. LOW BATTERY LED lights on solid when internal C-cell battery voltage is low. The RAM requires at least 2.0V to retain data so the trigger voltage would typically be ~2.5V (for the RAM) but is likely to be around 4.75V due to the C-cell batteries also powering the whole computer when the AC-DC adapter is not connected. The computer likely will not power up unless it has at least 4.75V at the battery terminals. When the C cell battery power is exhausted the main board will power off and the 3.6V nicad will continue to power the battery-backed RAM and RTC chip. SLEEP LED flashes when in sleep mode. To set sleep mode first set a wake-up time and after that you can trigger standby. The PC will then wake up at the requested time. Everything stops until it wakes up. Outside of standby mode, while on battery power the computer will turn off at a set period of time, anywhere from 1 to 25 minutes. When in sleep mode the LCD is off to save power and the battery powers the whole main board and RAM to keep the running programs alive. When wake-up is activated the computer resumes at the same point it was at before sleep was activated. SHIFT + F-keys 1-5 enable F6-F10 When NUM is locked down the following keys are used as the numpad... M = 0 J = 1 K = 2 L = 3 U = 4 I = 5 O = 6 7,8,9 remain the same **************************************************************************************************/