Amstrad NC100 Surgical Guide
A Surgical Guide To The Amstrad Notepad Computer is a community teardown and hardware reference for the Amstrad NC100 Notepad, written by Hans-Jürgen Böhling of Düsseldorf. It is not an Amstrad publication. The hosted PDF has 14 pages and a text layer; it was made in 2023 from a wiki page that reproduced Böhling's guide, and its first line credits his original document.
Contents
[edit | edit source]The guide's sections, in order:
- What the Notepad is, and how the NC150 and NC200 differ
- Specifications of the NC100
- How to read the firmware version number
- PCMCIA memory cards
- How to open the NC100
- What is inside: the main board and a table of every IC
- Simplified block diagram and power supply block diagram
- Pinouts and descriptions of the main ICs: CPU, custom chip, firmware EPROM, SRAM, memory card slot, real-time clock, UART and RS-232 driver
- RS-232 connector pinout
What it covers
[edit | edit source]The specification gives a Z80-compatible CMOS processor at 4.606 MHz, 64K of RAM, 256K of firmware (word processor, address book, diary, calculator, terminal program and BBC BASIC), a 480 × 64 pixel display showing 80 × 8 characters, and a PCMCIA/JEIDA Type I slot for SRAM cards of up to 1 MB at 5 V. The NC100 runs on four AA cells or an AC adapter, with a CR2032 3 V lithium cell as memory backup, and draws 40–60 mA. It measures 295 × 210 × 22 mm and weighs 930 g. Flash memory cards are not suitable.
Böhling's board is marked Amstrad plc 4500-001P-1. His IC table:
| IC | Part | Function |
|---|---|---|
| IC301 | Zilog Z84C0006FEC | Z80-compatible CPU, 6 MHz rated |
| IC302 | NEC µPD65034 | Custom ASIC: clocks, keyboard, printer and LCD interface, memory management, PCMCIA interface, sound |
| IC303 | NEC µPD27C2001 | 256K × 8 firmware EPROM (the only through-hole IC, under a cover on the underside) |
| IC304, IC305 | NEC µPD43257A | 32K × 8 SRAM |
| IC306 | – | PCMCIA/JEIDA memory card slot |
| IC307 | Toshiba TC8521 | Real-time clock |
| IC308 | NEC µPD71051 | UART |
| IC309 | NEC µPD4711 | RS-232 driver |
| IC310 | 74HC00 | Not fitted; used only with 43256 RAMs |
| IC311, IC314 | 4584 | Hex Schmitt trigger |
| IC312 | LM339 | Comparator for battery level detection |
| IC313 | 4013 | Dual D flip-flop |
The guide also explains the zero-ohm links beside IC303 that select larger EPROM types (27C4001, 23C2001, 23C4001, 23C8001), and notes that the RTC and SRAM run from the lithium-backed 5 V rail.
What this document does not contain
[edit | edit source]- A parts list or values for the resistors and capacitors.
- A circuit diagram; the block diagrams show function only.
- Fault-finding procedures.
- The sg-nc100.zip archive its first line refers to.
Pages that cite this document
[edit | edit source]- Battery Refurbishment – NC100 batteries
Download: Amstrad NC100 Surgical Guide.pdf