Sinclair ZX Spectrum 128 Service Manual

Sinclair ZX Spectrum Service Manual
Spectrum For Everyone https://spectrumforeveryone.com/
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5 PARTS LIST
Introduction
Notes to Table 5.4
Spectrum 128 PCB Component Layout (Editor’s note: missing in available documentation)
Keypad PCB Component Layout (Editor’s note: missing in available documentation)
5.1 INTRODUCTION
Parts lists for the SPECTRUM 128 are provided in table form; one for the case assembly (Table 5.3), one
for the main PCB assembly (Table 5.4) and another for the keypad PCB assembly (Table 5.5). PCB layout
diagrams are given in figures 5.1 and 5.2; the notes to be found in Table 5.4 are explained below.
5.2 NOTES TO TABLE 5.4
1. All RAM chips should have 150ns access time and 128 row refresh. This includes parts from the
following manufacturers: Hitachi, Intel, Mitsubishi, Mostek, Motorola, NEC, OKI, Panasonic, Toshiba
and National.
2. If TR3 is of type KSC839, resistor R24 should be 15K.
3. Provision has been made on the PCB for a 2 to 22pF film dielectric trimmer should the need arise.
4. The ROM should be pin compatible with a 27256 EPROM and have an address access time of less
than 400ns. The output enable access time should be less than 250ns.
5. The crystal is series resonant with 20pm and accurate to 10ppm absolute, +/- 10ppm at 20 to 60°C,
+/- 5ppm per year.
6. If preferred, the 20uF capacitor used for C124 may be split into two parallel capacitors of 10pF +/-
2% in the positions C124 and C130.
7. For FTZ (German) version only.
8. 6.0MHz version (type no?) for use in the UK; 5.5MHz version (type no?) for use in most other
European countries.

Sinclair ZX Spectrum 128 Specifications

General

Brand	Sinclair
Model	ZX Spectrum 128
Category	Desktop
Language	English