ZX Spectrum +3
The +3: built-in disk drive and an Amstrad-made gate array.
Open the ZX Spectrum +3 in Retro Bench- Also
- Spectrum +3 (disk)
- Year
- 1987
- CPU
- Z80A @ 3.5469 MHz
- RAM
- 128 KB (banked, four 41464)
- ROM
- 64 KB (two 32K ROMs, four 16K pages, +3DOS)
- Video
- Gate array: 256 x 192, 8 colors
- Sound
- AY-3-8912 + beeper
- OS
- 128K BASIC, +3DOS
Chips
| Chip | Where | Role |
|---|---|---|
| Z80A CPU | IC2 | Main CPU (8-bit, 40-DIP) |
| Spectrum 128 / +2 / +3 ULA or gate array | IC1 (40077) | Video, memory banking, ports (7K010E-5 on the 128; Amstrad 40056/40077 on later models) |
| AY-3-8912 sound chip | IC11 (AY-3-8912A) | Three-voice programmable sound generator with one 8-bit I/O port |
| 4464 / 41464 DRAM 64K x 4 | IC3-IC6 (64K x 4) | Dynamic RAM, 64K x 4. Main RAM on the BBC Master; reported on later 130XE boards. |
Ports and connectors
- PSU in, DIN 6-pin socket UNVERIFIED
- TV (UHF RF out), TV socket (RF) UNVERIFIED
- TAPE/SOUND, 3.5 mm stereo jack
- RGB/PERITEL, DIN 8-pin 270° socket
- Joystick 1 and 2, DE-9 male (two identical sockets)
- RS232/MIDI, BT-style 6-way socket
- AUX (keypad position), BT-style 6-way socket
- PRINTER (Centronics), Card edge, 17 + 17 contacts
- DISK B: (second drive), Card edge, 17 + 17 contacts
- EXPANSION I/O, Card edge, 27 + 27 contacts, keyway between 4 and 5
Symptoms
- Power lamp not lit
- No picture at all
- Picture garbled, sound present: check ULA 128, Z80A, 4464
- Picture but no sound
- No menu after RESET
- Menu bar will not move, dead keys: check ULA 128
- Test ROM shows only a colored border: check 4464
- Drive A: not ready