Timex Sinclair 1500

The Timex Sinclair 1500 placed ZX81-compatible electronics and 16KB of RAM inside a silver-grey case derived from the ZX Spectrum. Its rubber-key keyboard offered tactile movement while retaining the single-keyword entry system of the earlier Timex Sinclair 1000.

The machine corrected several practical weaknesses of its predecessor, including RAM-pack dependence and display interference, but reached stores after inexpensive colour computers had transformed the American market. Its monochrome capabilities made it a difficult product to sell despite the low price.

Notable Features

• 16KB RAM was built in and could be expanded to 32KB with a compatible pack.
• Spectrum-derived enclosure replaced the flat membrane keyboard with moving rubber keys.
• Redesigned NCR logic reduced heat and improved display quality.

Historical Significance

• A distinctive transitional model between Timex's ZX81-derived and Spectrum-derived computers.
• Manufactured by Timex's Portuguese operation for the North American market.

Collector’s Notes

• The altered expansion connector makes some third-party ZX81 accessories mechanically or electrically incompatible.
• Its silver-grey case and TS1000-style key legends distinguish it from a normal ZX Spectrum.

Specifications

Technical Information
Name	Timex Sinclair 1500
Manufacturer	Timex
Launched	Thursday, September 1, 1983
Launch Price	$79.95
Country	United States
CPU	Zilog Z80A at 3.5 MHz
Units Sold
Operating System	Sinclair BASIC
I/O	RF television, cassette EAR/MIC, power and modified rear expansion bus
Keyboard	Integrated 40-key moving rubber keyboard
Storage	External cassette recorder; optional TS1510 cartridge player
Sound	BASIC BEEP through television speaker
Graphics	64 x 48 block graphics
Display	32 x 24 monochrome characters
ROM	8KB containing Sinclair BASIC
RAM	16KB; expandable to 32KB
CPU Speed	3.25 MHz