Timex Sinclair 1000 (ZX81)

Manufacturer Timex/Sinclair
Model TIMEX Sinclair 1000 - Model M330
Serial Number P717592 HO
Processor / Clock Speed Z80A / 3.25 Mhz
RAM Base / RAM Maximum 1K / 16K
Storage Audio Tape
Operating System ROM BASIC
Display / Resolution RF Modulated / 22x32 text chars, or 44x64 pixel graphics
Expansion Cartridge Port

Commentary: This small Z-80 based computer was sold in several forms in the early 1980's. The non-tactile membrane keyboard was a serious detriment to confortable usage. Also, the keyboard is strangely configured as well. This particular model is a later generation of this design (following the ZX-80 and ZX-81), and was relatively inexpensive.

Full view of the system.
A closeup of the tiny membrane keyboard with multifunction keys, allowing the entry of BASIC commands, and graphics symbols. Upper case only!
The manual. Has a nicely paced introduction to programming in BASIC, and include terse appendixes dealing with Z80 assembly programming, and the system internal memory map.
The very unexciting boot screen is almost completely blank! The inverse video "K" is the cursor!
A small division benchmark. This 10000 iteration loop took 1m 29s. The "FAST" instruction disables video updates to allow faster computation. The screen is blank until the program completes.
Side with connectors for RF TV output, data audio input, data audio output, power.
Back with expansion connector. See memory module below.
The bottom, also showing the serial number. Note that this unit is built in Portugal!
1016K Memory expansion module (16K RAM)
System with expansion plugged in.
The motherboard.