Editing ZX81 (section)

=== Comparisons with other computing devices ===
The following table provides a comparison between the capabilities of the ZX81 and various other competing [[microcomputer]]s that were available in June 1981, about the time that the first ZX81 orders were delivered. The prices given are as of June 1981 from Your Computer UK.
{{sort-under}}
{| class="wikitable sortable sort-under" style="font-size:80%; margin:1em auto 1em auto;"
|-
! scope="col" | Device
! scope="col" | RAM<br/>stan&shy;dard
! scope="col" | Expand&shy;able to
! scope="col" | CPU
! scope="col" | Keyboard
! scope="col" | BASIC
! scope="col" | Sale price
! scope="col" | Number of<br />colours
! scope="col" | Maximum<br />resolution
! scope="col" | Sound
|-
| [[Apple II Plus]]
| 16&nbsp;KB
| 48&nbsp;KB
| [[MOS Technology 6502]] @ 1&nbsp;MHz (8-bit)
| Typewriter
| Integer only
| £549
| 16
| 280 × 192 pixels
| beeper
|-
| [[Atari 8-bit computers|Atari 400]]
| 8&nbsp;KB
| 48&nbsp;KB
| [[MOS Technology 6502]] @ 1.78&nbsp;MHz
| Membrane
| extra
| £289
| 256
| 320 × 192 pixels
| 4 voice
|-
| [[Commodore PET|PET]]
| 16&nbsp;KB
| 40&nbsp;KB
| [[MOS Technology 6502]] @ 1&nbsp;MHz
| Typewriter
| MS Level I
| £399
| Monochrome
| 320 × 200 text only
| beeper
|-
| [[VIC-20]]
| 5 KB
| 32 KB
| [[MOS Technology 6502]] @ 1.02&nbsp;MHz
| Typewriter
| MS Level I
| £189
| 8
| 176 × 184 pixels
| 4 voice
|-
| [[Video Genie]]
| 16&nbsp;KB
| 48&nbsp;KB
| [[Zilog Z80]] @ 1.76&nbsp;MHz
| Typewriter
| MS Level II
| £279
| Monochrome
| 128 × 48 block
| beeper
|-
| [[Compukit UK101|Compukit 101]]
| 1&nbsp;KB
| 48&nbsp;KB
| [[MOS Technology 6502]] @ 1&nbsp;MHz
| Typewriter
| MS Level II
| £149/£199 assembled
| Monochrome
| 128 × 48 block
| extra
|-
| [[TRS-80|TRS-80 Model I]]
| 4&nbsp;KB
| 48&nbsp;KB
| [[Zilog Z80]] @ 1.78&nbsp;MHz (8-bit)
| Typewriter
| Restricted
| £399
| Monochrome
| 128 × 48 block
| extra
|-
| [[Acorn Atom]]
| 2&nbsp;KB
| 12&nbsp;KB
| [[MOS Technology 6502]] @ 1&nbsp;MHz
| Typewriter
| TinyBASIC hybrid
| £140/£173 assembled
| 8
| 256 × 192 mono, 64 × 64 colour
| beeper
|-
| [[Tangerine Microtan 65|MicroTan]]
| 1&nbsp;KB
| 48&nbsp;KB
| [[MOS Technology 6502]] @ 0.75&nbsp;MHz
| extra
| extra
| £65/£99 assembled
| Monochrome
| 128 × 48 block
| extra
|-
| [[TI-99/4A]]
| 16&nbsp;KB
| 48&nbsp;KB
| [[Texas Instruments TMS9900|TI TMS9900]] @ 3.0&nbsp;MHz (16-bit)
| Typewriter
| Restricted
| £399
| 16
| 256 × 192 pixels
| 3 voices and white noise
|- style="color:green; font-weight:bold;"
| ZX81 / TS1000
| 1&nbsp;KB / 2&nbsp;KB
| 32&nbsp;KB
| Zilog or NEC Z80 @ 3.25&nbsp;MHz (8-bit)
| Membrane
| MS Level II equiv.
| £49/£69 assembled
| Monochrome
| 64 × 48 block
| No
|}

{{smalldiv|1=
[[Nota bene|N.B.]]: [[Commodore PET]] includes monitor and cassette recorder.  The Video Genie includes a built-in cassette recorder.  The Compukit 101 is an [[Ohio Scientific]] SuperBoard made under licence in Britain.  Compukit 101 and MicroTan are kit computers and are not supplied with a case.

The [[Atari 400]] and [[TRS-80]] model I were officially only expandable to 16&nbsp;KB, but expansion to 48&nbsp;KB was available from third-party suppliers.

The ZX81 and the other systems referred to as having "block" graphics have a resolution of 256&nbsp;× 192 pixels, there are 32 columns&nbsp;× 22 rows of text and graphics can be addressed in quarter character blocks.
}}