Global MicroComputer Specifications

The table below shows the technical characteristics of some old computers, like the type of CPU unit, RAM memory capacity, ROM capacity which stored the basic firmware or Operating system, and dedicated Video RAM for graphics display.

The latter was quite important, because the more video RAM (vram) there was, the better the graphics were.

In the early 80s, a personal computer that could use 16kb of vram was a very good machine!

The ROM is now a bit like the Flash we have on our phones, except that the firmware or OS was not updated as easily, as it was not erasable.

If you find any inaccuracies, or if you have any questions about retro computing, please leave me a message below.

Brand/Model Country Year Units Sold CPU Coprocessors RAM ROM VRAM
Commodore VIC20 US Sept. 1980 2.5 million MOS 6502 @ 1.02Mhz - 4 KB 20 KB 1 KB
Sinclair ZX81 UK March 1981 +1 million
Zilog Z80 @ 3.25Mhz - 1 KB (up to 64KB) 8 KB
TI 99/4A US June 1981 2.8 million
TMS9900 @ 3Mhz - 256 bytes 16bits (up to 32KB) 26 KB 16 KB
Commodore 64 US Sept 1982 22 million
MoS 6510 @ 0.985 MHz - 64 KB 16 KB (20KB for the 64C) up to 20KB of RAM used
Apple IIe US Jan 1983
MoS 65c02 @ 1Mhz - 64KB 16KB up to 16KB of RAM used
Tandy/RS TRS 80 CoCo II US Sept 1983
Motorola 6809E @ 0.895 MHz
16 KB 16 KB
Micronique Hector HRX FR Aug 1983
Zilog Z80A @ 5Mhz - 64KB 16KB
Atari 800 XL US Dec 1983
MoS 6502C @ 1.77 MHz - 64KB 24KB up to 8KB of RAM used
ORIC Atmos UK 1984
MoS 6502A @ 1 MHz
48 KB 16 KB 8 KB of RAM used
Thomson MO5
FR
1984

Motorola 6809e @ 1Mhz
-
32 KB
16 KB

Philips VG8020 msx NL 1984
Zilog Z80 @ 3.58MHz - 64 KB 32 KB 16 KB
VTECH Laser 310 HK 1984
Zilog Z80 @ 3.58MHz - 16 KB 16 KB 2 KB
Exelvision EXL100
FR
1984

TI tms 7041 + tms 7020 @ 4.91 MHz -
32 KB up to 290
4 KB

Commodore 128 US 1985 4 million
MOS 8502 @ 1.97/0.985MHz
+ Zilog Z80A @ 4Mhz
- 128 KB 64 KB 16KB + up to 20KB of RAM used
Thomson MO6 FR 1986
Motorola 6809e @ 1MHz - 128 KB 64 KB 16 KB of RAM used
Sinclair ZX Spectrum 2+ UK 1987 . Zilog Z80A @ 3.54Mhz - 128 KB 32 KB 7 KB of RAM used
Amstrad 6128 plus UK 1987
Zilog Z80A @ 4MHz - 128 KB 128 KB (64 KB used by a demo game!) 16 KB of RAM used
Atari 520 STf US 1987
Motorola 68000 @ 8MHz - 512 KB 192 KB 32 KB of RAM used
Macintosh II
US
1987
 
Motorola 68020 @ 16Mhz
68881 FPU
1 MB
256 KB
external video card (300 KB typ.)
Commodore Amiga 600 US march 1992 a500+;August 1990 5 million (all Amigas)
Motorola 68000 @ 7.14MHz - 1 MB 512 KB up to 1 MB of RAM used (2 MB with extension)
Apple Macintosh SE30 US 1991
Motorola 68030 @ 15.77Mhz 68882 FPU 4 MB 256 KB

Books

If you're interested in Retrocomputing, I would also recommend reading the following books. I find very interesting how these computer industry pioneers, with brilliant ideas, made history and begun to earn millions of dollars !

Sound, Graphics, I/O

The table below gives more details about the graphics and sound capabilities of old computers.

Multimedia capabilities started to be much better, around 1985, when the 1st mass produced 16/32 bits computers were introduced. Specialized processors were often in charge of displaying and moving quickly bitmaps for games (BIT BLT column), to ease the task of the main micro-processor.

Brand/Model Text Modes Graphics Modes BIT BLT/Sprites Sound

I/O ports
Commodore VIC20 - 22x23 8 colours - 176x184 16 colours
none 3 voices (square wave), noise and volume

Video composite, 1 Joystick, Cardridge, Tape, Serial, User Port (RS232 compatible)
Sinclair ZX81 - 32x22 B/W - 64x44 B/W
- 256x182 B/W with 16KB RAM expansion
none none

RF video, Expansion slot, Tape
TI 99/4A - 40x24 B/W - 32x24 16 colors
- 256x192 16 colors, 2 colors per 1x8 block
- 64x48 16 colors
32 sprites TMS9919 3 voices, 1 noise

ROM cartridge, tape, Audio/Video output, Joystick, bus expansion
Commodore 64 - 40x25 16 colors - 320x200 16 colors (1 color per 8x8 block)
- 320x200 16 colors (1 color per 1x8 block) - 160x200 16 colors (4 colors per 4x8 block)
- 160x200 16 colors
yes SID 6581: An advanced 3 voices synthetizer

Video composite, Joystick x2, Cardridge, Tape, Serial, User Port (RS232 compatible)
Apple IIe - 40x24
- 80x24 (with 80 columns card)
- 40x48 16 colors
- 280x192 6 colors with constraints
- 560x192 16 colors with constraints
none 1 channel

Composite video, Internal slots *7, Tape, Joystick *2
Radio Shack TRS 80 CoCo II - 32x16 8 colors - 32x16x8 colors
- 64x32x8
- 128x96x2 or 4
- 128x192x2 or 4
- 256x192x2
none 1 voice

Tape, RGB, Joystick x2, Cardridge, Serial RS232
Micronique Hector HRX - 40 x 24 4 colors - 243 x 231 4 colors. 15 colors palette none 1 voice

RGB, Centronics, Cardridge, Joystick * 2
Atari 800 XL up to 40 x 24 5 colors
256 colors palette
- up to 320 x 192 1 color
- up to 160 x 192 4 colors
- up to 80 x 192 16 colors
256 colors palette, flexible video chip (ANTIC)
4 sprites 8x256 1 color, 4 sprites 2x256 1 color, H/V scrolling Atari POKEY, 4 voices

Composite Video, Bus, Cardridge (16KB), Joystick * 2, Tape+Serial Bus
Oric Atmos 40 x 28 8 colors 240 x 200 8 colors with constraints (hard to display more than two colors per line) none 3 voices: AY-3-8912

RBG, RF video, Bus, Printer, Tape
Thomson MO5 - 40 x 24 - 320 x 200 16 colors (1 color per 1x8 block)
none
1 voice (8 bits DAC)

RGB (Scart), Light Pen, Tape Cardridge,  Bus
Philips VG8020 msx 40 x 24 16 colors 256 x 192 16 colors with constraints yes 3 voices: YM-2413

RGB, Centronics, Cardridge *2, Tape, Joystick *2
VTECH Laser 310 - 32 x 16 9 colors - 64 x 32 9 colors
- 128 x 64 8 colors
none beeper, 1 voice

RGB, Tape, Centronics (opt), Expansion bus
Excelvision EXL100
- 80x25
- 320x250 8 colors
?
Vocal synthetizer


IR joystick+keyboard, centronics, bus, RAM ROM ext, tape
Commodore 128 - 40x25 16 colors
- 80x25 16 colors
- 80x50 16 colors
- 640x200 16 colors (1 color per 8x8 block)
- 320x200 16 colors (1 color per 8x8 block)
- 320x200 16 colors (1 color per 1x8 block)
- 160x200 16 colors (4 colors per 4x8 block)
- 160x200 16 colors
yes SID 6581: An advanced 3 voices synthetizer

RGBI, Video composite, Joystick x2, Expansion port, Tape, Serial, User Port (RS232 compatible)
Thomson MO6 - 80 x 24
- 40 x 24
- 160 x 200 16 colors
- 320 x 200 16 colors (1 color per 1x8 block)
- 640 x 200 2 colors
4096 colors palette
none 1 voice (8 bits DAC)

RGB (Scart), Light Pen, Joystick, Mouse, Centronics, Cardridge, Stereo, Bus
ZX Spectrum 2+ - 32x22 8 colors - 256x192 8 colors (1 background/foreground by 8x8 block) no 3 voices: AY-3-8912
+ 1 bit audio


Z80 Bus, Numeric Keyboard, RS232 or Midi Out, Audio, RGB, 2 x Joystick
Amstrad 6128 plus - 40 x 25
- 80 x 25
- 20 x 25
- 160 x 200 16 colors (32 colors with sprites)
- 320 x 200 4 colors (20 colors with sprites)
- 640 x 200 2 colors
27 or 4096 colors palette
16 sprites (16 x 16 15 colors each in any graphics mode, XY x1 x2 x4 magnification), hardware scrolling, horizontal split screen with independent scrolling 3 voices: AY-3-8912 + possibility to stream data without CPU intervention

RGB, Centronics, Z80 Bus, Joystick x 2, 1 Analog Joystick (SUB-D 15), Light gun (RJ-11), Disk unit, Tape, ROM Cardridge (up to 512 KB)
Atari 520 STf - 40 x 25
- 80 x 25
- 320 x 200 16 colors
- 640 x 200 4 colors
- 640 x 400 B/W
512 colors palette
NO (Appeared on the MegaST and STe) 3 voice: YM-2149

RGB, Cardridge, Midi in and out, Centronics, RS232c, Hard Disk, Floppy disk, Joystick, Mouse
Macintosh II

- 640x480 256 colors (external video card)
Depends on video card
Stereo 8 bits


ADB x2, Serial x2, 6 Nubus slots, 2 integrated FD
Amiga 600
- VERY flexible PAL/NTSC chip - up to 320 x 512 from 2 to 64 or 4096 colors - up to 640 x 512 from 2 to 16 colors - up to 1280 x 512 2 or 4 colors - 4096 colors palette. - overscan, dual video output Yes 4 stereo channels 8 bit (28 or 56 Khz sampling rate)

Analog RGB, Composite Video, 2 Stereo Audio RCA, 1 parallel port, PCMCIA T1, 1 internal slot, Mouse/Game port x2, RS-232 (DB-25), External Floppy,
Apple Macintosh SE/30 - 512 x 342 B/W none 1 voice (22Khz / 8 bits DAC)

RS232/422 *2; ADB *2 (keyboard, mouse), Stereo, Floppy disk, SCSI, 68030 Processor Direct Slot

Sound chip specs

Since first micro-processors were not fast enough to handle graphics, sounds, and calculations at the same time, the best old computers were equipped with co-processors dedicated with sound generation.

The AY-3-8910, created in 1978, was one of the most popular of them, and was used in many arcade games, pinball machines, game consoles and 8-bits home computers, like the Amstrad CPC, Oric-1, MSX, Sinclair ZX Spectrum.

Here is some of the most frequently used sound generators found in home computers:

→ AY-3-8912: 3 voices 9 octaves 16 volume levels, 1 noise generator, 10 fixed enveloppe paterns (but with programmable period). It's the same chip as the AY-3-8910, but with less I/O ports.

→ YM-2149: 3 voices 8 octaves 32 volume levels, only 1 waveform (square wave), 1 noise generator, 10 fixed enveloppe paterns. similar to AY-3-8912.

→ SID 6581: 3 oscillators (0-4Khz), 4 waveforms per oscillator (Triangle, Sawtooth, Variable Pulse, Noise), 3 amplitude modulators (8 bits), 3 envelope generators (Full ADSR), ring modulation, programmable filter (low pass, Bandpass,High pass, Notch with variable resonance), one channel can be used as a 12 bits PWM (12 bits digital sound in 1983 !!!).

→ YM-2413: FM synthetizer, 9 poly channel or 6 channels and 5 rythm sounds. Built-in instruments: 15 melody tones, 5 rhythme tones. 1 programmable instrument (ADSR).

→ Atari POKEY: 4 voices of 8-bit pitch-resolution, 4-bit volume-resolution, 8-distortion sound can be produced. 2 voices (1 and 2, and/or 3 and 4) can be combined to make 16-bit pitch-resolution. Also 4-bit volume-only modes can be enabled for digitally sampled sound replay.

Obsolete Microprocessors

I also tried to estimate to power in MIPS of these old processors using the theorical cycles needed for basic machine language instructions.

Brand/Model Year Type Typ. Freq. Registers Imm. Load Mem. Load And Imm. And Incre- ment Imm. Sub- stract Compa- rison Condi- tionnal Jump Stack Push Estimated Power
Zilog Z80 July 1976 8 bits 4-8 Mhz 1 x 8bits
3 x 16bits (or 6 x 8 bits)
2 x 16bits index (double all these numbers if you count shadow registers)
7 (10*) 7 (16*) 4 7 4 7 7 12-7 11* 0.58 MIPS @4Mhz
MoS 6502 1975 8 bits 1-2 Mhz 1 x 8bits**
2 x 8bits index
2 3-4 2 2 2 2 2 2-3 4 0.43 MIPS @1Mhz
Motorola 6809 1977 8 bits 1 Mhz 2 x 8bits (or 1 x 16bits)
2 x 16bits index
2 4 2 2 2 2 2 3 5 0.42 MIPS @1Mhz
TI TMS 9900 June 1976 16 bits 3 Mhz 3 x 16bits
256 x 16bits in fast ext RAM
0.1-0.2 MIPS @3Mhz
Intel 8086/8088 1978 16 bits 8 Mhz 4 x 16bits (or 8 x 8bits)
4 x 16bits index
4 x segment
4 14 3 4 2 4 3 16 8 1.2 MIPS @8Mhz
Motorola 68000 Sept 1979 16/32 bits 8 Mhz 16 x 32bits 4/8 8 4 8 4 4/8 4 10/8 8 1.4 MIPS @8Mhz
*: Using 16 bits values or registers
**: Only one register but fast access to the 1st 256 bytes of memory. So the 6502 was close to having 256 registers
68000: 68000 transistors.

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