I have five SV 328 main units (one CIB) and two SVI 328 main units (one CIB), six power adapters, six rf modulators, six tape drives SV-904 (one CIB).
type computer
country USA
year 1983
os SV Microsoft Basic 1.0
cpu Zilog Z80 a
speed 3.6 MHz
ram 80 KB
vram 16 KB
rom 32 KB
graphic 256 x 192
colors 16
sound 3 channels, 8 octaves
ports centronics, rs232c, rgb, tape, joystick (2), cartridge
The Spectravideo SV-328 (also known as the SVI-328) is a fascinating piece of computing history. Released in 1983, it holds a special place in the hearts of retro-enthusiasts because it served as the direct architectural predecessor to the MSX standard.
While it isn’t ”officially” an MSX machine, its internal design was so influential that Microsoft and ASCII Corporation used it as the blueprint for the MSX1 specifications.
Technical Specifications
The SV-328 was the ”pro” version of its smaller sibling, the SV-318. While the 318 had a chiclet keyboard and less memory, the 328 featured a full-travel typewriter keyboard with a numeric keypad.
| Feature | Specification |
| CPU | Zilog Z80A running at 3.58 MHz |
| RAM | 64 KB (expandable up to 256 KB) |
| VDP | Texas Instruments TMS9918A |
| Audio | General Instrument AY-3-8910 (3 voices + noise) |
| Operating System | Microsoft BASIC (integrated) |
The MSX Connection
The similarity between the SVI-328 and the MSX1 standard is striking, but they are not compatible out of the box.
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The Hardware: They share the same CPU, Video Display Processor, and Sound Chip.
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The Difference: The memory mapping and the BIOS are different. Because of this, you cannot simply plug an MSX cartridge into an SVI-328 and expect it to work without an adapter or modifications.
Expandability and ”The Super Expansion Box”
Spectravideo went all-in on peripherals. The most iconic accessory was the SV-601 Super Expansion Box. It was a massive external chassis that looked like a piece of hi-fi equipment. It allowed users to add:
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Single or double 5.25″ floppy disk drives.
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RS-232 serial interfaces.
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Additional RAM cards.
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A hard drive controller.
Legacy in the Nordic Countries
The SV-328 was particularly popular in Finland and Sweden. It gained a loyal following before the Commodore 64 completely dominated the market. Many early Finnish programmers got their start on the SVI, and because the hardware was so close to the MSX, many enthusiasts later found it a natural transition to the MSX ecosystem.
Fun Fact: The ”SVI” prefix was adopted because ”SV” was already a trademarked brand in certain regions, leading to the name change to Spectravideo International.
The Spectravideo SV-328 — The Enhanced Spectravideo
The Spectravideo SV-328 was the enhanced version of the SV-318, offering 80 KB of RAM (versus 32 KB), 80-column text mode capability, a full-travel keyboard replacing the SV-318’s more modest keyboard, and additional I/O capabilities. The SV-328 was positioned as the professional or serious user’s Spectravideo — more capable than the SV-318 for business applications and extended programming sessions while sharing the same fundamental architecture. Like the SV-318, the SV-328’s design directly influenced the MSX standard specification.
80-Column Mode
The SV-328’s 80-column text mode was a significant practical advantage for business users — allowing full-width documents to be displayed without horizontal scrolling, making word processing and spreadsheet applications genuinely usable. Combined with the 80 KB of RAM and full-travel keyboard, the SV-328 was a credible business computer at a time when most home computers were being dismissed as toys by corporate users. This professional capability was part of Spectravideo’s positioning as a more serious alternative to the gaming-focused ZX Spectrum and Commodore 64.