Description

Hardware

The Spectravideo SVI-707 is a double-sided 320kB 5.25" floppy disk drive with integrated interface that is meant to attach with a 50-pin ribbon cable directly to the expansion bus port on the back of the SVI-728 or another MSX with polarizing key at center.

The power supply is the same as for the SVI-728. The floppy drive case is white and the power supply is separate but the power button is at the backside of the drive. The floppy disk interface is located in the drive casing below the actual floppy drive.

When powered on this interface starts with an CP/M boot ROM. If the CP/M disk is not found, a load failure sets a one bit register to enable the standard MSX interface ROM with version 1 of the Disk BASIC instructions and resets. The system will then start Disk BASIC or MSX-DOS if a MSX-DOS system disk is present..

This drive is unusual in various ways:

The drive is advertised as having a capacity of 320kB which is less then the 360kB you can typically expect from such a drive type. And indeed formatting a disk either from Disk-BASIC or MSX-DOS produces a disk with just 320kB capacity. However the drive is capable of handling 360kB formatted disks just fine, the built-in format routine just cannot format a disk larger than 320kB.
- 80 track's multiplied with 512bytes and 8 sectors gives 327680
- 80 track's multiplied with 512bytes and 9 sectors gives 368640
In CP/M mode it is able to work with disks from other non-MSX systems, such as the SVI-3x8, Osborne 1, Kaypro II, Bondwell 12, 14 and 16 computer systems.

Spectravideo also sold the SVI-213 connector adapter that could be used to connect the drive to any standard MSX cartridge slot. When using the SVI-707 with another MSX systems, you can only use CP/M if you have 64kB of RAM.

Help needed

It is unclear why, but at least with the emulated SVI-707 in openMSX, using the SVI-707 on other MSX models then the intended SVI-728 is more miss then hit. Have a look at this forum thread. for more details.

Brand	Spectravideo
Type	SVI-707
Year	1985
Region	Europe
Official price	FR: 3,990 F IT: L. 1,082,060 NL: ƒ 1,199 UK: £345.36
Package content	SVI-707 drive with integrated interface CP/M 2.23 (release 1.20 or 1.30) disk MSX-DOS 1.07 disk, AC adapter (SVI-201)
Emulation	ROM dumped and emulated