ArVid
ArVid was a data backup solution using a VHS tape as a storage medium. It was very popular in Russia and the rest of the former USSR in the mid-1990s.
It was produced in Zelenograd, Russia by PO KSI.
Features
- Using low-cost VHS tapes and recording units for data backup.
- High reliability
- Hamming code error correction
- Easy data copying between two VHS units
Disadvantages
- Inefficient tape capacity usage
- Poor software support
Operation
Device may operate in two modes: low data rate at 200 KB/s and high data rate at 325 KB/s. The original, lower recording speed was retained as a user option because not all VHS recorders of the time offered sufficient recording quality to reliably support the higher speed.
An E-180 video tape is able to hold 2 GB of uncompressed data at the lower rate, more than sufficient for most PC hard drives of the time. This can be shown by calculating 200 KB/s × 60 s/min × 60 min/h × 3 h = 2.06 GB, which also leaves a few minutes spare for header and synchronisation space.
Note that it is unclear here whether "200 kbyte" means or ; the above calculation assumes the latter, but the former still produces a capacity of 2.01 GB, providing 2.00 GB of capacity in a little under 2 hours and 59 minutes. Similarly, this means that an E240 4-hour tape, using the higher data rate, would be capable of storing between 4.35 and 4.46 GB, approximately equivalent to a standard single-layer recordable DVD.
Models
- ArVid 1010, 100 kbyte/s, 4 kbyte RAM, was first of ArVid devices. Its production started in 1992.
- ArVid 1020, 200 kbyte/s, no RAM, was a successor to ArVid 1010 using more advanced integrated circuitry.
- ArVid 1030/1031, 200 kbyte/s, 64 kbyte RAM, had better internal design, less power consumption, was smaller in size and was made using Complex [programmable logic device|CPLD]. It allowed automatic switching to a TV set when device was not in use.
- ArVid 1051/1052, 325 kbyte/s, 128/512 kbyte RAM