Two types of magnetic disk units were developed as the MODEL-G Series. They had the following specifications, and were designed for use as the main memory unit of systems such as the OKIMINITAC.
| MODEL-G-201 | MODEL-G-601 | ||
|---|---|---|---|
| Number of tracks | For main memory | 20 | 60 |
| For synch | 2 | 2 | |
| Recording system | Return to zero | Return to zero | |
| Capacity per track | Approx. 1,000bit | Approx. 1,000bit | |
| Total main memory capacity | Approx. 20,000bit | Approx. 60,000bit | |
| Average delay time | 20/17ms | 20/17ms | |
| S/N | 20db Min. | 20db Min. | |
| Write current | 200mA | 200mA | |
| Output voltage | 60mV-pp | 60mV-pp | |
| Type | Vertical | Vertical | |
| Rotation speed | Approx. 1500/1800rpm | Approx. 1500/1800rpm | |
| Working power supply voltage | 80-110V | 80-110V | |
| Working power supply frequency | 50/60 c/s | 50/60 c/s | |
| External dimensions | D190×W190×H300 | D210×W310×H395 | |
| Weight | Approx. 12kg | Approx. 28kg | |
