Disk System Summary
Over the years a number of disk and operating systems became available for 80-BUS computers. It can get confusing as to what went where. This table hopes to clarify the situation to some degree, but is probably not totally accurate.
| Manufacturer/ Part | Controller Card | Controller | Drive Type | Operating System | Boot ROM | Format T/S/len |
| Airamco - Never taken into production | Unknown | Unknown | Unknown | CP/M ? | Unknown | Unknown |
| Comp | Unknown | Unknown | Unknown | CP/M ? | Unknown | Unknown |
| Henry's Radio (kit) - Henelec | Connected to Nascom parallel port | WD1771 | Pertec FD250Pertec FD514 (8") | D-DOS | D-DOS / FDC S/W | 35*18*128 - Double Sided |
| Q-DOS-(MicroPower) | ? | |||||
| POLYDOS 1 | POLYDOS ROM | |||||
| DCS-DOS | DCS-DOS | |||||
| Gemini GM805 (Ready build as above) | Connected to Nascom parallel port | WD1771 | Pertec FD250 | CP/M 1.4 or later CP/M 2.2 | CBIOS-S / FDC S/W | 35*10*512 - Double Sided |
| Pertec FD514 (8") | ||||||
| Lucas / Nascom | Lucas FDC | WD1793 | TEAC FD-50E or FD-55E or FD-55F | NAS-DOS | NAS-DOS | 77*16*256 Single & Double Sided (NAS-DOS) |
| DCS-DOS II | DCS-DOS II | |||||
| CP/M 2.2 | Nascom Boot ROM | 77*10*512 Single & Double Sided (CP/M) | ||||
| POLYDOS 3 | POLYDOS ROM | |||||
| Gemini GM809 / GM815 | GM809 | WD1797 | Pertec FD250 | CP/M 2.2 | SIMON | 35*10*512 - Double Sided |
| POLYDOS 2 | POLYDOS ROM | |||||
| Gemini GM829 | GM829 | WD1797 | Pertec FD250 or Winchester or Micropolis 1015F5/6 | CP/M 2.2 | SIMON / RP/M | Various |
| POLYDOS 4 | POLYDOS ROM |
| Manufacturer | Model | Height | Tracks | Tracks | Size | Comment |
| Pertec | Pertec FD250 | Full | 48 tpi | DS/DD | 400K | SD on Henelec controller |
| Teac | FD-55B | Half | 96 tpi | DS/DD | 400K | |
| Teac | FD-50E | Full | 96 tpi | SS/QD | 400K | |
| Teac | FD-55E | Half | 96 tpi | SS/QD | 400K | |
| Teac | FD-55F | Half | 96 tpi | DS/QD | 800K | |
| Teac | FD-35F | - | - | DS | 800K | 3.5 inch unit |
| Micropolis | 1115-4 | Full | 96 tpi | DS/QD | 800K | |
| Micropolis | 1015-5 | Full | 96 tpi | SS/QD | 400K | |
| Micropolis | 1015-6 | Full | 96 tpi | DS/QD | 800K |
| Product Code | Hardware | Drive Type |
| GM805 | Dual Drive - 800K, Dual Sided | Pertec FD250 |
| GM815 | Dual Drive - 800K, Dual Sided | Pertec FD250 |
| GM825-1S | Single Drive, 400K, Single Sided | Micropolis 1015F5 |
| GM825-2S | Dual Drive - 800K, Single Sided | Micropolis 1015F5 |
| GM825-1D | Single Drive, 400K, Dual Sided | Micropolis 1015F6 |
| GM825-2D | Dual Drive - 800K, Dual Sided | Micropolis 1015F6 |
| GM835 | 5.4Mb Winchester Sub-System | MiniScribe unit |
| GM835/10 | 10Mb Winchester Sub-System | MiniScribe unit |
Both Gemini and Lucas / Nascom supported the SASI interface, however they used ST506 based hard drives. This was achieved by the use of a third party controller card, usually a Xebec S1410A. However it is known that Gemini also used an Adaptec unit (ACB4000A). These controller cards operated by plugging into a connector on the floppy controller in the system. For Gemini this was either a GM829 or GM849. For Nascom / Lucas there was no available controller card with the necessary port. This was solved by the clever use of the MAP-80 MPI card. This card could be configured to look like either a GM829 or the Nascom / Lucas controller. However, since it had a connector for a hard drive controller, it could be used to replace the original Nascom / Lucas FDC and to add the required interface at the same time.
| Drive Size | Comment | Drive Type |
| 5MB Hard Disk | Nascom / Lucas standard hard drive | Rodime RO201 |
| 10MB Hard Disk | Nascom / Lucas standard hard drive | Rodime RO202 |
| 15MB Hard Disk | Nascom / Lucas standard hard drive | Rodime RO203 |
| 20MB Hard Disk | Nascom / Lucas standard hard drive | Rodime RO204 |
| 5MB Hard Disk | Gemini standard hard drive | Unknown |
| 10MB Hard Disk | Gemini standard hard drive | MiniScribe 3212 MFM DR |
| 10MB Hard Disk | Gemini standard hard drive- 3.5 inch | Rodime RO 352 |
| 15MB Hard Disk | Gemini standard hard drive | Unknown |
| 20MB Hard Disk | Gemini standard hard drive | Unknown |
| 20MB Hard Disk | Gemini standard hard drive - Half height | MiniScribe 3425 |
| 20MB Hard Disk | Gemini standard hard drive - Half height, 3.5 inch | MiniScribe 8425 |
| Product Code | Software |
| GM512 | CP/M for Multiboard & GM815 |
| GM532 | CP/M for Multiboard & GM815 |
| GM513 | CP/M for Nascom & GM809 / GM815 |
| GM556 | CP/M for Nascom & GM809 / GM815 |
| GM515 | POLYDOS 1 for Nascom & GM805 |
| GM516 | POLYDOS 2 for Nascom & GM815 |
| GM533 | POLYDOS 3 for Nascom & Lucas |
| GM534 | POLYDOS 4 for Nascom & GM825 |