Lucas Nascom Small Lynx Electronics Gemini Small

Disk System Summary

Description

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

Floppy Disk Drives Used

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  

Gemini Disk Units

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

Winchester / SASI / ST506 Based Hard Drives

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

Gemini Disk Operating Systems

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

 

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