Adding Drivetec Drives to a Nascom

by Michael Hendry

Introduction

Like many readers of Scorpio News, I found much of interest in the surplus offers in the last issue but one (Vol. 1 Issue 3), and contacted Scorpio at once about what was to me the most tempting, the offer of two Drivetec drives (3.3 Mbytes each, unformatted) at £50 the pair. Although many of the other bargains had gone by the time I phoned, I was in time to order these and also an old-style Gemini two-drive enclosure with power supply, which would enclose my two new half-height drives and my existing 80 track Toshiba drives.

At that time my system comprised:–

• NAS­COM 2 board
• Home-brew 128k memory board with 1M ramdisk
• MAP80 VFC card
• Twin 800k Toshiba drives
• Various operating systems:– NASDOS, CP/M 2.2, CP/M 3.1

and my main database included:–

• Over 1M of data files, with associated index files.

As my data files spread over more than one floppy, I was forced to split the whole database into two logical halves, each stored on one disk, and this meant that both my drives would be occupied with data after I had copied the main program files on to ramdisk. This implied several changes of disk after booting up for the day, and foolproofing became more and more difficult with the increasing number of disk changes.

The plan became:–

Drive A (QDDS) Main program disk
Drive B (QDDS) Supplementary program disk
Drive C (Drivetec) Database disk and backup source
Drive D (Drivetec) Auxiliary data, and backup destination
Drive M Temporary disk