A&J Micro Drive

1050 East Duane Ave., Suite I, Sunnyvale, CA 94086

Owner(s): Jim Howell

A&J Micro Drive was a spin-off of Exatron, the company that manufactured and marketed the Exatron Stringy Floppy (ESF). The Exatron Stringy Floppy was a continuous loop tape cartridge (“wafer”) that had some advantages over traditional cassette tapes.

Exatron also manufactured the tape drive mechanism and sold it via mail order to home computer owners. The first ESF drives were made for the TRS-80 Model I. Wafers were available in several lengths, from 5 feet (which could store 4K of data) to 75 feet (up to 64K).

By 1983, Exatron needed additional capital to improve the overall performance and quality of the wafer drives and wafers. With new investors came the name change to Entrepo (a word close to the French word for warehouse). Exatron focused on large OEM accounts and Jim Howell, son of the Exatron founder, took over the mail-order stringy floppy business with his company, A&J Micro Drive.

One investor, BSR Ltd., the Hong Kong-based electronic components and consumer electronics company, acquired a third of the equity in Entrepo. BSR finalized the R&D on the wafer drive which it also manufactured. The BSR drive was used in the Rototronics Wafadrive.

Gallery

Products

A&J Micro Drive

Low cost, high-speed mass storage system that uses on “wafers” (endless loop tapes). Data transfer rate is many times faster than cassette and more reliable. Loads a 28k program in 24 seconds. Micro drive controller attaches to the expansion connector on the back and peripherals attach behind it. Most programs will run with little or

TS 1000

A&J Micro Drive Model 2000

The TS2068 version of the A&J Micro Drive has all the features of the original and includes a Centronics printer interface.

TS 2068

ESF Drive 2

Supplemental Exatron Stringy Floppy drive.

TS 1000 TS 2068

ESF/81 Monitor Program

The ESF/81 monitor program will allow you to program your Sinclair ZX81 at the most elementary level, in “machine language.” In. addition, the ESF/81 monitor will let you back up other machine-language programs stored on ESF wafers for extra security.

TS 1000

Microwafer

Continuous loop tape (“stringy floppy“) for the A & J Microdrive.

TS 1000 TS 2068

Articles

A TS1500 A&J Microdrive Problem and SolutionTS 1500
A&J Micro Drive SystemTS 2068
Subroutine to create a command line and execute it from within a running program.
A&J Microdrive 2000TS 2068 Hardware review
A&J NotesTS 1000
When using the A&J Microdrive “ESOS” (Exatron Stringy Operating System), there are times when you don’t want it to change your RAMTOP.
Across the PondZX81 TS 1000 TS 2068
Updated version of MSCRIPT; now returns to BASIC for file save/load. Feature added by Zebra. Greeting Card Designer from Zebra. ZPRINT-80, also from Zebra, supports Aerco, both Tasman, and A&J interfaces with LPRINT, LLIST, COPY.
Adapting Your Programs for the A&J MicrodriveTS 2068 Tutorial
Alpha Strings$TS 1000 TS 2068
Correction to A&J article in n14; RAM chips from Jameco; adjustments to WORM program; Callisto Software’s ZX Hi-Res.
Catalog Your A&J WafersTS 2068 Type-in program
Enhancing the A&J MicrodriveTS 2068 Type-in program
Programs to make working with the A&J Microdrive easier.
Items Gleamed from Other Club Newsletters
The Plotter reports that most repairs sent to Dan Elliot are completed and returned quickly. Only those requiring SCLDs take longer. CATS has article about connecting QL to RGB monitor. L.I.S.T. reports A&J Micro no longer supplying microdrives because they cannot obtain tapes.
LettersTS 2068 Type-in program
Micro-Prolog for Spectrum; A&J help request; 2068 music; MSCRIPT; Sinclair joysticks; 80 column VU-CALC printing; Spinning Wheel.
Making 2068 Back-Ups on the A&J MicrodriveTS 2068
Technique for backing software from tape to A&J Microdrive.
Mass Storage for the TS-2068TS 2068
List of mass storage options, including: ZX-Microdrive, A&J Microdrive, DAMCO/Rotronics Wafadrive, AERCO 2068 disk system and RAMEX Millenia K interface.
New Products and Services (Syntax v5 n2)
New products from Pheonix Enterprises, D. Lipinski Software, Robert Fingerle, A&J Microdrive, Maples Enterprises, Cottage Technology, JK Audio, Interface Design, Apropos Technology.
News From the Dealers
Curry Computing; Budget Robotics & Computing; American Design Components; WMJ Data Systems; Novelsoft; Chia-chi Chao; T & C Services; Lemke Software Development; Logic Sales Ltd.; A&J Assembly; Larken Electronics.
Notes, etc.
Quotes Jim Howell, owner of A&J Micro Drive, about the origin of the company.
Special Report: Mass Storage Devices For The TS 2068TS 2068 Hardware review
Brief overview of A&J Microdrive, DAMCO/Rotronics Wafadrive, Millenia K Disk Interface, Aerco FD-68 Interface.
Stringy Floppy for the Timex 1500TS 1000 TS 1500 Hardware review
Review and overview of the A&J Micro Drive stringy floppy system.
Tasword Two on MicrowaferTS 2068 Type-in program
How to migrate Tasword Two to A&J Stringy Floppy.
The A&J MicrodriveTS 2068 Hardware review
Review and overview of the system.
TS1500 A&J Microdrive Problem and SolutionTS 1500
Technique for bypassing a SAVE/VERIFY problem brought about by the combination of a TS 1500, TS 1016 RAM and the A & J Microdrive.
Vendor Report
Timex-Sinclair “survivor buttons; update on A&J Microdrives and wafers.
Verifying MScript 5T on A&J MicrodriveTS 2068