This page contains the construction notes, manuals, data sheets, photos etc
I have for my Microtan 65 Full-System.
The circuit diagrams have been scanned at a 600dpi resolution so they
are around the 700KB size. They may take a while to download or you may not be able to display them in your
browser, but you can download them by right-clicking on the link.
They still have my scribbles on them and some of the
detail may be missing.
  Index
Tangerine's updated CPU card using 6502 Microprocessor. Users Manual Construction Notes Schematic Circuit Diagram Photo (NB My version has UHF modulator replaced with
connector to 80 Column Monitor. Also D3 moved to a 40/80 column selection switch on front panel.)
Tangerine's updated Expansion card. The most noticeable difference
is the replacement of the three 74LS367 hex 3-state buffer chips (M2-4) with 2 74LS244 octal 3-state buffer chips (M2-3) Users Manual Schematic Circuit Diagram Photo Printer Interface
Tangerine's bulk memory card which fully expands the Microtan's Address space
to 48K. Features 32K dynamic RAM (4116) and 7K Static RAM (2114). Circuit Diagram Photo
Main firmware for the Video 80/82 Card. Image
VBug is the operating system for Microtan's 80/82 Video Card. VBug 1.2 is
supplied for 40 Column use. VBug 6 (PTL) is supplied for full functionality. VDUTKT (PTL) Image
The Bulldog Video Ltd company was formed by ex-main Frame computer
designers made redundant by ICL, They were based in Birmingham and designed and marketed
products for The hobby and small-business microcomputer owner.
The first product to be released was a pro-grammable sound-generator board
for the Tangerine microcomputer. It is Tangerine sized, slots into the system motherboard and has an on-
board speaker and audio-amplifier
so that sounds can be produced as
soon as it has been inserted. Three terminal blocks
are provided so that it can be
connected up to external systems.
The board is centred on the
General Instrument AY- 3-8910; a
powerful sound-synthesis chip. The
sounds produced consist of a
mixture of three channels, each with
an independent tone generator and a
white-noise generator. The amplitude of the sound can be managed by
the envelope-generator; facility.
Documentation with the board
explained how various sounds can be
obtained. Bangs, gunshots, whistling
bombs and explosions are there in- be
included in games, Music creation is
also possible.
The sound board is programmed
via a set of 16 registers which can be
accessed from Basic, assembler or
the Tanbug M instruction set.
A Nackmain Ltd Tanbus interface card designed to operate a Sinclair thermal paper printer. Instructions Driver Photo
19 inch Rack
I now use a 19 inch rack that was sold by Tangerine specifically for the Microtan.
The original Vero Electronics 19 inch rack I had for this system now houses the 6809 system.
Motherboard
This board is fitted in the Microtan 65 full system.