This page contains the construction notes, manuals, data sheets, photos etc I have for the commercial components of the Microtan 65 system.  Index
|Microtan 65 CPUs||   ||Video Cards||   ||Motherboards|
|TANEX||   ||Sound Cards||   ||Keyboards and Keypads|
|RAM Storage Cards||   ||EPROM Programmer Cards||   ||Power Supplies|
|ROM Storage Cards||   ||Clock and Timers||   ||Other Projects|
|DOS Cards||   ||IO Interface Cards|
Tangerine's original CPU card using 6502 Microprocessor.Users Manual
Tangerine's updated CPU card using 2716 EPROM to replace the Monitor PROMs.Users Manual
Note: TUGBUG cannot be used with a MT65-R CPU board in Single Board configuration (ie with the 3 links closed and no TANEX). Explanation here
Tangerine's original Expansion card with up to 7K Static RAM (2114) and 14K EPROM Space.
There is a modification to improve the Cassette Tape input performance. The two 22K resistors R2 and R3 should be removed and R5 changed from 120K to 10K.Users Manual
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).
In the above photograph R5 has been changed from 120K to 10K to improve Cassette Tape input performance but the two 22K resistors (R2 and R3 just below the terminal block) remain in circuit.Users Manual
Tangerine's bulk memory card which fully expands the Microtan's Address space to 47K ($BBFF). Features 32K dynamic RAM (4116) and 7K Static RAM (2114).
The following modification has been implemented to prevent periodical bit dropout:
Isolate M2 pin 2.
Connect 470R resistor between M2 pin 2 and D8 pin 11.
Connect 330pF capacitor between M2 pin 2 and 0v.
TUG's 64K Dynamic RAM CardConstruction Notes
Electronics Today International 64K Dynamic RAM Card. Replacement for the original ETI 64K DRAM card.Construction Notes
Tangerine's 32K ROM Storage Card. This enables between 1 and 8 continuous 4K blocks of the system memory map to be overlaid with images held in EPROM on the 32K Rom Card.Manual
TUG's EPROM Storage Card which can accommodate up to 16 2716 (2K) or 16 2732 (4K) EPROMs. The card uses a bank of 8 memory locations within the 1K of I/O space. Data may be transferred from any of the EPROMs located on the card into system user RAM under manual or software control. The PGM Toolkit EPROM includes a utility for transferring code from EPROM into RAM under user or program control.
TUG's Combo Card used for bulk storage of either EPROMs or RAM.Manual
Tangerine's Disc controller board that will operate up to 4 drives.Manual
Tangerine's original HRG card
Tangerine's upgraded HRG Card (Issue 2). Main change is replacing the 16 off 2114 RAM chips with 4 off MB8128 and different external video connections.Manual
Colour VDU Card supplied by Mousepacket. Provides 64 Character by 25 line colour tele-text display, 128 x 75 pixel colour graphics.Circuit Diagram
TUG's high resolution Video Card, later adopted by Tangerine giving 40 or 80 column text.Manual
The main operating system firmware for the Video 80/82 Card is VBug. Two versions were produced, VBug 1 and VBug 6. These are described on the Firmware page.
The Video 80/82 card is supported by the Video 80/82 Card Toolkit which is located in the TANEX socket E2. Two versions were produced supporting VBug 1 and VBug 6. These are described on the Firmware page.
Computer Aids intelligent graphics board compatible with any computer that has a parallel or serial port. 8K or 16K RAM providing either 256 x 256 or 512 x 256 Hi-Res graphics with 85 x 25 lines of text freely mixed with graphics. Composite Monochrome video output (RF option available for lower resolution graphics mode).Manual
TUG's Programmable Graphics Module provides 256 x 256 graphics using up to 64 programmable 8x16 pixel 'characters'.Manual
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 explains how various sounds eg Bangs, gunshots, whistling bombs and explosions can be obtained. 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.Manual
Electronics Today International magazine's Sound Card.Construction Notes
This EPROM programmer is capable of reading and programming both 2716 and 2732 EPROMs. An external power supply is required for the Vpp programming supply.Manual
This EPROM programmer board is capable of reading and programming 2716 EPROMs and is connected to three of the TANEX Parallel Data ports. The 27v Vpp programming voltage is supplied by three PP3 9v batteries.Circuit Diagram
Electronics Today International magazine's EPROM Programmer.Construction Notes
Electronics Today International magazine's Real Time Clock.Construction Notes
Tangerine's Parallel I/O Card.
A Nackmain Ltd Tanbus interface card designed to operate a Sinclair thermal paper printer.Instructions
Two Microtan motherboards are available; one from Microtan, the other from TUG. Both use 64 way DIN 41612 Type B, Rows A+B 'straight' solder sockets (RS Stock No.508-3195). These interface with the 64 way DIN 41612 Type B, Rows A+B Right-Angled solder Plug connectors (RS Stock No.406-206) mounted on the PCBs.
The most noticeable difference to Issue 1 is the addition of pull-up resistors for IC1.
Tangerine's first Power Supply. Used also in the Micron with a cut-down PCB and transformer mounted on the case chassis (photo).
Programmed 16F84 PICs are available to purchase from the Shop here.