This page contains the details of a project being undertaken by David Fry and me to build a modern version of the Microtan 65 system. Many of the items developed are available for purchase at the shop here
The PCBs are being developed using KiCad (kicad-pcb.org). The KiCad project files have been archived in the ZIP files in the relevant sections below and include the Gerber files for PCB production.  Index
|Serial Keyboard Interface|
This is a modern replacement for Tangerine's latest version CPU card. It is fully compatible with the original and has the following enhancements:
Bare MT65-R CPU v1.0b PCBs are available for sale in the Shop
Note: The FORTH programs require Rev2 code for its 'Words' to be displayed correctly. This is because the 6502 code stores Words with the 8th bit of the last character set to denote the end of the word.
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
This is a modern replacement for Tangerine's Tanex card. It is fully compatible with the original and has the following specification:
Note: UART 6551 may be substituted with 65C51 in PCB versions 1.0b and above.
Bare Tanex-Plus v1.0b PCBs and programmed memory are available for sale in the Shop
Modern replacement for the Tangerine TANDOS 65 board.Manual
EPROM U17 is a 2732 EPROM containing both the TANDOS and DBASIC images.TANDOS Listing
Modern replacement for the Tangerine High Resolution Graphics (HRG) board.
Provides 256x256 pixel high resolution graphics screen. When used with the HRG Toolkit can also provides a 51 character x 45 line high-resolution text screen. Modulated UHF and composite video outputs available.Manual
Bare HRG v1.0b PCBs and programmed Toolkit EPROMs are available for sale in the Shop
Replacement for Tangerine KeypadKiCad Archive (zip file)
What started life as a bespoke 19 inch 4U system rack has been modified to accommodate the Microtan Circuit Boards and fit into my existing Vero 19 inch enclosure. This involved removing the end plates, cutting them down to size and re-drilling the holes for the screws that hold the 6 longitudinal rails in place.
The motherboard has been designed to accommodate CPU, TANEX and 5 expansion slots. The slots are 1 inch apart to allow for a wider PCB form factor and increased cooling. Tanbus expansion slot signal lines 19b and 19b have been earmarked for Video1 and Video2 signal. Each may be configured by on-board jumpers to link to Tanbus CPU slot signal lines 20a or 20b.
The first production run has been completed and one of the first-offs has been installed in the System Rack. This is being used to test and repair a number of Microtan boards.KiCad Archive (zip file)
Power is supplied to the motherboard by a 65W Meanwell 1496-RQ-65B Quad Output enclosed power supply providing dual 12 volt and 5 volt supplies.Photo
Construction notes for creating a Serial Keyboard interface to the Microtan 65 supplied by Danny Page. This interface enables a PC-AT keyboard to used with the Microtan system.Circuit Diagram
Both professionally manufactured bare PCBs and programmed 16F84 PICs are available for purchase from the Shop.