6809 Microtan System
This page contains the construction notes, data sheets, operating instructions, photos etc
I have for the 6809 Microtan System.
6809 Single Board Processor
Ralph Allen's CPU card using 6809 Microprocessor.
Component List
These are construction notes for a different 6800 series single-board controller for the Microtan.
Construction Notes
RALBUG v1.4 EPROM
Listing
Image F800-FFFF (Intel Format)
Image F800-FFFF (Binary)
Tanex
Tangerine's Expansion card fitted for but not with 7K Static RAM (2114) and 14K EPROM Space.
The board has been modified for use in the 6809 system.
The outputs from L3 a & b control the board's EPROM Chip Enable (CE)inputs.
On a standard board these are driven from the TANBUS R/W signal line.
For use in the 6809 system, L3 has been modified to receive control from the TANBUS O1 signal line
as shown in the following two photos.
Photo
Photo
For a reason not known to me, the Tanex PCBs have pins a17 (FB) and b17 (NMI) linked together
even though the board does not use either of these signals.
This is not a problem if the board is used either with a TUG or MICRON motherboard
because the TANEX slot pin a17 is not connected to the NMI signal line.
However, on the Tangerine MT0010 motherboard, both the TANEX slot a17 and b17 pins
are connected to the FB and NMI signal lines respectively.
To avoid creating an issue, the DIN 41612 connector pin b17 has been cut
at the rear of the connector as shown in the following photo.
Photo
Circuit Diagram
Schematic
TANRAM
Tangerine's bulk memory card which is usually used to fully expand the Microtan's Address space
to 48K. Features 32K dynamic RAM (4116) and 7K Static RAM (2114).
This TANRAM has been modified to move the addressing range of the on-board memory.
It is possibly being used either as a cache or Ram-disk.
Construction Notes
Circuit Diagram
Schematic
32K RAM Cards
Three Ralph Allen's 32K Dynamic RAM/EPROM Cards are fitted in this system.
Two are configured as RAM cards proving a full 64K memory. The third is
configured as an EPROM storage card.
Construction Notes
Photo (RAM1)
Photo (RAM2)
32K EPROM Card
The third Ralph Allen's 32K Dynamic RAM/EPROM Card is
configured as an EPROM storage card.
EPROMs
ASCII
Listing
Image F800-FFFF (Intel Format)
Image F800-FFFF (Binary)
DATA
Listing
Image F800-FFFF (Intel Format)
Image F800-FFFF (Binary)
GRAPH
Listing
Image F800-FFFF (Intel Format)
Image F800-FFFF (Binary)
SYNTAX
Listing
Image F800-FFFF (Intel Format)
Image F800-FFFF (Binary)
Colour Video Controller Card
Ralph Allen's Colour Video Card
Construction Notes
Disc Controller / Real Time Clock
Ralph Allen's Disc controller/Real Time Clock board that will operate up to 4 drives.
Construction Notes
Disk Controller FDC1793 Details
Disk Controller FDC9216 Details
System Rack
The system rack is my original 19 inch rack I purchased for my Full System back in the 1980s.
It was purchased from Vero Electronics and uses the RS 19 inch 3U unit with 0.2 inch spacing
guide support strips and tapped strips.
RS 19 inch Rack Specification
Motherboard
Microtan's 12 Slot Motherboard which supports M65, Tanex and 10 other TANBUS cards.
TANBUS Connections
Construction Notes
Schematic
Circuit Diagram
System Power Supply
Ralph Allen's power supply
Photo