Tangerine MICROTAN 65
Encyclopedia
The Tangerine
Microtan 65 (sometimes abbreviated M65) was a 6502
based single board microcomputer
, first sold in 1979, which could be expanded into, what was for its day, a comprehensive and powerful system. The design became the basis for what later became the ORIC, ATMOS and later computer
s, which had similar keyboard addressing and tape
I/O as in the Microtan 65. The Microtan 65 had a single step function that could be used for debugging
at the hardware
level. The computer was available as ready-built board
s or as kits consisting of board and components
requiring soldering
together.
The Microtan 65 was intended as a general purpose microcomputer which could be used by laboratories
, Original Equipment Manufacturers (OEM)s and the computer enthusiast, and it was designed with expandability in mind. In this way the customer could customise the system, be it as a specialised control system
, as a learning tool, or as a general purpose computing device.
Price of the Microtan 65 board in 1981 was £79.35 (inc. VAT
) in kit form or £90.85 ready-assembled. The system was not generally available in the shops, one of the few stockists at the time being Henry's Radio of Edgware Road, London.
The Microtan 65 was quite simple by today's standards, with:
was flicker free. At the time a lot of microcomputers would either access the screen memory asynchronously
to the video timing (causing flicker and splats on the screen), or would write to the screen memory during a non-display period (which was slow). The Microtan 65 got over this problem by making use of a major feature of the 6502
. The 6502 (unlike most other CPUs) has a regular period in each instruction cycle when all CPU activity is inside the chip, leaving the external memory available without using complex external arbitration logic. This made video display
design simpler and meant that video accesses could be made at maximum speed. This technique is also used on the ORIC and ATMOS computers.
The 32×16 characters was the reason that the 6502 was clocked
at 750 kHz. To get the circuitry to work at a (nearly) standard video rate meant that the pixel
clock had to be 6 MHz. When the Microtan 65 was designed only a 1 MHz 6502 was available, and so 750 kHz was used (6 MHz divided by 8).
program (later increased to a 2K) was called TANBUG. The software facilities were rudimentary:
memory address):
The screen memory occupies the space between $200 and $3FF. In addition to the standard 8 bit
s of screen RAM
, there was an additional single bit RAM shadowing the $200 to $300 space. This was configured as a 9th bit
write-only plane, and was used by the Microtan 65 for rudimentary, or "chunky", graphics. Setting the 9th bit displayed a Minitel
type block graphic.
The display is 32 characters across by 16 lines down, with memory address $200 representing the top left hand displayed character, $220 the second row, etc. The character representation is standard ASCII
. Several pieces of Microtan 65 software write to the bottom line by writing to memory starting at $3E0 - the leftmost character on the bottom line, rather than vectoring through TANBUG.
in the Microtan 65 is decoded into a 16 KB space to simplify the hardware
. In fact the 1 KB of RAM is mirrored through the bottom 32 KB, the I/O through the next 16 KB, and the EPROM
through the top 16 KB. If you added an expansion board (see TANEX below) the decoding was modified and the wasted space reclaimed.
In common with other 6502
designs, I/O is mapped
into the memory space. There is no dedicated I/O space as on the Z80, 8086
etc. The I/O ports are (when fully decoded):
Adding a TANEX board provided a number of features:
Without a TANEX board, and due to deliberately ambiguous address decoding, the address $F7F7 would appear to the 6502
to have the same data as $FFF7. In TANBUG, this is a jump to an internal monitor routine. With TANEX installed, $F7F7 is decoded properly, and that address is an entry point into XBUG. XBUG provided features such as cassette tape loading and saving, a simple assembler / disassembler
, hex
calculator.
The ROM
sockets on TANEX could be used to run a 10K Microsoft Extended BASIC
, a two-pass assembler, or even (and more likely given the hardware bias of the Microtan 65) code written for a specific hardware control application.
Price of the TANEX board in 1981 was £49.45 as a "minimum configuration" kit - lacking one of the 6522 VIAs and the 6551 and with 1K of RAM - and £60.95 for a similar board fully assembled. TANEX was also available with the board fully populated with chips (although excluding XBUG, ROMs & BASIC) and in this form the costs were £103.16 for the kit and £114.66 ready assembled.
The Microtan 65 was designed as a modular system able to be expanded as required, and for this each board included an 80-pin connector at one end allowing it to be plugged into a backplane-type motherboard
. A simple two-socket "Mini Motherboard" connected the Microtan 65 and TANEX boards for minimum expansion and in this form the system was also available ready-built from Tangerine, complete with case and full ASCII keyboard, as the Tangerine Micron, costing £395.00 in 1981. For further expansion the builder could purchase the full "System Motherboard" which featured an additional ten sockets, bringing the total available sockets to twelve. For housing this, a "System Rack", rack-based case was available, in black and silver with a black front panel trimmed in Tangerine's trademark orange.
Additional boards became available with time, including a 40K memory board - TANRAM, made up of 32K of dynamic
and 8K of static
RAM, bringing the total non-paged memory to 48K, a dedicated parallel I/O
board featuring 16 parallel input/output port
s; a similar dedicated serial I/O board featuring 8 serial input/output ports, a disk controller
board for use with disk drives
, a Disk Operating System
- TANDOS 65, a high resolution graphics
board featuring 8K of static graphics RAM giving a resolution of 256 × 256 pixel
s, a dedicated 32K ROM
board, (aimed mainly at OEM
and general purpose applications or for use with AIM
KIM
and SYM systems), capable of holding either 8 × 2732 or 16 × 2716 EPROMs; and a 32K RAM board featuring two 16K banks of 4116 dynamic RAM, again intended for similar purposes to the 32K ROM board. In addition, several third-party suppliers offered boards designed for use with the Microtan 65 system.
In addition to the BASIC programming language
Tangerine also released on disk TANFORTH, an extended version of FIG FORTH featuring a full FORTH assembler and editor
.
Tangerine Computer Systems
British microcomputer company Tangerine Computer Systems was founded in 1979 by Dr. Paul Johnson, Mark Rainer and Nigel Penton Tilbury in St. Ives, Cambridgeshire...
Microtan 65 (sometimes abbreviated M65) was a 6502
MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
based single board microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
, first sold in 1979, which could be expanded into, what was for its day, a comprehensive and powerful system. The design became the basis for what later became the ORIC, ATMOS and later computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s, which had similar keyboard addressing and tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
I/O as in the Microtan 65. The Microtan 65 had a single step function that could be used for debugging
Debugging
Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware, thus making it behave as expected. Debugging tends to be harder when various subsystems are tightly coupled, as changes in one may cause bugs to emerge...
at the hardware
Computer hardware
Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...
level. The computer was available as ready-built board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s or as kits consisting of board and components
Electronic component
An electronic component is a basic electronic element and may be available in a discrete form having two or more electrical terminals . These are intended to be connected together, usually by soldering to a printed circuit board, in order to create an electronic circuit with a particular function...
requiring soldering
Soldering
Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...
together.
The Microtan 65 was intended as a general purpose microcomputer which could be used by laboratories
Laboratory
A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
, Original Equipment Manufacturers (OEM)s and the computer enthusiast, and it was designed with expandability in mind. In this way the customer could customise the system, be it as a specialised control system
Control system
A control system is a device, or set of devices to manage, command, direct or regulate the behavior of other devices or system.There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls...
, as a learning tool, or as a general purpose computing device.
Price of the Microtan 65 board in 1981 was £79.35 (inc. VAT
Vat
Vat or VAT may refer to:* A type of container such as a barrel, storage tank, or tub, often constructed of welded sheet stainless steel, and used for holding, storing, and processing liquids such as milk, wine, and beer...
) in kit form or £90.85 ready-assembled. The system was not generally available in the shops, one of the few stockists at the time being Henry's Radio of Edgware Road, London.
Main Board
- an NMOS 6502MOS Technology 6502The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
CPU running at 750 kHz clock rateClock rateThe clock rate typically refers to the frequency that a CPU is running at.For example, a crystal oscillator frequency reference typically is synonymous with a fixed sinusoidal waveform, a clock rate is that frequency reference translated by electronic circuitry into a corresponding square wave... - 1K byte of RAM, used both for display memory and user programs
- 1K byte of ROMRead-only memoryRead-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
for the monitor program (not even called an operating systemOperating systemAn operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
) - video logic and a televisionTelevisionTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
RF modulatorRF modulatorAn RF modulator is a device that takes a baseband input signal and outputs a radio frequency-modulated signal....
, for the 16 rows of 32 characters display - a software scanned hexadecimalHexadecimalIn mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
keypadKeypadA keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad... - an optional ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
keyboardComputer keyboardIn computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
Display
The major advance that the Microtan 65 had over a lot of the competition at that time was that the video displayComputer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
was flicker free. At the time a lot of microcomputers would either access the screen memory asynchronously
Asynchronous operation
In telecommunications, asynchronous operation or asynchronous working is where a sequence of operations is executed such that the operations are executed out of time coincidence with any event...
to the video timing (causing flicker and splats on the screen), or would write to the screen memory during a non-display period (which was slow). The Microtan 65 got over this problem by making use of a major feature of the 6502
MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
. The 6502 (unlike most other CPUs) has a regular period in each instruction cycle when all CPU activity is inside the chip, leaving the external memory available without using complex external arbitration logic. This made video display
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
design simpler and meant that video accesses could be made at maximum speed. This technique is also used on the ORIC and ATMOS computers.
The 32×16 characters was the reason that the 6502 was clocked
Clock rate
The clock rate typically refers to the frequency that a CPU is running at.For example, a crystal oscillator frequency reference typically is synonymous with a fixed sinusoidal waveform, a clock rate is that frequency reference translated by electronic circuitry into a corresponding square wave...
at 750 kHz. To get the circuitry to work at a (nearly) standard video rate meant that the pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
clock had to be 6 MHz. When the Microtan 65 was designed only a 1 MHz 6502 was available, and so 750 kHz was used (6 MHz divided by 8).
Software
The 1K byte monitorOperating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
program (later increased to a 2K) was called TANBUG. The software facilities were rudimentary:
- M = Memory modify / examine
- L = List a block of memory
- G = Go command (Run a program)
- R = RegistersProcessor registerIn computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
display / modify - S = set Single step mode
- N = set Normal mode (cancel S command)
- P = Proceed command (execute next instruction in Single step mode)
- B = set BreakpointBreakpointIn software development, a breakpoint is an intentional stopping or pausing place in a program, put in place for debugging purposes. It is also sometimes simply referred to as a pause....
s - O = calculate Offset for use in branch instructions
- C = Copy a block of memory
Memory Map
The Microtan 65 memory map is shown below ($ representing a hexadecimalHexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
memory address):
- $0000 Zero PageZero pageThe zero page is the series of memory addresses at the absolute beginning of a computer's address space; that is, the page whose starting address is zero. The size of a "page" depends on the context, and the significance of zero-page memory versus higher addressed memory is highly dependent on...
- $0100 StackStack (data structure)In computer science, a stack is a last in, first out abstract data type and linear data structure. A stack can have any abstract data type as an element, but is characterized by only three fundamental operations: push, pop and stack top. The push operation adds a new item to the top of the stack,...
- $0200 Screen RAMRam-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
- $0300
- $0400 End of Microtan 65 RAM - map continued from $0400 to $0700 as RAM on TANEX
- $8000 I/O
- $C000
- $F800 TANBUG V2
- $FFFF
The screen memory occupies the space between $200 and $3FF. In addition to the standard 8 bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
s of screen RAM
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
, there was an additional single bit RAM shadowing the $200 to $300 space. This was configured as a 9th bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
write-only plane, and was used by the Microtan 65 for rudimentary, or "chunky", graphics. Setting the 9th bit displayed a Minitel
Minitel
The Minitel is a Videotex online service accessible through the telephone lines, and is considered one of the world's most successful pre-World Wide Web online services. It was launched in France in 1982 by the PTT...
type block graphic.
The display is 32 characters across by 16 lines down, with memory address $200 representing the top left hand displayed character, $220 the second row, etc. The character representation is standard ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
. Several pieces of Microtan 65 software write to the bottom line by writing to memory starting at $3E0 - the leftmost character on the bottom line, rather than vectoring through TANBUG.
Input/output
I/OInput/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
in the Microtan 65 is decoded into a 16 KB space to simplify the hardware
Hardware
Hardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....
. In fact the 1 KB of RAM is mirrored through the bottom 32 KB, the I/O through the next 16 KB, and the EPROM
EPROM
An EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages...
through the top 16 KB. If you added an expansion board (see TANEX below) the decoding was modified and the wasted space reclaimed.
In common with other 6502
MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
designs, I/O is mapped
Memory-mapped I/O
Memory-mapped I/O and port I/O are two complementary methods of performing input/output between the CPU and peripheral devices in a computer...
into the memory space. There is no dedicated I/O space as on the Z80, 8086
Intel 8086
The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
etc. The I/O ports are (when fully decoded):
- Write to $BFF0 Clear KeyboardComputer keyboardIn computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
Flag (Keyboard would generate an IRQ) - Read from $BFF0 Turn Graphics On (enables "9th bitBitA bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
" graphics writes)
- Write to $BFF1 Used by the hardwareHardwareHardware is a general term for equipment such as keys, locks, hinges, latches, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts. Household hardware is typically sold in hardware stores....
single step
- Write to $BFF2 To write a scan pattern to the hexHexadecimalIn mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
keypadKeypadA keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad...
(if fitted)
- Write to $BFF3 Turn off Graphics (disable "9th bitBitA bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
" graphics writes) - Read From $BFF3 Read Keyboard Port (either keypad or ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
keyboard)
TANEX expansion board
- an add-on to TANBUG called XBUG
- space for an additional 7K bytes of RAMRam-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
- five EPROMEPROMAn EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages...
sockets - two 6522 VIAs
- a 6551 UART, providing a cassette interface for storing and retrieving programs (300 baud CUTSKansas City standardThe Kansas City Standard , or Byte standard, is a digital data format for audio cassette drives. Byte magazine sponsored a symposium in November 1975 in Kansas City, Missouri to develop a standard for storage of digital computer data on inexpensive consumer quality cassettes, at a time when...
, and 2400 baudBaudIn telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
), and a serial interface
Without a TANEX board, and due to deliberately ambiguous address decoding, the address $F7F7 would appear to the 6502
MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
to have the same data as $FFF7. In TANBUG, this is a jump to an internal monitor routine. With TANEX installed, $F7F7 is decoded properly, and that address is an entry point into XBUG. XBUG provided features such as cassette tape loading and saving, a simple assembler / disassembler
Disassembler
A disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. A disassembler differs from a decompiler, which targets a high-level language rather than an assembly language...
, hex
Hexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
calculator.
The ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
sockets on TANEX could be used to run a 10K Microsoft Extended BASIC
Microsoft BASIC
Microsoft BASIC was the foundation product of the Microsoft company. It first appeared in 1975 as Altair BASIC, which was the first BASIC, and the first high level programming language available for the MITS Altair 8800 hobbyist microcomputer....
, a two-pass assembler, or even (and more likely given the hardware bias of the Microtan 65) code written for a specific hardware control application.
Price of the TANEX board in 1981 was £49.45 as a "minimum configuration" kit - lacking one of the 6522 VIAs and the 6551 and with 1K of RAM - and £60.95 for a similar board fully assembled. TANEX was also available with the board fully populated with chips (although excluding XBUG, ROMs & BASIC) and in this form the costs were £103.16 for the kit and £114.66 ready assembled.
Further Expansion
Motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
. A simple two-socket "Mini Motherboard" connected the Microtan 65 and TANEX boards for minimum expansion and in this form the system was also available ready-built from Tangerine, complete with case and full ASCII keyboard, as the Tangerine Micron, costing £395.00 in 1981. For further expansion the builder could purchase the full "System Motherboard" which featured an additional ten sockets, bringing the total available sockets to twelve. For housing this, a "System Rack", rack-based case was available, in black and silver with a black front panel trimmed in Tangerine's trademark orange.
Additional boards became available with time, including a 40K memory board - TANRAM, made up of 32K of dynamic
Dynamic random access memory
Dynamic random-access memory is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. The capacitor can be either charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1...
and 8K of static
Static random access memory
Static random-access memory is a type of semiconductor memory where the word static indicates that, unlike dynamic RAM , it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit...
RAM, bringing the total non-paged memory to 48K, a dedicated parallel I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
board featuring 16 parallel input/output port
Computer port (hardware)
In computer hardware, a port serves as an interface between the computer and other computers or peripheral devices. Physically, a port is a specialized outlet on a piece of equipment to which a plug or cable connects...
s; a similar dedicated serial I/O board featuring 8 serial input/output ports, a disk controller
Disk controller
The disk controller is the circuit which enables the CPU to communicate with a hard disk, floppy disk or other kind of disk drive.Early disk controllers were identified by their storage methods and data encoding. They were typically implemented on a separate controller card...
board for use with disk drives
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
, a Disk Operating System
Disk operating system
Disk Operating System and disk operating system , most often abbreviated as DOS, refers to an operating system software used in most computers that provides the abstraction and management of secondary storage devices and the information on them...
- TANDOS 65, a high resolution graphics
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
board featuring 8K of static graphics RAM giving a resolution of 256 × 256 pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, a dedicated 32K ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
board, (aimed mainly at OEM
Original Equipment Manufacturer
An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
and general purpose applications or for use with AIM
AIM-65
The Rockwell AIM-65 computer was a development computer based on the MOS Technology 6502 microprocessor introduced in 1976. The AIM-65 was essentially an expanded KIM-1 computer. Available software included a monitor with line at a time assembler/disassembler, BASIC interpreter, assembler, Pascal,...
KIM
KIM-1
The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...
and SYM systems), capable of holding either 8 × 2732 or 16 × 2716 EPROMs; and a 32K RAM board featuring two 16K banks of 4116 dynamic RAM, again intended for similar purposes to the 32K ROM board. In addition, several third-party suppliers offered boards designed for use with the Microtan 65 system.
In addition to the BASIC programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
Tangerine also released on disk TANFORTH, an extended version of FIG FORTH featuring a full FORTH assembler and editor
Source code editor
A source code editor is a text editor program designed specifically for editing source code of computer programs by programmers. It may be a standalone application or it may be built into an integrated development environment ....
.
External links
- This article was based on: Microtan 65 Hardware and Software Description by Ray Gannon and credited Distribute as you like. Credit me if you do.
- Geoff Mcdonald's webpage - author's experience with the Microtan 65
- Fabrice Frances' website - includes a Microtan 65 emulatorEmulatorIn computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...
written in JavaJava (programming language)Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities... - Binary Dinosaurs - tracing the history of computers
- www.microtan.ukpc.net - manuals, ROM images, magazine and newsletter articles