ATMOS TECHNICAL SPECIFICATIONS





Oric offer 16K and 48K Atmos models, both featuring 'typewriter' style keyboards and we've included detailed specifications of the computer's capabilities for you below.
You can connect the MicroDisc and Four Colour Printer to the Atmos to create a
professional computer system. If you'd like to know the full details of the Atmos and the Oric peripherals — read on...
6502A Microprocessor with 16K ROM containing BASIC interpreter and operating system. RAM uses state of the art dynamic memories for high board density and low power dissipation. 16K Byte or optionally 48K Byte. 48K model contains 64K of RAM with 16K overlaid by ROM. External control signal
allows the use of full 64K RAM or may be used to externally increase ROM.

Keyboard 57 moving keys with tactile feedback. Full upper and lower case with correctly positioned space bar. Full typewriter pitch. Key layout is standard computer type with ESC, CTRL, RETURN and additional cursor control keys. All keys have auto repeat.

Display Will drive a PAL UHF colour or black and white television receiver. Approximately Channel 36. RGB output also provided on DlN socket with 270 configuration.
Screen — Character Mode (Memory Mapped) 28 lines of 40 characters producing display very similar to Teletext. Character set is standard ASCII which is enhanced by the addition of 80 user definable characters. ASCII characters may also be re-defined as these are down loaded into RAM on power-up. Serial attributes are used to control display features, as in Teletext, and take up one character position. All remaining characters on that line are affected by the serial attribute until either the line ends or another serial attribute.
Display features are:-
a. Select background colour (paper) from one of eight.
b. Select foreground colour (ink) from one of eight.
c. Flash characters on and off approximately twice a second.
d. Produce double height characters (even line top, odd line bottom).
e. Switch over to user definable characterset. This feature is used to produce Teletext style colour graphics which does not require any additional RAM to operate.
Available colours are Black, Blue, Red, Magenta, Green, Cyan, Yellow and White.
Each character position also has a parallel attribute, which may be operated on a character by character basis, to produce video inversion. The display has a fixed black border.

Screen — Graphics Mode (Memory Mapped) 200 pixels vertically by 240 pixels horizontally plus 3 lines of 40 characters (same
as character mode) at the bottom of the screen to display system information and to act as a window on the user program while still viewing the graphics display. Can also be used to input direct commands for graphics and see effect instantly without having to switch modes. Graphics display operates with serial attributes in the same way as characters except that the display is now considered as 200 lines by 40 graphics cells. Each graphic cell is therefore very flexible by having 8 foreground and 8 background colours and flashing patterns. The video invert parallel attribute is also useable in this mode. ASCII characters may be 'painted over' the graphics area thus enabling the free mixing of graphics and text.

Sound Uses internal loudspeaker and amplifier and can also be connected to external Hi-Fi system via a DIN connector. A three channel sound synthesizer (The General Instrument 8912) as used in arcade games machines which can produce musical notes from sub-sonic to supersonic frequencies. Envelope of sound output is programmable and can be used to synthesize various musical instruments.
Pseudo Random Noise generator (providing a hissing sound can be mixed into each channel). Provides interesting sound effects for video games.

Sound Commands Three tones can be produced directly from the keyboard.
a. A high beep when an alphanumeric key is pressed.
b. A low beep when a special key is pressed (e.g. Delete, Carriage Return).
c. A bell tone when the control G key is pressed.
The user can switch these sounds off as desired. There are four preprogrammed sound commands for use within programs. These are:—
i) PING, produces a bell-like tone, is also used as control G tone.
ii) SHOOT, simulates a gunshot.
iii) EXPLODE, creates the sound of an explosion.
iv) ZAP, produces a space-invader 'laser' sound. To facilitate the creation of other sounds there are three general purpose commands:
SOUND, MUSIC and PLAY. SOUND has a range of 15Hz to 62kHz. MUSIC will play notes within a seven octave range. Up to 3 voices can be used at one time.

Cassette Interface Connect via DIN socket. Uses Tangerine format which has been field proven over
4 years and thousands of systems. Operates at super reliable 300 baud or reliable super fast 2400 baud. A tone leader allows tape recorders' automatic level control to stabilise before first recording filename and then dumping program/data with parity. At the end of recording several check sums are recorded which will be checked on loading to verify correct operation.

A Schmitt trigger circuit is used on the tape input to remove noise. The Tangerine format is so good it is the one other manufacturers are copying. AII types of information may be saved such as programs, data, arrays, blocks of memory screen displays. After saving, correct recording may be verified before deleting information in memory. Remote motor control of tape recorder is provided; essential for the loading and saving of data files.

Available commands are CLOAD, CSAVE (for programs and memory dumps) STORE, RECALL (for arrays). Both programs and arrays may have a filename up to 16 characters. Arrays may be string integer or real. Various command extensions can be used such as S for slow speed, V for verify (CLOAD and CSAVE only) AUTO for autorunning of programs. A and E for start and end of memory dumps.

Expansion Port and Micro Drive Interface Full data, address and control information forthe6502A Micro Processor; for connection of add-ons. Can also be used for user designed hardware interfaces. Useful control lines allow RAM and ROM to be externally expanded (ideal for adding ROM cartridges).

Printer Port Standard Centronics parallel interface allows connection of a multitude of different
types of printer from very cheap thermal types to high speed matrix printers or wordprocessors quality daisywheel printers.

Reset Machine resets to character mode on power up and clears program memory. A key on the base of the machine provides a warm start which will return to command mode (after a program crash or never ending loop) without destroying program or data.
Mathematical Operations and Functions The standard +,-,x,/ are available as are
the functions, sine, cosine, tangent and arctan, exponential, log, absolute value, integer value, sign and square root. Full algebraic precedence is used to ensure that calculations are performed in the correct order. There are also functions to display the amount of free memory and the position of the cursor. PEEK and POKE allow direct access into memory. The boolean operators of AND, OR and
NOT are available as are relational operators:
=, <, >, <> (not equal) <=, >=. Machine code subroutines may be called with the USR command.User defined functions are available using DEF-FN and program data may be manipulated using DATA, READ and RESTORE, ON GOSUB and ON GOTO allow programmed jumps to a choice of locations.
All mathematical functions are accurate to 9 digits with a range of between 2.93874 x 10-39 to1.70141*10^38

An immediate mode allows the computer to be used as a calculator.

String Operations and Functions Strings may be up to 255 characters in length. There are a number of functions to manipulate strings: ASC, CHR$, LEFT$, LEN, MID$, RIGHT$,TAB,VAL Strings may be concatenated (joined together) using +. Strings may be computed using, =, <, >,=<,= >, 0.

Variables Variable names may be of any length, although only the first two characters are acted upon. They may consist of combinations of the letters A-Z and numbers 0-9. The following suffixes may be applied to variable names.
$ Indicates a string variable
% Indicates an integer variable (-32768 to +32767).
No Suffix Indicates a normal floating point variable.
Arrays may have up to 255 dimensions and may be integer, floating point or strings.
Arrays are named as for variables (see above).

Dimensions

Height: 52mm Width: 280mm
Depth: 175mm Weight: 1.1Kg


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BASIC Keywords ABS AND ASC ATN CALL CHAR CHR$ CIRCLE CLEAR CLOAD CLS CONT COS CSAVE CURMOV CURSET DATA DEEK DEF DIM DOKE DRAW EDIT END EXP EXPLODE FALSE FILL FN FOR...TO... (STEP) NEXT FRE GET GOSUB GOTO GRAB HEX$ HIMEM HIRES IF...THEN... (ELSE) INK INPUT INT KEY$ LEFT$ LEN LET LIST LLIST LN LOG LORES LPRINT MID$ MUSIC NEW NOT ON OR PAPER PATTERN PEEK PI PING PLAY PLOT POINT POKE POP POS PRINT PULL RECALL READ RELEASE REM REPEAT RESTORE RETURN RIGHTS$ RND RUN SCRN SGN SHOOT SIN SOUND SPC SQR STOP STORE STR$ TAB TAN TEXT TROFF TRON TRUE USR VAL WAIT ZAP

Please note: More BASIC commands are available when using Sedoric.

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