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NORD COMPUTER SYSTEMS

ND652 VERSATEC CONTROLLER DMA

INTRODUCTION

The Direct Memory Access (DMA) Printer/Plotter controller — ND 652 — interfaces the NORD-10/S computer and the Versatec Printer/Plotter. The controller, once initiated, has the capability of performing a transfer of one line or a specified number of words without any processor intervention. When using a word counter to specify the number of words, transfer of several lines may be initiated. After the controller device registers are initialized, all transfer will take place under supervision of the controller. The processor may be notified by an interrupt when one line or the specified number of characters have been transferred to the Matrix Printer/Plotter.

FEATURES

The plotter may be used in three different modes:

  • Plot mode
  • Print mode
  • Simultaneous print/plot

PRODUCT DESCRIPTION

Data Format

Print and plot data are transferred in word mode (2 bytes) between memory and the controller, and in byte mode between the controller and the Matrix Printer. The controller has a 16 bit (2 byte) buffer for temporary storage of data.

Printing

The print input accepts ASCII format. 7 or 8 level code (data bit 8 is not used).

The character generator in the Matrix Printer contains a Read Only Memory (ROM) in which 64 or 96 characters are stored. Up to 80 characters may be stored in the print buffer for 8 1/2" machines, or 132 characters for 11" machines.

When the buffer is full (1 line of characters) or a control character is received, the line is automatically printed.

Plot Operation

Data consists of 8 bit, binary unweighted bytes. A complete raster scan (a single plotted line) consists of 70 8-bit bytes, totaling 560 bits for 8 1/2" machines, or 128 8-bit bytes, totaling 1,024 bits on 11" machines.

Each dot corresponds to a single bit in the buffer. If a bit is "1" a black dot is plotted at the point corresponding to the bit position in the buffer.

When the last byte is stored in the plotter buffer, a single scan is automatically generated and one row of data points is plotted. A space equal to the horizontal resolution is generated and the Matrix Printer is then ready to receive another scan of plot data.

When using line mode, the transfer is terminated when one line is transferred from the buffer in memory to the plotter buffer.

When using word mode, the transfer is terminated when the word counter is decremented to zero.

After a transfer, one of the "Remote Control Signals" may be used to empty the plotter buffer (if not full line).

Simultaneous Print/Plot (SPP) Operation

Simultaneous Print/Plot (SPP) Operation is provided to permit direct overlaying of character data generated by the Internal Matrix Character Generator, with plotting data generated on a dot basis. This is an optional feature on Matrix Printers/Plotters.

Normal operation consists of first filling the print buffer. If the buffer is not filled, the line must be terminated by a CR (Carriage Return) code. Mode is changed, and unweighted binary plot data is now loaded into the plot buffer until the plot buffer is full (one line) and a single scan is generated. Note that the writing process is controlled by the plot buffer.

[ASCII Art or Mermaid Diagram Placeholder, as necessary]

652 A2-2000-1178


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Specifications

Connection to Plotter

The controller is connected by the parallel interface connector, 8 data lines and 12 control lines. The controller may be used for all the types of Versatec Matrix Printers/Plotters. - Maximum cable length: 15 m (50 feet) - Connector type: Cannon DCC-37P, Mating connector Cannon DCC-37S

Connection to Computer

The interface fits into a standard Norsk Data I/O crate and consists of: - 1 board in standard I/O position - 3 boards in specially wired positions

Contact Information

Country Company Address Telephone
Norway Norsk Data A.S Lindern øyen, nord 20, Box 4 - Lindeb e rg gård Oslo 10 Tel. 02-396101, Tlx. 18661 nd n
Denmark Norsk Data ApS Oerwedvej 5 2840 HOLTE Tel. 02-425055
West Germany Norsk Data Deutschland GmbH Abraham-Lincoln-Strasse 30 6200 WIESBADEN Tel. 06121-764220, Tlx. 4186370 noda
Sweden ND Norsk Data AB Kanalvaggen 3, Box 2031 194 02 UPPLANDS VÄSBY Tel. 0760-86500, Tlx. 13528 nordata s
France Norsk Data France "Le Brevent", Avenue du Jura 01210 FERNEY-VOLTAIRE Tel. 050-408576, Tlx. 385653 nordata fernv
U.S.A. Norsk Data N.A., Inc. 65, William Street Wellesly, MASS. 02181 Tel. 0617-237-7945
Sweden ND Norsk Data AB Klaringfagatan 11, Box 9052 421 09 VÄSTRA FRÖLUNDA Tel. 031-299350
France Norsk Data France 120 Bureau de la Colline 92213 SAINT CLOUD Tel. 01-6023367, Tlx. 201108 nd paris
England Richard Norton (NORD) Ltd. NORD House, 17 Balfe Street, King's Cross LONDON N1 9BE Tel. 01-2785501, Tlx. 299537

Note: Norsk Data reserves the right to change specifications at any time. It is our policy to improve products as new techniques and components become available.