Nubus Graphics Card Theory Of Operation

NuBus Graphics Card Theory of Operations Toby Farrand Advanced Development Group Computer Graphics Lab 12 August 1986 - ! , NuBus Graphics Card Theory of Operations Toby Farrand Updates to the Specification • This specification applies only to the DVT version of the NGC labeled 1.0. • The CLUT register spaces have moved. • No reads of the card's control of status bits are supported. • The configuration ROM is now lK bytes. • A section on debugging of the card has been added. 12August1986 1 Apple Confidential NuBus Graphics Card Theory of Operations Toby Farrand Table of Contents 1.0 2.0 Overview 3 1.1 Features 1.2 -Cost 3 3 Software Interface 4 2.1 Memory Map 2.2 TFB Operation 4 5 2.2.1 TFB Register Values 2.2.2 TFB Initialization 3.0 5 7 Hardware Description 3.1 3.2 3.3 3.4 7 NuBus Interface Timing Generation Frame Buffer Video Output 8 8 8 9 4.0 Schedule 9 5.0 Debugging 9 6.0 Final Board Features 11 7.0 Layout 12 8.0 Schematics 15 9.0 PAL Equations 24 10.0 Timings 27 11.0 Bt453 Specification 29 12 August 1986 2 Apple Confidential NuBus Graphics Card Theory of Operations 1.0 Toby Farrand Overview The NuBus Graphics Card (NGC) is a high performance, flexible and low cost color graphics card for any Apple NuBus based product The card is based on the TFB frame buffer controller chip designed in the Advanced Development Group, and is targeted for introduction with the Milwaukee machine. 1.1 Features The NOC features variable color depth operation of either 1,2,4 or 8 bits per pixel with a color lookup table providing a palette of 16M colors driving 8 bit DACs for each of the ROB channels. The card is capable of generating proper timing for the Milwaukee monitors, or any RS 170 compatible monitor. (This includes such things as analog film recorders and projection TVs.) The board features high performance -- 400ns reads and writes from the NuBus interface. 1.2 Cost The board is expected to cost no more than $110 for the 512K byte version capable of supporting up to 8 bits per pixel color. A cost breakdown is given below: ITEM APPLE PART PART DESCRIPTION NUMBER ---- -------- QUANTITY PER BOARD EST. UNIT COST PART COST PER BOARD ---------------------- ---------- ---------- ----------- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 TFB (Apple Custom) NEC video RAM µPD41264150ns PAL16R4B 15ns PAL PAL 20R6A 25ns PAL Brooktree Bt453 CLUT/DAC Chip 2716 16K EPROM 74F153 Dual 4:1 MUX AM29841 Ten Bit Latch 74F521 Octal Comparator 74F245 Octal Buffer 74FOO QUAD NANO Gate 74F38 QUAD NANO Gate HY5030-100 Tapped Delay Line 12.2727 MHz Oscillator 30.2400 MHz Oscillator 96 Pin NuBus Connector D-Shell 15 pin connector LM385-1.2 Voltage Reference .1 µF Decoupling Capacitor 10µF Bulk Capacitor Ferrite Bead Resistor SIP Pack 10 pin 22 ohm Resistor, 3.3K ohm 5% Resistor, 47K ohm 5% Resistor, 75 ohm 5% PC Board, 4 layer 4" X 13" 1 16 1 1 1 1 1 1 1 14.50 3.00 1.75 1.7…