Atari ST System-on-Chip in VHDL - Atari Documentation Archive

121 Pages·2008·3.91 MB·English

Atari ST System-on-Chip in VHDL

Individual Project
UFEEJ4-40-3

Author: Lyndon Amsdon
Student Number: 05500164

Word Count
15116
Table of Contents

Paragraph Number Title Page Number

Chapter 1 - Introduction

1.1 Preface 1-1
1.2 Introduction 1-1
1.2.1 TV Boy 1-1
1.2.2 Flashback 2 1-2
1.2.3 NOAC 1-2
1.2.4 MSX Bazix 1-3
1.2.5 Minimig 1-3
1.2.6 C-One/C64DTV 1-4

Chapter 2 - In Depth Introduction

2.1 Atari History 2-1
2.1.1 Atari ST Models 2-1
2.2 Atari ST Hardware 2-2
2.2.1 MC68000 CPU 2-4
2.2.2 GLUE custom semiconductor 2-4
2.2.3 MMU custom semiconductor 2-5
2.2.4 SHIFTER custom semiconductor 2-5
2.2.5 DMA custom semiconductor 2-5
2.2.6 MFP MC68901 2-6
2.2.7 Yamaha YM2149 2-6
2.2.8 ACIA MC6850 2-6
2.2.9 FDC WD1772 2-6
2.3 Atari ST Operating System 2-8
Paragraph Number Title Page Number
2.3.1 Atari ST Boot Up Operation 2-8

Chapter 3 – Research

3.1 FPGA 3-1
3.2 Base Hardware 3-2
3.3 IP Cores 3-3
3.4 Software Suite 3-3
3.5 Processor 3-3
3.6 Books and literature 3-4
3.7 Debugging 3-5
3.8 Operating System Versions 3-6
3.9 System Memory 3-7
3.10 Serial Port 3-8
3.11 Video Output 3-9

Chapter 4 – Design

4.1 Components 4-1
4.1.1 Base Hardware 4-1
4.1.2 MC68SEC000 CPU 4-2
4.1.3 Static RAM 4-3
4.1.4 Debugging 4-3
4.1.5 OS and Flash Memory 4-4
4.1.6 5v PCI I/O 4-5
4.1.7 VGA 4-5
4.1.8 Floppy Disk Drive 4-6
4.1.9 RS232 Serial 4-7
4.1.10 Keyboard and Mouse 4-8
Paragraph Number Title Page Number
4.2 Design Differences 4-8
4.3 Process of Implementation 4-11

Chapter 5 – Implementation

5.1 Flashing LED 5-1
5.2 VGA Colour pattern 5-1
5.3 Writing bytes to Flash Memory 5-2
5.4 Writing file to Flash Memory 5-5
5.5 CPU 5-5
5.6 Reset 5-6
5.7 Clock 5-6
5.8 Synchronous Bus interface 5-7
5.9 Flash data bus resizing 5-8
5.10 7 Segment Display 5-9
5.11 Single Step 5-10
5.12 Glue IP core 5-10
5.13 MMU IP core 5-13
5.14 Hardware Breakpoint 5-16
5.15 Shifter IP Core 5-17
5.16 MFP IP Core 5-17
5.17 ACIA IP Core 5-19
5.18 YM2149 IP Core 5-20
5.19 DMA IP Core 5-21
5.20 FDC IP Core 5-22
5.21 Eiffel PS/2 Conversion 5-24
5.22 IDE Compact Flash 5-26
Paragraph Number Title Page Number

Chapter 6 – Testing and verification

6.1 Benchmarking 6-z
6.2 Colour Palette 6-z
6.3 Sound Techniques 6-z
6.4 Software Over Scan 6-z

Chapter 7 – Future ideas

7.1 Floppy Drive Emulation 7-1
7.2 MIDI 7-1
7.3 IDE 7-2
7.4 Unification of mass storage 7-2
7.5 Reconfigurable systems 7-3
7.6 Commercial viability 7-3

Chapter 8 – Summary

8.1 Summary 8-1
List of Illustrations

Figure Number Title Page Number

1 TV Boy 1-1
2 Flashback 2 PCB 1-2
3 NOAC SOC 1-2
4 MSX Bazix Unit 1-3
5 Minimig PCB 1-3
6 C64DTV 1-4
7 Atari ST CPU Prototype 2-2
8 Atari STfm Motherboard 2-3
9 Atari ST boot up sequence 2-7
10 Xilinx FPGA block layout 3-1
11 Flash memory organisation 3-6
12 DAC using resistor ladders 3-9
13 Specialised video DAC 3-10
14 Enterpoint Raggedstone 4-1
15 VGA video timing 4-5
16 RS232 to TTL level translator 4-7
17 ATX pin description 4-9
18 Design Block diagram 4-10
19 Architecture for LED Flash 5-1
20 Colour test display 5-2
21 Flash Programmer menu 5-2
22 MCS file format 5-5
23 Synchronous bus interface 5-8
24 Flash state machine 5-8
25 7 segment display 5-9
26 Address decoding in Glue 5-11
27 MC68000 start up sequence 5-11
Figure Number Title Page Number

28 SRAM and adapter PCB 5-13
29 Refresh Address removal 5-13
30 Refresh RAS removal 5-14
31 SRAM signal creation 5-14
32 Single Step DTACK creation 5-16
33 Photo of Desktop 5-18
34 Xilinx ISE DLL error 5-18
35 PWM Sound 5-20
36 Excerpt from OS 5-22
37 FDCSn from wf25913ip_ctrl.vhd 5-22
38 T1_VERIFY_CRC state 5-23
39 WD1772 delay state 5-24
40 Playstaion controller protocol 5-25
41 Degas Elite 6-1
42 Change to Shifter 6-2
43 SND Player 6-3
44 Envelope Shapes 6-3
45 Old enveloper generator 6-4
46 New enveloper generator 6-4
47 Screen borders 6-4
List of Tables

Table Number Title Page Number

1 Atari ST models 2-2
2 Xilinx development boards 3-2
3 MC68000 family processors 3-4
4 TOS versions 3-6
5 Serial port pin description 4-7
6 Flash memory commands 5-4
7 FPGA connections to 7 segment display 5-9
8 Start of Operating System 5-11
9 Memory Configuration register 5-16
10 IPL Encoding 5-18
11 Playstation controller packet 5-24
12 Colour palette error 6-2
Chapter 1
Preface
1.1
Within this personal project is a complete guide to the research, development,
implementation and conclusions to creating a System on Chip, based on the Atari ST
series of home microcomputer which spanned a production date of 1985-1993 [1]. The
project is designed to be left open to continual work and extensions beyond the original
Atari ST design.

This document assumes prior knowledge of Microsystems design and the Motorola
MC68000 CPU, and going in depth into these topics is beyond the scope of this
document.

Introduction and Overview
1.2
This project is inspired by other enthusiast’s attempts at creating systems on chip that
faithfully reproduce early home microcomputers and arcade machines. The development
in the last few years in programmable logic devices, with increased logic elements and
low development costs, has meant it is possible to fit entire computers into one
semiconductor.

1.2.1
TV Boy
One of the first commercially available products has to
be the ‘TV Boy’, which was an unlicensed reverse
engineered copy of the Atari 2600. It first went on sale
around the mid 1990s. The original Atari 2600 used
4Kbyte game cartridges whereas the TV Boy used a
Figure 1 - TV Boy
512Kbyte ROM as storage for the 127 internal games [2]. A spare 4Kbyte slot was used
as the game menu selection. As it was unlicensed by Atari the games had different
names and some had very small changes to the graphical details. All the digital
electronics were designed into a single ASIC, intended for mass production and low cost.

1.2.2
Flashback 2
There have been some official
licensed Atari consoles recreated
in modern silicon. The Flashback
2 is another Atari 2600 with 40
games included. The design of the
case is reminiscent of the original
Atari 2600, but being somewhat
Figure 2 - Flashback 2 Main PCB
smaller and lighter. The Flashback
2 was designed by Curt Vendel and Legacy Engineering, and in an interview Curt Vendel
remarked that the "Flashback 2 did exceptionally well with 860,000 sold in the
U.S./domestic" [3].

1.2.3
NOAC
Another unlicensed reversed engineered copy of a console
exists, based on Nintendo’s NES (Nintendo Entertainment
System). These are known as NOAC (Nintendo On A Chip)
and originate from a variety of manufactures in China and are
inaccurate in many ways to an original NES [4]. The Integrated
Circuit is supplied without a real physical package, instead being
Figure 3 - NOAC SOC
covered with an epoxy glue material.