JULY 2010 PRELIMINARY MANUAL

Transcription

1 Altair 8800micro Setup and JULY 2010 PRELIMINARY MANUAL Briel Computers 5392 Cornell Blvd North Ridgeville, OH 44039

2 All materials, schematics, and hardware designs provided without any warranties. Although this material has been carefully examined, Briel Computers takes no responsibility for any errors in printing. Version 1.0 Published by Briel Computers 5392 Cornell Blvd North Ridgeville, OH USA Copyright 2010 Briel Computers; All rights reserved. Printed in the United States of America. Except as permitted under the Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher, with the exception that the program listings may be entered, stored, and executed in a computer system, but they may not be reproduced for publication. Briel Computers 2010 page 2

3 Forward Recreating a cult classic Anybody who has been even remotely involved in vintage computers knows of the Altair There have been many discussions on the first personal computer, the first home computer, but nobody can argue that the Altair set the industry in motion. Original Altair 8800 system The original Altair 8800 was designed in 1975 by Ed Roberts founder of MITS (Micro Instrumentation and Telemetry Systems). Ed Roberts shown next to some of his Altair machines Briel Computers 2010 page 3

4 In 1977, Ed Roberts moved back to rural Georgia after the sale of MITS to Pertec. Nearby Mercer University started a medical school in 1982 and Ed Roberts went on to be the first graduating class and get his medical degree in He did his residency in internal medicine and in 1988 established his own practice. Ed Roberts died on April 1, 2010 after a long bout of pneumonia at the age of 68. The computer system he created was introduced to the world in the January 1975 edition of Popular Electronics and shall live on forever. January 1975 Popular Electronics featuring the ALTAIR 8800 The article describes the entire system of the Altair and took two issues to cover the entire system. The production version was not ready at the time and MITS had this case made for the magazine article. You could purchase an affordable base kit for $439 which included the case, CPU board and 256 bytes of memory. The assembled version was $621. Soon after the release Bill Gates sent Ed Roberts a letter stating he had a software company that had BASIC that would work on the Altair. Paul Allen came to MITS in Albuquerque to demonstrate their program using paper tape; it crashed after it displayed Altair Basic. The next day a new paper tape reader was brought in and BASIC loaded successfully. This was the beginning of Microsoft, the largest software company in history. Copies of BASIC were bundled with a pair of Altair 4K RAM boards for $75. However, the RAM boards were flawed and most users did not want those boards. Robert Marsh who formed Processor Technology offered 4K static RAM boards for $255. His company was the most successful company that produced Altair compatible products. This kept many hobbyists from wanting the flawed 4K MITS boards and the full retail price for BASIC from Micro-Soft was $500. The Homebrew computer club was formed in 1975 and the primary computer there was the Altair 8800 system. Steve Dompier passed a copy of the pre-release version of BASIC to Dan Sokol who had access to a high speed tape punch. The next day at the Homebrew Computer Club meeting, 50 copies of BASIC were made available to members for $.50 each. Shortly, many people had copies of BASIC and were passing it along freely. Word of this got back to Bill Gates and prompted this open letter to hobbyists in 1976: Briel Computers 2010 page 4

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7 The second letter was sent out to all major computer publications after a very strong negative response from many in the field. In late 1975 Imsai released the 8080 as a direct competing clone of the Altair. Most feel that the Imsai was a better machine than the Altair and used the same bus expansion scheme. It wasn t long before several other companies also had clones using the S100 bus system. This led to several aftermarket companies developing hardware add-on cards for the S100 bus systems. By 1977 MITS had reached $6 million in sales when they were sold to Pertec. The company was soon merged into the larger company (Pertec) and the name abandoned. The S100 bus system computers continued to be sold well into the mid 80 s and I remember as late as 1990 still seeing ads for S100 boards in magazines. The Altair 8800 is an icon for the start of the home computing industry. Long live the blinking lights :.::.: Vince Briel Briel Computers 2010 page 7

8 Setup and Index Chapter 1: Introducing the Altair 8800 micro 9 Chapter 2: Unpacking your system 13 Chapter 3: Building your kit with step by step instructions 15 Chapter 4: Powering up and testing your system 23 Chapter 5: Programming with the front panel 27 Chapter 6: Loading BASIC 29 Chapter 7: Saving memory to an SD card 30 Chapter 8: Loading a text file BASIC program listing 31 Chapter 9: On screen graphics and color 32 Chapter 10: Special front panel functions 33 Chapter 11: Performing a firmware update 35 Appendix A: Troubleshooting 75 Appendix B: The expansion port 80 Appendix C: Bill of materials 85 Appendix D: VT100 Control Commands 95 Briel Computers 2010 page 8

9 Chapter 1: Introducing the Altair 8800 micro The Altair 8800 micro is the result of 5 years of concept ideas and many failures. While the project spent much time on the shelf, the desired result would keep this project alive. The micro is based on a simple early version Altair 8800 with memory and a serial card for I/O. The project goal was to design a system that could be programmed like the original with toggle switches and could run the original Altair BASIC programming language. The micro is the first in a series of Altair clones that will be released. A full size version will be in the works after the initial release of the micro that will be a front panel only and then the original concept AltairPC. Final Altair 8800 micro prototype You may have noticed that not all of the original Altair I/O status LED s are on the front panel. This is due to the limited amount of I/O and the limited amount of physical space allotted on the front panel itself. The missing LED s are INTE, PROT, WAIT, and HLDA. In addition to the missing LED s one AUX switch was also not included on the board. The AUX switches were not directly used on the original Altair but the one AUX switch on the Altair micro serves as a boot loader and memory storage detector. Choosing a processor was no easy choice. Most replica computers created by Briel Computers use authentic processors that are identical to those used in the original systems. The Altair 8800 micro is different. The original processor (i8080) has multiple voltage requirements making design implementation difficult for kit purposes at a low price. The Z80 processor is very close to the 8080 and most code works with it. The problem is that it doesn t run Altair BASIC and was one of the failed concepts. This processor failure set the project back over 2 years. After considering using the 8085 (software compatible), I opted to emulate the CPU in a microcontroller. The main reason was chip reduction. With a microcontroller I am able to not only embed an emulated version of the 8080; I can also emulate most of the Altair system in 1 chip. The main CPU microcontroller has the nickname AOAC (Altair on a chip). While there are I/O pin limitations, a handful of latches can give you as much I/O as you need. Briel Computers 2010 page 9

10 Writing an emulator for a CPU is a very difficult process if you ve never written an emulator and you have very little programming experience on the CPU you are emulating. My first step was to learn about a CPU that I hadn t used in 20 years. Many CPU s share similar features such as accessing memory, having registers to work with, math functions, ability to call routines, jump to memory locations, etc. It wasn t long before I had a good handle on the CPU and how it functioned. The hardware is a simple design. Using the Atmel AVR family microcontroller was a simple choice. It is RISC based and many of the instructions only require one clock cycle to perform. The heart of the code simply reads a memory location OP instruction and handles that instruction exactly like the 8080 would. Some instructions were almost directly compatible to the Atmel instruction set making emulation easy. Other instructions were much more difficult and required more code to interpret the command. Single step introduced a whole other problem. Not only does the microcontroller emulate the instruction, it breaks it down into steps. As the original Altair single-steps through code, it does so one section of the instruction at a time. For example, a jump to another address command first gets the opcode, and then on the next step it fetches the low order byte of the address it is going to jump to. On the final step, it grabs the high order byte. The next step will place the CPU at the new address. With the core of the CPU and front panel emulation complete, the built on terminal section received its features. The terminal section is from the Briel Computers PockeTerm with a lot of changes. The addition of an SD card slot gives the ability to load and store programs and memory. SD card slot on Altair 8800 micro The SD card has the following features and conditions: Cards work with FAT16 or FAT32 only, no NTSF 8.3 filename format, no using long names Root directory access only, no reading/writing to subdirectories Micro-SD cards can be used with an adapter Cards must not be removed while the system is on The purpose of the SD card is to store and load BASIC, complete memory including BASIC and firmware updates. The card was not designed to load disk operating systems and other such means of storage. Modifications may be possible to do this in the future but not at this time. Briel Computers 2010 page 10

11 Altair 8800 micro VGA port The VGA output port is part of the terminal system. Consider all of the I/O ports as part of the terminal system and you will better understand how everything is connected. The VGA port gives the user an 800X600 display of 80X40 characters with a single color choice that can be modified on the keyboard. The cursor can also be changed from a blinking square to solid or underscore, blinking or not, or no cursor at all if you choose. Most monitors work just fine with this system, but it is software driven and not a hardware VGA driver so some monitors may have more difficulty syncing up with the system. We have found this to be a very rare occasion and you should have no issues with your monitor as long as it meets the system specs. When using the VGA monitor in BASIC, you may want to do some cursor controls such as, turn off the cursor and move the text location to X,Y. You can do these features using what is called VT100 commands. The VT100 commands are essentially code commands that tell the terminal section to perform a specific function. One example that is commonly used is the HOME CURSOR command: ESC[H To use this command in basic the code would look like this: 10 PRINT CHR$(27)+ [H ; This moves the cursor from wherever it was to the upper-left corner of the screen. Even if the cursor is off, the next character to be displayed on the screen starts printing there. Other functions can be found in the appendix section. Composite video connector Since the other video output choice is composite monitor, you can choose to use both setups at the same time if you wish with no issues. The composite video output port is a full color 40X25 NTSC output port capable of displaying full color characters with text block style graphics. You can turn on/off the cursor using VT100 codes as well as clear the screen, home the cursor and set X,Y location of cursor. Not all VT100 codes are capable with the composite output due to the smaller screen size and driver limitations. Briel Computers 2010 page 11

12 PS/2 keyboard port The ps/2 keyboard port gives the user the ability to use a standard PC style keyboard to type data into the system. The ps/2 port is also connected to the terminal section and any data from it is treated the same as a standard terminal. DC Power input jack The power input connector is a 2.5mm connector that accepts DC positive center connector. We suggest using a 1A (1000mA) 7-9V DC regulated power supply. If you connect the system with an incorrect power supply that has the + on the external connection, there is circuit protection up to 1A. The overall experience of the Altair 8800 mini will give the user a real life feel to what it was like to program a computer with lights and switches in the pioneering days of computers. Kit builders will find the experience of building a full system fun and rewarding. Briel Computers 2010 page 12

13 Chapter 2: Unpacking Your System Ok, you ve just received your Altair 8800 micro system, what do you do next? Well, if you purchased the kit, you will want to skip ahead to chapter 3 on building your kit. If you have the assembled system, we can guide you to getting it set up. What you need for your Altair 8800 micro: You can use a VGA monitor or TV with composite input. Use a keyboard that has the ps/2 connector on it. A USB converter may not work properly. The power supply needs to be at least 1000mA (1A) 7-9V DC positive center with a 2.1mm connector. You will need an SD card or you can use a Micro SD card with the adapter to SD. Briel Computers 2010 page 13

14 Prepare a space for your Altair 8800 micro: Make sure you have enough space to securely place a monitor behind your Altair. You can choose a CRT or LCD style monitor. If you find you need to place something under the monitor to raise it above the Altair, use caution that the monitor is stable and can not fall over. A good place for the keyboard is directly in front of the Altair or alongside the unit. Before you go any further, make sure the switch is up (off) on the on/off switch on the front panel. Connecting up a monitor: Using a monitor is optional, and you may wish to simply program the Altair from the front panel alone. In which case, you don t need a monitor connected. However, if you wish to run BASIC or another program requiring text output, you need to connect to a monitor. You have 2 choices to choose from on the Altair micro. You can choose a VGA monitor which gives you a nice crisp bold 80X40 text display of a single color choice, or you can choose a composite monitor or TV to get full multi-color text and low-res text graphics. If you can t make up your mind, that s ok, you can use both, and at the same time! My setup has a VGA monitor behind my Altair micro and a small 7 LCD TV that sits right on top of my Altair. Please use caution if you place anything on top of the Altair that it might not properly support the weight of your object. Plug in your keyboard: If you choose to use a keyboard for I/O, connect it to the PS/2 keyboard port in the rear of the Altair 8800 micro. Set it directly in front of the Altair with enough room to still be able to flip your switches. Plug in an SD card: If you are going to use an SD card to load/store programs, you must do this with the power turned OFF. WARNING: Removing or installing the card while the power is on could result in damage to the card or data loss. You may also use the newer micro-sd card but you will need to use an adapter for it to fit. Add some power: Using your own supplied power supply, plug the connector into the DC power connector port and plug the other end to a wall socket. Make sure your power supply is 7-9V DC 1000mA (1A) power supply with positive center supply. WARNING: If you attempt to use an incorrect power supply, you could damage the Altair 8800 micro. Please feel free to ask if you are unsure about your power supply or have any problems. You are now ready to use your Altair 8800 micro and begin your new adventure in old school computing. Briel Computers 2010 page 14

15 Chapter 3: Building Your Kit with Step By Step Instructions If you purchased your Altair 8800 micro as a kit, you will need to assemble it before you can begin programming. In order to assemble your kit, you will be required to solder the components onto the 2 printed circuit boards and mount the boards and panels in the case. We will demonstrate how to assemble the kit step by step. You are encouraged to follow these steps as we have studied the best possible method for assembly with the highest degree of success. Inventory your parts for the mainboard from the following list: PART QTY ATMEGA 8515 CPU CYPRESS SRAM 1 74HCT573 LATCH 8 PROPELLER CHIP 1 EEPROM 1 5MHz CRYSTAL 1 20MHz CRYSTAL 1 LM7805 VOLTAGE REGULATOR 1 LM3940 VOLTAGE REGULATOR 1 40 PIN SOCKET 2 28 PIN SOCKET 1 20 PIN SOCKET 8 8 PIN SOCKET OHM RESISTOR OHM RESISTOR OHM RESISTOR OHM RESISTOR 1 1K OHM RESISTOR 1 3.3K OHM RESISTORS 5.1uF CAPS 12 22pF CAPS 2 10uF CAPS 2 100uF CAP 1 1N4001 DIODE 1 PS/2 KEYBOARD CONNECTOR 1 RCA YELLOW VIDEO CONNECTOR 1 VGA CONNECTOR 1 HEADER CONNECTORS 3 SD CARD CONNECTOR 1 DC POWER CONNECTOR 1 SCREWS 6 NUTS 2 BLANK MAINBOARD PCB 1 Briel Computers 2010 page 15

16 Tools required for assembly: 1. Soldering iron or gun (25-35W preferred) 2. Solder (low temp solder works best) 3. Phillips screwdriver 4. Wire cutters 5. Old dry towel for cleaning iron Before you begin, make sure you have plenty of space to work with and have your components sorted into sections. The front panel and mainboard sections come bagged separately to help avoid confusion and to locate your parts quicker. Plug your soldering iron or gun in and allow the iron to get hot. Make sure nothing is around the tip that can get melted. Allow 5-10 minutes for your iron to fully heat up. Using a dry towel, wipe the tip clean of any old solder. If you are using a gun, you need to hold the trigger to heat up most units. I will refer to your soldering device as an iron from this point on. Tin your iron by melting a small amount of solder directly onto the tip of your iron. If your iron is hot enough the solder should melt with ease. Now, using your dry towel, wipe off the excess solder so that your tip looks solder shiny but with only a very thin coat on the tip. This helps transfer the heat to the contact area for a better solder flow. You are now ready to assemble the mainboard using the following steps: Step 1: Install the SD card slot. The SD card slot sits on the top of the PCB and there are 2 notches that should fit into holes so that it is perfectly sitting on the board. Carefully solder all of the pins to their pads. NOTE: Solder the 2 upper ground pads at each side of the SD card slot to the PCB Step 2: Install the resistors. Resistors are small cylinder shaped components with wire sticking out on each side. The colored bands identify the size of the resistor. Each resistor will have either a gold or silver band. Hold the resistor so the gold or silver band is on the right side. Now look at the first colored band on the left side. That color is the first digit of the resistor. Let s assume your resistor has the color band pattern Yellow, Violet, Red, and Gold. Looking at the chart on the next page you can calculate the value of that resistor. Briel Computers 2010 page 16

17 Resistor color chart The first color on the left is Yellow which equals the value 4. The 2 nd color is Violet which equals 7. The 3 rd color is red. This is your multiplier. Red equals 2 so we add 2 zero s to the end. So, the resistor value is or 4.7K. The gold band indicates that value will be within 5% of the value when measured. Find the 3.3K resistor. The 3.3K resistor has the value Orange, Orange, Red, and Gold. Bend the metal wire tabs at a 90 degree angle at the ceramic edges so the resistor forms a U shape. On the top side of your printed circuit board (PCB) locate a resistor spot for 3.3K and insert the resistor into the holes and make the resistor sit flat on the PCB. There is no polarity on the resistor so it does not matter which side gets inserted into which hole. While holding the resistor flat on the board with one hand, turn over the board and open up the wires so they point away from each other enough so that the resistor will not fall out. Set the board down on the table and place your iron tip on one side of the round ring hole and on the wire. Count to 5 then touch the other side of the hole with solder. Try not to touch the iron. Wait until the solder begins to melt and flow. Make sure you are only touching the ring and the resistor wire with the iron. Apply enough solder so the wire forms the shape of a triangle. At this point, remove the solder, then the iron. Check your work to make sure the solder adhered to the ring only. Now solder the other resistor wire and ring. Cut the extra lead wire off close to the PCB. Repeat with all the other resistors. I like to keep all my resistors facing the same way so that all the gold rings are on the same side. It does not make any difference if you do this or not, but try not to unsolder a component unless you have to. Please note that there is no resistor #15. R15 was removed from the design. Step 3: Install the Crystals The Crystals are like the heartbeat of a CPU. CPU s operate on timing and synchronization. There is one 5MHz for the Propeller CPU (terminal) and one 20MHz crystal for the ATMEGA8515 CPU. The numbers are clearly labeled on top and they can be installed in either direction. Like the resistor, install the wire leads until the component sits flush with the board. Hold the component, turn over the board and separate the 2 leads away from one another to help hold the crystal on the board. Now set the board down and solder the crystals to the board. Cut the extra lead length off. Briel Computers 2010 page 17

18 Step 4: Install the Diode. The diode is like the resistor in shape but it is polarized. You must install it so the white stripe on the diode matches the white stripe on the PCB. Bend the leads just like the resistors and push it flush onto the PCB. Turn over and solder down the leads and cut the extra length off. Step 5: Install the Sockets. Sockets are the host spot for the integrated circuits (IC s). One short edge will have a notch in it and the white silkscreen on the PCB will have a matching notch. This helps identify where pin 1 is on the chips. When installing the socket onto the PCB, make sure you match the notch up with the PCB drawing of the notch. Hold the socket flush on the board and flip the board over. Carefully set the board down so that the socket remains installed on the board. Solder two opposite corner pins and flip the board over and make sure that the socket is still flush on the board. If not, you can heat the pin up and push the socket flush. Solder the rest of the pins down. Repeat for the remaining sockets. Check your work before moving on. One of the biggest issues with kit building is missed solder spots. Make sure you solder every pin correctly. Step 6: Install 40 pin headers. There are 3 40 pin IDC.100 spacing headers on the mainboard. One is used for expansion; the other 2 are for connection to the front panel. The shorter side gets inserted into the PCB. Make sure it is inserted all the way, hold the connector and flip the board over. Solder one pin on each edge and check to make sure the header is still flush with the board. Finish soldering the rest of the pins. Double check all the pins before soldering the next header. There is no polarity on the headers and they can install in either direction. Just be sure that the longer leads are pointed up. Step 7: Install the ceramic capacitors. There are 12.1uF capacitors and 2 of the 22pF capacitors. Logically, there are 2 that are different from the others and that s the easiest way to tell the difference. They are not polarized so you can install them in either direction. You should be able to mount these flush with the board and then solder them down. Cut the extra length off of the leads after soldering. NOTE: C3 is missing on REV 0 boards so there are only 11.1uF capacitors Step 8: Install the DC Power Connector. Make sure the hole for the wall wart power supply is facing the edge of the board. It is easier if you bend the leads away from each other then flip the board over to solder them down. Briel Computers 2010 page 18

19 Step 9: Install the Composite Video Out connector. Make sure the yellow post portion is facing the edge of the board. Mount it flush and bend the leads to hold component in place. Flip the board over and solder down. Step 10: Install the PS/2 keyboard connector. When installing the PS/2 connector, take your time and get all the pins lined up correctly. Make sure the connector is flush with the PCB and flip the board over. Check to make sure you get all connectors soldered correctly with no solder bridges. Step 11: Install the VGA connector. This connector fits with ease onto the board. Be sure to check for bent pins before inserting into the PCB. Flip the board and solder all the leads including the two large mounting tabs. This will help hold the connector onto the PCB better. Step 12: Install the Electrolytic Capacitors. These capacitors are polarized and must be installed in the correct orientation onto the board or you will damage the capacitors and the board. Look at the large 100uF capacitor and you will see a (negative) sign on one side with an arrow. That is the negative lead and is the shorter lead. The other lead is the + (positive) lead and is longer. Insert the capacitor with the longer lead at the + marked hole on the PCB and push the capacitor flush onto the board. Flip the board over and solder both leads and cut the extra length away. Repeat for the 2 smaller 10uF capacitors. Step 13: Install the Voltage regulators. Voltage regulators convert voltage and supply a steady supply to the IC s. There are 2 of these and it is important that you do not get these mixed up or damage will occur to the board. One is labeled This one is closer to the DC power connector. Install through the 3 holes and then bend the regulator over so that it is laying down flat on the PCB. The hole should match up with the large hole on the PCB. Place one screw threw the hole and put one nut on the bottom side of the screw. Do not over tighten the screw. Solder the 3 leads and cut the extra lead lengths off. Repeat for the 3940 voltage regulator. Briel Computers 2010 page 19

20 Step 14: Install the IC chips. Find the chip labeled ATMEL ATMEGA8515. This is the main CPU chip of the Altair 8800 micro. One short edge will have a notch in it. Match the notch on the chip with the silkscreen or socket on the PCB and carefully install the chip. The machined sockets are going to give resistance to installing the chip so use caution not to bend the leads. If you do, remove the chip and straighten out the pins and try again. Repeat this step for all of the chips making sure to install them in the correct orientation. You are now finished with the mainboard and are ready to move on to the front panel. Inventory your parts for the front panel from the following list: PART # QTY 2 POSITION SPST SWITCHES 21 3 WAY MOMOMENTARY TOGGLE OHM RESISTORS K OR 3.9K OHM RESISTOR PACKS 3 HEADER CONNECTORS 2 RED LED's 32 FRONT PANEL PCB 1 SCREWS 4 While the parts list looks small, the front panel is much more difficult to build than the mainboard. The front panel PCB assembly will require the front panel plate to install the switches and LED s so they line up with the holes correctly. Find your bag with the front panel components and check your inventory. Step 1: Install the resistors. There are 32 resistors and they are all 220 ohm resistors. They are labeled RED, RED, BLACK, and GOLD. Install and solder them the same as the mainboard. Step 2: Install the resistor packs. These are polarized and must be installed in the correct orientation. Look for the small dot on the edge of the resistor pack. Match that dot with either a dot on the PCB or the same edge as the RPx label. Solder all the leads and double check your work. Briel Computers 2010 page 20

21 Step 3: Install the 40 pin headers. There are 2 40 pin IDC.100 spacing headers on the front panel PCB. Both are used for connecting switch and LED data to/from the mainboard. The shorter side gets inserted into the PCB. NOTE: The headers MUST be installed from the back side of the panel so they stick out the bottom (back) of the PCB. If they are installed incorrectly, your Altair 8800 micro will not function. Please notice picture below showing the headers mounted to the back side of the PCB. Inside photo showing front panel connecting headers located on back side of PCB Make sure it is inserted all the way, hold the connector and flip the board over. Solder one pin on each edge and check to make sure the header is still flush with the board. Finish soldering the rest of the pins. Double check all the pins before soldering the next header. There is no polarity on the headers and they can install either direction. Just be sure that the longer leads are pointed up. Step 4: Installing the switches. This is the tricky step. To make mounting and building easier, the front panel has PCB stand-off s mounted to it. When installing the switches, it is best to have the switches in the down position. There are 3 switches that are red and they are momentary switches. They go in the STEP, EXAM and DEP locations and are not outlined on the PCB. They go in the holes directly under the labels and are not polarized and can install either way. Set the switches in their location and place the front panel over the switches. If you can put the screws into the PCB and into the front panel plate without the switches falling out it will help keep the switches in the right angle but can still fall out of the PCB. Carefully turn the board over and set the board on the work bench so the toggles are resting on the table and pushed all the way flush with the PCB. Solder one pin on each of the 3 switches and remove the metal front panel. Check that the switches are still flush with the board and you can finish soldering the other 2 contacts from each switch. Install the blue switches in the remaining switch locations on the bottom row (STOP, RESET, PROT, and AUX). Notice that the STOP switch is oriented upside down from the other 2 pin switches. Use the front panel plate as needed to keep the switches lined up but remember that it won t keep the switches from falling out. You can now install the 16 upper row switches. Make sure that the switches line up with the holes on the front panel plate. Briel Computers 2010 page 21

22 Step 5: Installing the LED s. The LED s are polarized and have a + (positive) and a (negative) lead. The longer lead is the positive lead. Insert all the LED s so they are oriented with the longer lead going into the holes with the + symbol. Place the front panel plate back on over the switches and place the screws in the mounting standoffs. Turn the panel upside down so the metal front panel is on the bottom. One at a time, push the LED s so they go through the metal panel as far as they can. Solder down the LED s and cut the extra length off. NOTE: Take your time and do the LED s one at a time for the best results. Inspect your work and make adjustments to the LED s before cutting the leads off. You can now leave the metal panel connected to the front panel PCB. At this point both boards are completed and ready to install into the case. Inventory of parts to complete the Altair 8800 micro: PART QTY FRONT PANEL & PLATE 1 MAINBOARD 1 CASE 1 CONNECTING CABLES 2 MOUNTING SCREWS 6 REAR PLATE 1 The case has a top and a bottom. The bottom has a speaker port that is small round slots. To keep the cost low, we found a standard enclosure to use and had the front and rear panels made to fit the case. You may discard the blank black panels as they are not needed. Place the rear panel on one side and slide it down the slotted fitting. Take the completed mainboard PCB and set it down so it fits on the case and the VGA port and composite video ports go through their holes slightly. Screw down the six screws into their locations on the board. We have found that sometimes one hole is not opened up for a screw and that is ok, skip it and move on. Attach the data cables to the mainboard in locations CABLE 1 and CABLE 2. The cable has a red line on one edge indicating pin 1. You will notice on the board a number 1 on one corner of the header. Make sure the red edge matches up with the number 1 on the board. Plug CABLE 2 into the front panel header that is on the upper middle of the back of the PCB. Pin 1 is lightly labeled on the back on the left side of the header. When connected properly, there is no twist to the cable. Plug CABLE 1 into the other header on the front panel PCB that is mounted vertically. Pin 1 is on top so the red cable should be up at the top. There should be only a slight twist (half turn) on the cable. Slide the front panel PCB with plate into the case slot. NOTE: Double check your cables to be sure they are installed correctly. Installing the cables incorrectly could damage your computer. Now place the lid onto the front and rear panels and make sure they are going into the slots on the case. The case lid should go on without using any force. The 2 large case screws can now be installed. This completes the assembly procedures for the Altair 8800 micro. Any trouble shooting of the hardware will need to be done with the case open. Briel Computers 2010 page 22

23 Chapter 4: Powering up and testing Your System Before you power up your system, it is best if you prep a SD card to load BASIC from. Included on your CD is a copy of 8KBASIC. Make sure you have an SD card that is formatted in FAT or FAT32. Be sure to copy BASIC from the SD card over to the root directory of the SD card. If you try to use subdirectories, you will not be able to load BASIC. How to format an SD card: We will show you how to format an SD card using a Windows PC system. First, using Windows Explorer, find your SD card. In our case, it is labeled as Removable Disk (G). We are simply using the card reader on a printer to read from. The printer has several memory card slots and we are using one that is labeled SD MMC. WARNING: ALL data on the SD card will be erased. Be sure to backup your data first Briel Computers 2010 page 23

24 Right mouse button click on the drive that is your SD card and you will get a drop down (or up) menu of options. Move the mouse cursor over Format and left mouse select Format. Briel Computers 2010 page 24

25 When you select Format, you get a pop up box that will look like the picture above. First thing to look at is the Capacity. In our case, we are using a 4GB SD card. This is probably overkill, but it was a card we have laying around. The file system is FAT32 because FAT has a 2GB limit. We are also choosing the smallest Allocation unit size of 32KB to help ensure the card is readable with the Altair 8800 micro system. You can also see that Quick Format is selected. This is ok as long as the card will do a Quick Format. If Quick Format fails, unselect this box and do a full format of the card. Click on the Start button and format the card. You should do this because you may have a card that was formatted with a camera or other device and is not readable in the Altair micro. If you get this message you are finished formatting the SD card and can now put BASIC onto your SD card. Briel Computers 2010 page 25

26 Once you copy BASIC onto your SD card, remove the card and place it in the Altair 8800 micro SD card slot. With the SD card ready, plug in your VGA or composite TV/monitor. I use a 19 LCD VGA monitor for the VGA output and a 7 widescreen LCD TV for the composite. Choose the monitor that you feel is the best for you. Next, plug in your keyboard into the PS/2 keyboard port. Look for an arrow on the keyboard plug connector. That will be the top of the connector and should plug right in. Now you are ready for the power supply. First, make sure the power switch on the front panel is up in the off position. Plug your power supply connector into the port on the rear and plug it into your wall outlet. Before you start, make sure all switches 0-15 are down. To start the system so it will load BASIC, you must put the front panel switches in a specific mode. First, we need to put the AUX switch up so the system will know we want to load a file. With the AUX switch up, we need to flip up switch 11 so the system knows we are using the SIO onboard terminal system. With both AUX and SW11 up, we can now power up the system. At first, on the panel you should see INT status LED light come on. On your monitor it should display the Altair 8800 micro greeting message along with a prompt asking for a file name. If you do not see the INT light come on and no greeting message on your monitor after a few seconds, turn off the Altair micro and recheck all your connections. If you are going to load BASIC now and want it to run after it finishes loading, flip the RUN/STOP switch down to RUN so that the system will start running when loading is finished. If you get the prompt File name to load? then type in the name of the file of the version of basic you wish to load. In this example, we will load 8K BASIC, so type in 8KBASIC.BIN You will notice that you are typing in uppercase, that is ok, and the system will adjust automatically for the filename. If you make a mistake typing it in, there is no backspace, so you must turn off the system, wait a few seconds and turn it on and try again. If your file name is 8 characters long followed by a period and the file extension, it will not wait for ENTER to be pressed and will attempt to load the file. If you typed the name in incorrectly or it can not find the file, it will respond with Opening failed. If you typed in the name correctly and it finds the file, you will see the LED s on the address display start to go up. The system is now loading BASIC into the system. When it is finished, if you have the RUN/STOP switch down to the RUN mode, it will attempt to start BASIC. At this point you will see the message MEMORY SIZE? If you don t see this message and the RUN/STOP switch is on RUN, then BASIC failed to load correctly. At this point, you should turn off the Altair and start over. BASIC has the ability to check how much memory you have available. If you press ENTER BASIC will check how much memory you have available. The next question BASIC will ask is TERMINAL WIDTH? If you press enter, the terminal width default used, 80 is the screen width on the Altair 8800 micro. The last question asked is WANT SIN-COS-TAN-ATN? You must answer Y or N for this. If you choose N, you will not have trig functions available. If you are loading 4K BASIC, it will just ask WANT SIN? Choose Y and continue with ENTER You should now get the BASIC version info and an OK. You are now ready to program in BASIC. Briel Computers 2010 page 26

27 Chapter 5: Programming with the front panel The front panel on the Altair 8800 micro is very similar to the real Altair It has 16 data/address switches, 8 of which are called the SENSE SWITCHES. There are momentary switches to STEP, DEPOSIT and EXAMINE memory. Due to the size issue with the case, we decided to eliminate 4 LED s from the display as well as 1 AUX switch. As discussed in the next chapter, you can load BASIC at power up just by having SW11 and AUX up on power up. But what if you don t want to program in BASIC, you want to enter data just like it was 1976 again. You have a choice, you can load BASIC but not use it, or put the AUX switch down on power up and the system will not prompt for a BASIC file name. If the RUN/STOP switch is up in the STOP mode, you are ready to read/write to/from memory. Let s give it a try. Turn off your Altair and put all switches down except OFF and RUN/STOP. Turn on your Altair. If you have a monitor connected to the Altair you will notice that it does not ask for a file name. The LED s on your panel should be all off on the address row and your status LED s and DATA LED s will be lit. If there is no DATA LED s lit (D0-D7) that means at address 0 the value 0 is stored. Let s put the value $80 at location $0001 in memory. Step 1: Lift address switch 0 Step 2: Lift and release EXAMINE switch (A0 LED will now be lit) Note: At this point there may be data at that address; we are going to write over it Step 3: Push down switch 0 and lift up switch 7 Note: Switch 7-0 are now being used as your data input value by lifting switch 7 only that is the value $80 Step 4: Lift and release DEPOSIT switch Your address LED s should display A0 lit and D7 lit, this indicates that at memory location 1, the value or $80 is now stored at that location. Briel Computers 2010 page 27

28 Ok, now you know how to store data in memory, but there is a slightly quicker way. What do you do when there are several bytes you need to program all in the same block of memory? DEPOSIT NEXT will deposit your data in the current memory location, the auto advance to the next memory location. So, if you were to do step 4 over again: Step 4: Press down and release DEPOSIT switch Now the system deposits $80 to memory location 1 and advances to memory location 2. This makes programming quicker because now you only have to enter that DATA values and the system will keep track of the memory location. To check multiple memory locations in a row is very similar. Enter into the address switches the starting memory location to look at. Now lift up the EXAM switch. The D0-D7 LED s will now display the value of that memory location. Now if you push DOWN on the EXAM switch you will notice the address will change to the next binary address and the data will change to the value at that location. RESET is used when you need to reset the system from being locked up or in a HALTSYS state. When you press RESET it will restart the CPU, not the terminal section. This is important because if you have the AUX switch up and switch 11, it will wait for a terminal response to receive BASIC. If you already have BASIC loaded and working, then you can simply put AUX down as well as all the address switches. When you RESET it will start at memory location 0 which is the starting point for BASIC. There may be times when doing a RESET could erase a byte in memory and you will then need to reload BASIC. Briel Computers 2010 page 28

29 Chapter 6: Loading BASIC The Altair 8800 micro has the ability to run 4K or 8K BASIC as of the writing of this manual. Other versions may work with time. To load BASIC, you must do this from a power up stage. The reason is because you must have the terminal section restart to be ready to send BASIC from the SD card. Step 1: Prepare your card. Format and prepare your SD card with a version of BASIC loaded onto the card. With the power turned off on your Altair 8800 micro, place the card in the SD card slot on the back. Step 2: Prepare your front panel. The terminal section of the Altair 8800 micro and Altair BASIC looks to see what port to use BASIC from. Turn off all address switches, then lift only switch 11. Step 3: Lift the AUX switch and make sure PROTECT is down. Step 4: Push the RUN/STOP switch down to RUN mode Step 5: Turn on Altair 8800 micro At this point it will now prompt you for a file name to load. If you do not see a file name prompt on your screen (VGA or TV), then you may see an error about the SD card. Check your card and try again. Type in the name of your file and press ENTER. If your file name is 12 characters long, it will auto continue without the need for ENTER. NOTE: There is NO BACKSPACE for the feature. If you perform a typo, you must power up the system again. If you entered the file name correctly the terminal will start to load BASIC and send it to the CPU section of the Altair 8800 micro. As the data is being entered into the system, you will see the address lights cycling up and the DATA lights will flow with data. This is normal. When the file is finished loading you should get your Altair BASIC prompt messages on screen. If you don t, check to make sure the RUN/STOP switch is down to the RUN position and that only switch 11 is in the up position. If you still don t get the BASIC prompt, you may have a failed load and will need to power off and restart the process. When you enter your terminal screen width and other info you will get the version of BASIC you loaded along with the OK prompt. You are now ready to program in BASIC. NOTE: Do not remove the SD card while the power is on, doing so could damage the card contents Briel Computers 2010 page 29

30 Chapter 7: Saving memory to an SD card Now that you have had the chance to use the Altair 8800 micro, you may need to save your work. The SD card slot is connected to the terminal section of the system and the data from the Altair needs to be transmitted from memory to the SD card. To do this, we must enter memory record mode. With the system STOPPED make sure AUX and PROTECT are raised. Now, lifting the STEP switch will put the system in memory record mode. It will now prompt for a file name to store the memory to. Enter a file name with the 8.3 format. In other words, you MUST use a file extension. NOTE: Failure to use a file extension like.bin will cause that file to be stored in an unreadable format. You will not be able to delete that file from the card and the only way to remove it would be with a format from your computer. If you already had a file with the same name on the SD card it will automatically replace that file with the new one. There is no prompt for this, so be aware of your file name before saving. At this point, all of the memory in the 32K range is being stored to the SD card. This takes about 30 seconds to perform and then the system goes back to being able to be programmed. You will get a message on the screen stating that memory was saved to file name xxxxxx.xxx You can now push the PROTECT switch down and resume programming on your Altair 8800 micro and your memory contents are stored in the file on the SD card. To read the memory back, you do this from the power up stage just like loading BASIC. If you have a BASIC program you wish to store, you would simply lift the STOP switch right from BASIC, then perform the memory record function described above. When powering up the system, your new file will contain BASIC and the program you had in memory when you recorded it to the file. Briel Computers 2010 page 30

31 Chapter 8: Loading a text file BASIC program listing The Altair 8800 micro terminal section has the ability to dump text files into the system as if you were typing them in. This makes loading programs from a text file convenient and easy. Prepare your SD card with a text file of a BASIC program that you wanted entered into the system. Place the SD card into your Altair 8800 micro computer SD card slot. Before you begin, you must power up your Altair 8800 micro with a version of BASIC loaded and ready to go. When you are at the command prompt in BASIC, type NEW and press ENTER. On your PS/2 keyboard, press control and F1 at the same time. Now you will be prompted for the name of a file to load. Type in the file name and press ENTER. NOTE: There is no backspace feature in this routine. If you make a typing mistake, you will have to restart the process over Once the file is found and loaded, the terminal section will begin transferring the file over to BASIC as if it were keystrokes. You will see the program being entered on the screen. It is not very fast and is subject to errors but it is a good tool for getting programs entered. When the file is finished loading, you may wish to save it to the SD card by storing memory command for faster load times. Briel Computers 2010 page 31

32 Chapter 9: On screen graphics and color While the VGA monitor gives us a nice crisp 80 column display, it only has the ability to display a single color of text on the screen at a time. The composite TV output however has the ability to have a different color for any character on the screen. This gives the user the ability to create simple low resolution color graphics on the display. The VT100 control codes can be used in BASIC to not only change text colors but to locate the cursor anywhere on the screen or clear the screen. Example: 10 REM CHANGE TEXT COLOR WITH CHOICE OF REM WE WILL USE COLOR #3 30 PRINT CHR$(27)+ [3T 40 REM CLEAR THE SCREEN 50 PRINT CHR$(27)+ [2J 60 REM MOVE THE CURSOR HOME UPPER LEFT 70 PRINT CHR$(27)+ [H ; 80 REM MOVE CURSOR TO Y,X ON A SCREEN OF 40 BY 25 ON TV 90 PRINT CHR$(27)+ [12,20H ; 100 REM PRINT AN X ON THE MIDDLE OF THE SCREEN 110 PRINT X ; 120 END This is just a small sample of using VT100 commands to put characters where you want on your screen. Please refer to Appendix D for a full listing of VT100 codes. Keyboard function keys: The Altair 8800 micro terminal section utilizes function keys F1-F5 for special features. This is the list of features: CTRL-F1 CTRL-F2 CTRL-F3 CTRL-F4 CTRL-F5 SEND A TEXT FILE TO BASIC CHANGES TEXT COLOR (HOLD FOR CHANGE) UPDATE TERMINAL FIRMWARE TURNS ON/OFF BACKSPACE MODE* CHANGE CURSOR TYPE BLOCK, UNDERSCORE, BLINKING * Altair BASIC uses _ to simulate a backspace. The Altair 8800 micro terminal uses the backspace key to simulate this function. You can turn it on/off with CTRL-F4. Briel Computers 2010 page 32

33 Chapter 10: Special front panel functions Having a front panel gives the operator the ability to control the system. Everything from programming memory, to performing firmware updates. Here is a list of the current special front panel functions and the conditions to use them. Boot loading a file: This is the power up sequence that is used to load BASIC or other custom saved file programs. To use this setup you must have a binary (.bin) file stored on an SD card installed in the SD card slot with the power up. Place address switch 11 up and the other 15 switches all down. Turn up AUX switch and make sure PROTECT is down. Now you can power on the Altair 8800 micro to begin the boot loading procedure. The boot loader will prompt you for a file name. You must enter a file name using standard 8.3 naming procedure. For example: 8kbas.bin NOTE: There is no backspace when typing in the filename. If you make a typing error, you must power down the unit and start over Once the file name is found on the SD card it will begin loading the file into memory. You will see the memory location lights increasing until the entire file has been loaded or 32K reached. Backing up memory to a file on the SD card: Use this front panel feature to backup your memory at any time. The backup feature will backup all of the lower 32K of RAM including BASIC and BASIC programs if entered into memory. Lift the STOP switch so the CPU is stopped. Lift AUX and PROTECT switches so they are both up. Lift STEP and release to enter memory storage mode. At this point you will be prompted to enter a file name to store the memory to. NOTE: It is important that you enter a file name extension otherwise it will create a file that you can not access or delete. One example name is: memory.bin NOTE: There is no backspace when typing in the filename. Use caution when entering the filename. Make sure to use the standard DOS 8.3 file naming scheme. Once the file is stored, you can lower the PROTECT switch and continue programming. Briel Computers 2010 page 33