Briel computers Replica 1 plus User manual

replica I

plus

Setup and Users Manual

JUNE 2014 PLUS EDITION

Briel Computers

Replica 1 plus Users Manual

All materials, schematics, and hardware designs provided without any warranties. Although this material has been carefully examined,

Briel omputers takes no responsibility for any errors in printing.

Version 3.0

Published by Briel omputers

13465 amino anada Suite 106-114

El ajon, A 92021

USA

opyright 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.

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Replica 1 plus Users Manual

Forward

How the repli a 1 ame to be

Thank you for purchasing your replica 1 computer. I take pride in every kit and assembled replica that is

shipped and my goal is that all kits and assembled boards work as designed. In early 2001 I was an avid

collector of vintage computers. I had started with an Apple IIe because it was close to my first computer the

Apple II plus. I, like many people who get the urge to relive the vintage years of computing looked to eBay to

find my past. After receiving my first computer I found myself wanting a monitor, a disk drive, anything to

make it fully functional. I didn’t just want a mantle piece; I wanted to actually use my vintage machine.

After spending some time with my Apple I remembered other computers I had seen in magazines but couldn’t

afford at the time. I little searching and I was able to start a nice little collection of home computers. I was

addicted to vintage computing and collecting everything I could get my hands on.

I was really proud of the fact that every machine I owned, not only worked but I had software to run on them. I

was fast becoming an expert in the area of software conversion from the modern computer realm back to actual

vintage media like 5 ¼” disk.

Feeling proud that I had a nice collection going I stumbled upon the www.applefritter.com website. I felt pretty

versed with apple II hardware and I noticed a small forum there and poked in to read some of the posts. I didn’t

see anything out of the ordinary but I noticed a subject right above the Apple II section labeled Apple I. Well, I

had never seen an Apple I and had only herd the stories like most people about how Woz and Jobs started Apple

omputers from their garage. I had to read more.

I quickly learned that only about 50 Apple 1’s remained in existence from about 200 boards and they were

highly collectable and way out of my price range. I read a post where people talked about making a replica but

nobody was really stepping up to the plate. I have an education in engineering so I decided to take a look into

the Apple 1 hardware.

In March 2002 I wrote to the Applefritter forum requesting some information on the Apple 1 and I informed the

group of my intentions. I was well received and many former and current owners of Apple 1 computers gave me

information and documentation to get started.

With manuals and emails from owners in hand, I looked over every inch of the Apple 1. I quickly decided not to

use all the original components from the Apple 1 due to their lack of ability. Although there are chip suppliers

that carry surplus components, their prices and minimum orders are just out of the question. This left me with a

decision that many people questioned. I could have made the replica 1 look like the Apple 1 but in the spirit of

Woz, I choose to go with more modern components and reduce the chip count as low as possible.

I quickly found that I could interface 32K of RAM with no address decoding. Simply using Address line A15 as

the select line, I could activate the RAM chip with A15 off. So, if the replica 1 was looking anywhere in the

address range 0000-7FFF A15 would be low and RAM chip select activated. If the replica 1 was looking at

address range 8000-FFFF A15 would now be high and the RAM chip select would be deactivated. I added some

logic so that the access time of the RAM write cycle was only during PHI2 of the 6502’s clock. For this I used a

74LS00 NAND gate I . I needed to invert the R/W signal and AND in PHI2. This required 2 of the 4 NAND

gates in the I .

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Replica 1 plus Users Manual

My next step was to add some address decoding so the replica 1 accessed the I/O chip 6821 PIA and ROM at

the same addresses the Apple 1 used. I used a 74LS138 to decode addressing for both the 6821 and an 8K

EEPROM. I also made sure that the space for BASI (E000-EFFF) was EEPROM so BASI could be stored in

ROM.

I now had a core PU section replicated from the Apple 1. I still had no video section and I needed to build a

prototype. After some delays I finally built a prototype on wire-wrap and tested it. It didn’t work. I needed to

troubleshoot the board but my free time was very hard to come by and the replica sat on the shelf for a few

months.

In November of 2002 I received an email from Leander Kahney of Wired Magazine. He had been reading on

the replica project and wanted to interview me. My first reaction was, “Why me?” I had no idea the cult

following that Apple had. I really was fond of Apple since the beginning but Apple has such loyal owners and

they love everything that involves the history. So, here I am on the phone with Leander as he is asking me

questions about why I am doing the project, and when will it be completed and what will I be selling these for?

What? I didn’t have the heart to tell him that the project is on the self, that I have no idea what to sell these for

even if I had a working version. Little did Leander know that because of him, the replica 1 was pulled off the

shelf and completed. I started from scratch, and created a breadboard version of the replica 1. This time it

worked… Sort of… Well, the I/O chip, the 6821 was sending binary code for a “\” which means that the replica

was seeing a reset and the Woz monitor was trying to output a “\” to a TV monitor. Now I needed a video

solution.

Right after the Wired article was released, I received an email from Greg Glawitsch. He stated his interest in the

project and said that he had a “down and dirty” solution to the video problem. His answer was to use a

microcontroller to output TV text like the video terminal section of the manual. He offered to help by writing

the firmware to do this and it would only require a couple external I ’s to help the microcontroller. Wow, 3

chips to do what took about 24 on the Apple 1. This was perfect. And with some work with Greg, we had a

working video section.

In August 2003 the first of the replica prototypes were being made. I didn’t have a name for the board yet and

simply called it A1 replica. I also just put my initials on the board with the year 2003. Shortly after my first

prototypes were built, I created Briel omputers. At this stage my old high school friend hris contacted Woz

through his webmaster asking for permission to use the Apple 1 code. His approval of the project prompted

another Wired article.

In October 2003, the first replica 1’s was being built and thus completing a 20 year old dream to design and sell

my very own computer. Thanks to Woz for being such a strong influence and great guy to give the ok for this

project.

Over ten years have now past and the replica 1 continues to evolve with new power supply connections,

different controller for video and other enhancements but the core machine is the same as it was from the

beginning.

Vince Briel

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Replica 1 plus Users Manual

Setup and Users Manual

Index

Chapter 1: A Brief History of the Apple 1

Chapter 2: Introdu ing the repli a 1 plus

Chapter 3: Unpa king and Setting Up

Chapter 4: Assembling Kit Version

Chapter 5: Programming the repli a 1

Chapter 6: Using The USB to Serial Interfa e

Chapter 7: Using the Krusader Assembler

Chapter 8: Troubleshooting your repli a 1

Appendix A: ASCII Keyboard Pin Out

Appendix B: Repli a 1 Memory Map

Appendix C: Monitor Listing

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Replica 1 plus Users Manual

Chapter 1: A brief History of the Apple 1

Steve Wozniak had designed and built many different little projects before the Apple 1 computer. The Apple 1

was not even his first computer design. He had designed the “cream soda computer” long before the Apple 1.

He had even designed a TV terminal that could be hooked up to a mainframe computer using a keyboard and

your TV as the display. Of course he also built the infamous “blue box” so people could phone phreak and

make free long distance calls. It wasn’t until Woz decided to combine two projects, and make one complete

computer never seen on the market before. He designed a single board computer and combined his TV terminal

to create what is today known as the Apple 1 omputer. He first presented the project to the Homebrew

omputer lub and it was well received. At that time, the only major computer out there was the Altair 8800

and that only came with LED’s and switches. The Apple 1 had a keyboard and a monitor. When he showed this

to his friend Steve Jobs, Jobs was excited and immediately wanted to make more to sell.

Figure 1: A tual Apple 1 Computer

In April 1976, Steve Jobs and Steve Wozniak decided to start Apple omputer ompany. It was based on a

computer design that Wozniak had completed making a computer that could display text on a TV and use a

keyboard without any additional boards. One board could do all of this. While it wasn’t the first home

computer, it was the first to give you all of these features on one board without any addition hardware. No

entering code by flipping switches and looking at LED’s. You could actually sit down at a table and type code

into the computer using a standard keyboard. Steve Jobs saw something great in this project and was eager to

start selling these boards.

Woz distributed schematics and source code listings for the Apple 1 computer at the Homebrew omputer lub

meetings in Northern alifornia bay area. Steve Jobs knew that there was enough interest in the boards at the

Homebrew club to sell boards to the members. 200 boards were printed and most of them were assembled but

not all of them. They assembled boards at night in Job’s parents’ garage and sold some to the Homebrew lub.

It wasn’t until a local computer store purchased $50,000 worth of boards that anything significant had

happened. After that, things changed.

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Replica 1 plus Users Manual

They knew they had a great product and that the average person could have a computer on their kitchen table.

Woz quickly worked on a BAI for the Apple 1 but it still lacked a means of storage. Shortly after the Apple

1’s release, Woz designed a cassette interface simply named the A I (Apple assette Interface). This interface

allowed the user to store programs onto an audio tape using simple 1 and 2Kh signals to store the data.

While the new interface was being designed and BASI was being written, the end of the Apple 1 was already

near. Woz was already working on the next version of his design. While many people thought the Apple II was

the same as the Apple 1 with just more features, the Apple II was a completely new design from scratch. This

new design could do color and using processor accessible RAM; you could do graphics and more. While this

was all being designed, the Apple 1 was still being made and sold.

BAI was finally released and that gave the Apple 1 a high level language for people to program in. This BAI

was not only written for the Apple 1, but it was also written for the Apple II at the same time. As a matter of

fact, if you look at a disassembly of the Apple 1 BAIS you will see some commands built in that are

impossible to perform, such as OLOR. There was no color graphics on the Apple 1, only text.

As soon as the Apple II was release, Jobs wanted to get rid of all the Apple 1 computers. He offered deals, like

half off an Apple II with the trade in of your old Apple 1. He so wanted to get rid of the Apple 1, that rumor has

it, he even gave some Apple II’s for even exchanges. Some he handed to engineers and programmers at Apple

to use, others he chopped up with a band saw. So, while there were 200 boards made from the board house, not

all were assembled and many were destroyed on the exchange program.

Today, approximately 50 Apple 1’s are known to exist making it one of the most sought after vintage

computers. Some auctions have fetched upwards of $50,000 for an Apple 1 but the average selling price is

around $150,000.

Figure 2: Steve Jobs and Steve Wozniak shown with an Apple 1 omputer in 1976

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Replica 1 plus Users Manual

Chapter 2: Introdu ing the repli a I plus omputer

The replica 1 computer was designed to give those people a chance to see what an Apple I computer looked and

acted like. Most people have never seen an Apple 1 running and the replica 1 helps us see what Woz had

created. The goal of the replica 1 project is to simulate the functional aspects of the Apple 1 so that all hardware

and software designed for the Apple 1 can be used. The plus is based on the limited edition tenth anniversary

edition shown below.

Figure 3: Key omponent features on the limited edition repli a 1 ten

Not just a simple hobby board. The replica 1 contains features such as Apple 1 compatible expansion slot, and a

USB connection for power and serial to USB connection. The USB to serial port allows you to run a terminal

program on your Mac or P and you can load and store programs to/from your P to the replica 1. The USB

mini connector gives a modern standard so there is no more hunting for power supplies. Most USB power

supplies with at least 500mA will work great. We even offer a power supply and cable if you can't find one.

Firmware upgradeable: The replica 1 ten includes a Parallax Propeller micro-controller for the onboard I/O. The

source code is open source and is included with the replica 1 on the D and updates can be made via free

software to program the Propeller from Parallax website. Programmers are welcome and encouraged to use the

Briel omputers forum to announce custom developed features and improvements to the firmware. The owner

takes all responsibility for any firmware installed that is not released or approved by Briel omputers. Using

untested firmware could damage the replica 1 plus, however with the Parallax software, restoring is easy.

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Replica 1 plus Users Manual

The original 40 pin header that was offered on the previous versions of the replica 1 is now gone. It still remains

on the 3 slot expansion board for those who want to do their own hardware experiments.

As well as being able to run all the original Apple 1 software and hardware, the replica 1 has the capability to

use modern hardware like a ps/2 keyboard and use a standard USB connector power supply. The added USB

serial port gives the user the ability to download programs right from your P or Mac into the replica 1 making

software sharing possible.

Figure 4: Logi diagram of repli a 1 plus omputer

Keeping a simple design structure was important with the replica 1. hip reduction is the way Woz designed the

Apple 1 and the replica 1 follows in its path. Only 8 I chips are now on the replica 1 plus the serial USB

adapter making it the most efficient replica 1 ever. The replica 1 ten continues uses the new Parallax Propeller

as the I/O controller plus it is now the master 1MHz clock and replaces 1 I for logic. This new micro-

controller has the ability to handle all I/O including video, serial, and PS/2 port.

While the replica 1 has been in production for over 10 years, it is always a work in progress. Sometimes bugs

and fixes come up and changes to the board are always discussed on the replica 1 forums. For the latest in

design changes and modifications, see the replica 1 forum at:

http://www.brielcomputers.com/phpBB2/

The replica 1 plus is currently the most advanced replica Apple 1 produced. It encompasses features as

requested by current or future owners of replica 1, as well as design improvements, bug fixes and other

enhancements. All revisions remain mostly backward compatible with the original replica 1.

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Replica 1 plus Users Manual

Chapter 3: Unpa king and Setting up system.

Before you begin setting up your replica 1 computer, make sure you have plenty of table space. Do not power

up the unit while touching any part of the circuit board and contact Briel computers if you are unsure about any

part of the setup process.

You will need the following items to get your replica 1 up and running:

1. The repli a 1 system board.

2. Mini USB onne tor to PC/Ma or power supply.

3. PS/2 PC style keyboard

4. A TV with omposite video in, or a omposite omputer monitor.

5. A video able to atta h to the TV from the repli a 1.

Place or mount the replica 1 board so that it is secured. Make sure no metal objects can touch the circuit board

or damage could result. Next you need to choose what type of power supply you are going to use. There are two

ways you can power your replica 1 plus. The mini USB cable is not only the serial port but also the power

source. If you intend on using the replica 1 ten just off your computer, you don't need a power supply. Try not

to use the replica 1 connected to a USB hub as the power requirements are different than a direct port.

Using a serial terminal program on your computer you can choose to use that as your keyboard and display if

you wish or connect a PS/2 or AS II keyboard and video monitor.

Figure 5: Mini USB onne tion for power and USB to serial port onne tion

Once you have the power source connected, you can attach your monitor or TV to the replica 1 with a standard

composite video cable. Most modern TV’s have a composite input located on the back of the TV. Plug your

R A style cable into the back of your TV or monitor and locate the video connector as shown and plug your

cable (not supplied) into the replica 1 (figure 6). The replica 1 ten was designed for NTS but the driver is

listed as being PAL ready. We can provide a PAL version on the D but can not test it at the moment.

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Replica 1 plus Users Manual

Figure 6: Video onne tor

Next you need to attach a keyboard. You have two choices for keyboards; PS/2 P style keyboard or an AS II

keyboard. To use the PS/2 style keyboard locate the PS/2 port on the back edge of the replica 1 and plug your

keyboard into that port (see figure 7).

Figure 7: PS/2 keyboard port

If you are using an Apple 2 or 2+ AS II keyboard, locate the AS II keyboard port near the replica 1 logo on

the board and plug your 16pin dip cable into the board. Note that pin 1 is next to the ‘A’ on the AS II

KEYBOARD label. Please note, you will need to supply your own -12V power for Apple II keyboards.

Figure 8: ASCII keyboard port

Now you are ready to test your replica 1 plus. Make sure your TV or monitor is turned on and flip the switch on

the replica 1 up. The red LED below the switch should light up and a screen of garbage should appear. If you do

not see the random garbage screen, or the LED is not lit, turn the replica 1 off and recheck your work.

Press RESET on the board and your replica will respond with a backslash “\” and the cursor will drop to the

next line. The cursor is a blinking ‘@’ symbol just like the original Apple 1 computer. You are now in the Woz

monitor and ready to use your replica 1 ten. If you are using the PS/2 style keyboard you will notice that the

caps lock is already on by default for you. The apple 1 only understands uppercase characters so does the

replica 1.

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Replica 1 plus Users Manual

Chapter 4: Assembling the repli a 1 plus kit

If you have experience with soldering circuit boards, then not only will you enjoy the replica 1 kit, but you will

also have the pride in assembling it yourself while saving money. If you have never built a circuit board kit,

please start with something a little simpler before attempting to build the replica 1. This chapter is only

designed as a brief guide to help you assemble your replica 1.

Kit ontents:

QUANTITY DESCRIPTION

1 6502 CPU

1 6821 PIA

1 27C128 EPROM

1 62256 SRAM

1 P8X32A-D40 PROPELLER

1 24LC256-I/P SERIAL EEPROM

1 74LS00

1 74LS138

1 5MHZ CRYSTAL

3 40 PIN MACHINED SOC ETS

2 28 PIN MACHINED SOC ETS

1 16 PIN MACHINED SOC ETS

1 16 PIN DUEL SWIPE SOC ET

1 14 PIN MACHINED SOC ETS

1 8 PIN M ACHINED SOC ET

2 RESET & CLEAR BUTTONS

2 100 OHM RESISTOR R21, R22

2 220 OHM RESISTORS R23,24

1 560 OHM RESISTOR R25

10 1 OHM RESISTORS R11-R20

9 3.3 OHM RESISTORS R1-R9

1 10 OHM RESISTOR R10

1 Q1 TRANSISTOR 2N4401

2 .01uF CAP C9 AND C10

8 .1uF CAPS C1-C8

1 10uF RADIAL CAP C11

1 RCA CONNECTOR YELLOW

1 44 PIN APPLE 1 SLOT

1 PS/2 EYBOARD DIN CONNECTOR

1 RED LED

1 ON/OFF SWITCH BUT DPDT

1 REPLICA 1 TEN LIM ITED EDITION PCB

2 9 PIN HEADER FT232 BREA OUT

2 FT232 BREA OUT BOARD USB

2 2 PIN HEADER

2 JUM PER SHUNTS

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Replica 1 plus Users Manual

Tools required for assembly:

Soldering iron, solder, wire cutters, needle nose pliers, and a multi-meter

Before you begin:

Make sure you have proper working space and that you heat your iron before beginning the assembly. This kit

is not for beginners and Briel omputers assumes that you have some prior experience with soldering circuit

boards. If you have never soldered circuit boards before or don’t feel you are ready, you should build other kits

of a smaller, less complex nature before building your replica 1.

Reading and identifying resistors:

In previous revisions of the replica 1 kits, all parts were labeled in an effort to make it easier on the kit builder.

Now, the manual is being expanded to help newcomers to kits learn to identify the parts and read their values.

Resistors have 4 colored bands on them that are used to identify the value. The first 3 are the value and the 4th

colored band is to identify the tolerance of the resistor. The 4th band is usually silver for 10% or gold for 5%

tolerance. Here is how to read the other three to get the value:

Figure 9: Resistor olor ode hart

Let’s assume the resistor you are trying to identify has the colors orange, and then another orange, then a red

band followed with a gold band. So, to read the resistor, find the gold or silver band, that identifies the 4th band.

Hold the resistor so the 4th band is on the right side and read the first color on the left.

The first color is orange which has a value of 3 according to the chart above. The second color is also orange

which also has a value of 3. The 3rd number indicates how many zeros follow the first two numbers. So, red is 2

zeros. This gives your resistor a value of 3, 3 and 2 0’s (00) or 3300=3.3K. This may take some practice but

look through all the resistors and identify them without a meter if you need practice.

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Replica 1 plus Users Manual

Reading and identifying apa itors:

It takes less time to read the values of the capacitors than to read the values of the resistors. The key is to

understand and read the numbers correctly.

Larger capacitors may have the values clearly printed on them. For example:

10uF = 10 Micro Farads

Smaller capacitors however, may only have 2 or 3 numbers on them. For example, the 22uF capacitors say

22J. .1uF capacitors have the value 104 on them. This is similar to the resistor codes where the first 2 numbers

are actual numbers and the 3rd number is the multiplier code. So 10 X 4 is 100,000 and the value is in pico

Farads (pF). onverting it to a proper numbering format gives us the value .1uF. To make things easier, here is

a list of the values on the capacitors used and the numbers printed on them.

Power LED:

Figure 10: LED pin internal diagram

Looking at the LED there are two connectors, the Anode is longer and has the smaller connector inside. The

cathode is the negative side. It has a shorter lead and a larger part inside the LED. The cathode is the negative

post. onnecting is simple on the replica 1. The LED silkscreen on the replica 1 has the positive + marked.

Simply put the longer anode connector into the positive side when installing.

Ready to Begin Assembly:

Now that you have inventoried all parts you are ready to begin assembly of your replica 1.

Step 1: Start with the resistors. Bend the leads on each side of the resistor 90 degrees near the edge of the

resistor. Insert the resistor into its proper location until it rests flush with the board. They are not polarized so

that can be installed either direction. While holding the resistor with one finger, bend the pins on the bottom

side away from each other so that the resistor will not fall out and will stay flush on the board. Flip the board

over and solder the resistor down to the board. ut the extra lead length off and throw away. Repeat for all

resistors carefully making sure each one goes in the proper location.

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Replica 1 plus Users Manual

Step 2: Place the 5MHz crystal into its location and while holding it flush with the board, turn the board over

and set it on your work bench. Verify that the crystal is still flush with the board and solder the 2 pins into

place.

Figure 11: 5MHz rystal

Step 3: Insert the power switch so that the black switch portion sticks out off away from the board. Hold the

switch and turn over the board and place it on your workbench. Next carefully solder each pin down making

sure not to allow any solder to flow across to another pin. heck with a volt meter that no pins are touching.

Remember that some pins will contact because the switch is on or off.

Figure 12: Power swit h

Step 4: Next is the sockets. I like to start with the largest sockets and work my way down. Insert the socket so

that the edge with the notch in it matches the board. If you get this wrong, it is ok, it is just a socket and does

not matter if it is installed backwards. I like to solder 1 corner pin and turn over the board and check to make

sure the socket is flush with the board. Once you check that, solder the remaining pins.

Figure 13: 40 pin so ket

Step 5: Install the RESET and LEAR buttons. You can fold the tabs to hold the buttons in place while you

turn the board over. Solder the pins in place and check your work. Sometimes they shift a little and need

adjusting.

Figure 14: RESET and CLEAR button

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Replica 1 plus Users Manual

Step 6: Install the transistor. The pins may need to be separated a little to make them fit into the holes. Make

sure the flat spot on the transistor matches the flat spot on the board. Turn the board over and solder down. ut

away the excess leads.

Figure 15: Transistor

Step 7: Installing the serial USB power interface. The small red USB board supplies power and serial to USB

communication with the replica 1 to a P or Mac for data transfer. To install this board onto the replica 1, you

need to first install two 9 pin headers onto the USB interfa e. Push the pins through the bottom of the USB

board and rest it on the table with the pins on the bottom of the board. You have to be careful not to solder all

the pins right away or the spacing may be incorrect. Solder 1 pin on each of the two 9 pin headers. Make sure

the taller pins are pointed up through the USB board because you don't need a long lead through the replica 1

board. After you solder 1 pin each row, place the board and pins into the replica 1 board and adjust the headers

so they fit into the replica 1. Now that you have the spacing correct, while it is sitting in the replica 1 ten, solder

the remaining pins on the USB board. Hold the USB board still mounted in the replica 1 and turn the replica 1

over. Solder 1 pin of one of the 9 pin headers so the USB board is attached and check that everything is flush

before finishing up the remaining pins.

Figure 16: USB board

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Replica 1 plus Users Manual

Step 8: Install 2 pin jumpers. Hold one jumper and install it near the EPROM. While holding the jumper, turn

over the replica 1 and place it on the work bench. Allow the work bench to hold the jumper while you solder

into position. You may need to adjust the replica 1 to make the jumper stand straight up before soldering.

Repeat this process for the jumper near the AS II keyboard connector.

Figure 17: Jumper

Step 9: Install the LED into its location. The + lead is the longer lead. Make sure the LED goes all the way

flush with the board. You may have to wiggle the LED a little to get it all the way flush. Hold the LED into

position and turn the replica 1 over. Solder the LED pins and cut the extra length off.

Figure 18: LED light

Step 10: Install the 8 .1uF capacitors into the locations 1- 8. These capacitors are identified by 104 on the

them. These are not polarized so they can go in either direction. They vary by manufacturer so you may need to

adjust the pins to fit them into the board. I usually bend the pins away from one another to hold the capacitor in

place, then turn the board over and solder the pins. ut the extra leads off.

Figure 19: .1uF apa itor

Step 11: Install the two .01uF capacitors like you did with the .1uF capacitors. ID is 103M on the caps. They

are not polarized so you can install them in either direction as well. ut the extra length off.

Figure 20: .01uF apa itor

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Replica 1 plus Users Manual

Step 12: Install the 10uF electrolytic capacitor. This capacitor is cylinder shaped and black. They are polarized

and the longer lead is the positive side. The negative side has an arrow pointing down to the lead to help out.

Place the capacitor so it is flush with the board. Bend the pins slightly away from one another to help hold the

position and turn the replica 1 over. Solder the 2 leads and cut the excess off.

Figure 21: 10uF ele trolyti apa itor

Step 13: Install the video connector so that the round metal connector points out away from the board. Hold the

connector and turn the board over and place on your workbench. Solder the two pins down and use enough

solder to fill the holes completely.

Figure 22: video onne tor

Step 14: Install the 44 pin slot connector into its position. Notice that the socket may have identification of the

pin number on top of the socket. Look for the Z or the A and match it up with the board identification marks.

Hold the slot into position flush with the board and turn the replica 1 over. Solder 1 pin down and check that the

slot is flush with the board. ontinue to solder the remaining pins until all 44 are soldered down.

Figure 23: 44 pin ard slot

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Replica 1 plus Users Manual

Step 15: Install the PS/2 keyboard connector. Use caution as the pins are fragile and the fit is very tight. The

supplier recently changed brands and the connection is a little different. We have gone to great lengths to get the

PS/2 holes corrected and matched up just right. Take your time and the connector will fit snug. Turn the replica

1 over and verify all pins have gone through the board. Solder the pins onto the replica 1.

Figure 24: PS/2 keyboard onne tor

Inspe tion of your work:

Now that you have completed your soldering, take a few minutes and look over your work. heck for solder

spots that might not be good connections to the posts. Look for bridges where solder may have jumped over

where it wasn’t supposed to go.

Testing your repli a 1:

Before installing your I ’s, power up your replica 1. With your multi-meter, check the voltages 5V and GND.

make sure your LED is lit properly. Test 3.3V and ground. Test pin 14 and pin 7 on the 74LS00 to make sure

you are getting 5V. heck pin 8 and 16 on 74LS138 for 5V. Once you are satisfied that the power is being

distributed correctly, power off the replica. Install the P8X32A-D40 and 24L 256 EEPROM. Attach an R A

cable to the replica 1 video port and attach it to your monitor or TV. Power up your replica 1 and see if you get

a screen full of garbage. If the video section is working properly, turn off the replica 1 and install the rest of the

chips. Power up the replica 1 again, this time press ‘RESET’ button after a couple of seconds and see if the

replica 1 resets.

If the circuit is working properly, you will get a “\” backslash followed by the cursor ‘@’ moving to the next

line. At this point you can power off the replica 1 once more and attach your keyboard. Power up the replica 1,

reset the circuit and try out the keyboard. ongratulations, your replica 1 is now assembled and ready to use.

aution: Before plugging in the power supply, keyboard and video connector, thoroughly check

over your work for errors.

Any parts that get accidentally damaged during the building process can be replaced at the owner’s expense.

ontact Briel omputers for any replacement parts needed.

The goal of Briel omputers is that ALL replica 1 kits get completed successfully. If you are having a problem,

please feel free to ask for help.

19

Replica 1 plus Users Manual

Chapter 5: Programming the repli a 1

The replica 1 can be programmed in one of 3 built in ways. You can enter values into memory directly using the

Woz monitor. Another way is to use BASI that is built into ROM. BASI was the most commonly used

language among beginner all the way to experienced programmers in the 70’s and 80’s. The third built in

Using the Woz monitor:

The Woz monitor is a tool that gives you direct access to memory to program code that the 6502 will interpret.

manually reset the circuit to get the computer started. Simply press the reset button on the circuit board and you

will see a backslash ‘\’ and the cursor will drop below the backslash. You are now in the Woz monitor.

There are three basic functions to the Woz monitor. First, you can examine a range of memory or just one

location. To examine one location of memory, just type in the address and press [return]. To view memory

location 300 it would look like this:

300[RETURN]

0300: E1

The cursor will then move below the line that displayed the value of the memory location. To display a block of

memory, type in the starting location followed by a period ‘.’; follow that with the ending location. To view

300-32F locations, type:

300.32F[RETURN]

The replica will display the memory contents up to 8 locations per line:

0300: E1 20 94 17 08 26 60 10

0308: E4 98 02 86 88 44 A5 50

0310: 3C 2D 20 9D 7E 18 60 8C

0318: 0F 00 18 24 90 24 06 50

0320: 42 07 06 A0 89 81 00 C6

0328: 80 60 41 12 E0 1B A3 04

Again, the cursor will be below the listing.

To program a location in memory, simply type in the address followed by the value to write to it. For example,

to program location 300 with the value FF, simply type:

300:FF [RETURN]

The Woz monitor will respond by displaying the old value of the memory location:

0300:E1

20

Briel Computers Replica 1 Plus User manual

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