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 Post subject: Introduce yourself
PostPosted: Sun Sep 25, 2011 5:53 am 
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Joined: Fri Aug 30, 2002 1:09 am
Posts: 3787
Location: Southern California
Ed thought we should have an "Introduce yourself" topic to tell of your 6502-related history & interests. I'll start it off. There's no guideline for length of biography yet, so I guess I can do whatever I want. :lol: Please everyone, let's try to keep this as introduction only. For example, if you want to discuss a project someone mentions, please start another topic for it, instead of cluttering this one with things that are not strictly introductions.

My early interest in electronics (1970's) was in stereo and amateur radio, not computers. Remember the line in the movie "Pirates of Silicon Valley" where the executive, puzzled and tapping his pencil on the desk, said slowly, "What would the common man want with a computer?" (They must have had some good laughs making the movie.) Back then, computers were rare, huge, and expensive, and people who worked with them seemed next to God or something.

I've been inactive in amateur radio since 1984, maintaining my license only in case I'd want to make my own radar or missile-guidance system to take out an ice-cream truck or something exciting. :lol:

My computer interest began mildly when I wanted to do audio and RF circuit calculations that took thousands of iterations. I got myself a TI-58c programmable calculator in Dec '81. The next year, my schooling took me through a 6502 class with the AIM 65 computer, and a Fortran IV class which required doing our practice on the school's IBM 360 mainframe computer. You'd transfer your hand-written program onto cards at a big card-punch machine so the dresser-sized card reader could accept it, then rubber-band the cards together with a paper having your account number and put it in a cubby, and come back two hours later for a printout of all the reasons it wouldn't run. :lol: By then, the boys who could justify the cost of (or had access to) an Apple or TRS-80 or similar were using BASIC, and assembly if they were more adventurous; but the school was behind the times, I suppose. It reminds me of the 1969 movie "The Computer Wore Tennis Shoes" where the college was given its first computer, free, because it was already so outdated.

I worked as a repair tech at TEAC in Southern California in '82-83. There were about 120 employees, and only one computer in the building, occupying its own special holy room, off limits to all but two or three people, and all the sales and accounting people had terminals hooked into it. It was only for data processing, not at all for embedded control which would soon become my greatest interest. By then some of the tape recorders I worked on there had microcontrollers (with bugs), although microcontrollers were definitely not ubiquitous yet.

A friend had an HP-41 calculator but I didn't initially think I could justify the expense. When I worked in applications engineering in '84-85 at a VHF/UHF power transistor manufacturer, having an ultra-portable hand-held unit to control repetitive processes with the lab equipment became quite attractive, and the HP-41 calculator fit the bill. It could be taken from your desk to your workbench and back, much more easily than laptops (which didn't really exist yet). In 1986 I was the only engineer working at a much smaller company and, having gotten an HP-41 by then, I set up our first automated testing of products with it. The I/O programming on it was much easier than doing it on a PC. People would nearly wet their pants when they saw a hand-held unit controlling a stack of lab test equipment. :lol:

There was a ton of wonderful IEEE-488 test equipment to drool over in the thick, hard-bound Hewlett-Packard catalog that came out every year. I couldn't afford it, but it didn't take a genius to see the possibilities with making my own computer and rigging up inexpensive substitutes with A/D and D/A converter ICs, relay outputs, etc.. Soon I wanted microsecond control of the pins, something I couldn't get with the HP-41 or 71 (even programming them in assembly), and I was dreaming of something like my workbench computer you can see in my project pages. Although my first one (1985) worked, it was far bigger and more complex than it needed to be, and wasn't much good for anything. I did learn a lot about what would be good though.

In 1986, my employer came to me with an idea for a timer to put in an earcup of an aircraft headset to beep you when it was time to switch fuel tanks, arrive at a waypoint, etc.. No one had such a product. His idea of how to work it was totally impractical though, and I thought, "If we used a 6502, the capabilities could be vastly expanded without adding much hardware complexity." I was very green at making computers, and at how a project like this ought to be managed, but the boss didn't know any better either, so he set me to work on it. Now it was to go in the intercom (instead of a headset) and to display checklists, hold flight plans, etc.. He frequenty came to me asking, "Can we do such-and-such too?" and I'd immediately envision how, and tell him yes. "Feature creap" set in like crazy. Every few days he came to me with a new wish list for Santa Claus, and I obliged. For awhile it even had a very compact cassette drive that the computer could control, and we put data on one track and voice on the other. I designed a tape modem we could make for under a dollar. Someone else was in charge of packaging and mostly killed the product before it was solidly launched, because they made it too labor-intensive to assemble. I learned a ton though.

Of a later set of automated test equipment I set up there, there were initially supposed to be seven sets, so "rack-and-stack" IEEE-488 equipment would then be too expensive, especially if a deal turned sour and one of our Korean suppliers kept our hardware (which did happen later). So since the programming and design time could be amortized over plenty of sets if we made our own, that's what we did. STD bus (which stands for "simple to design," not "standard") was chosen for its low cost and wide range of available boards, and I designed several more custom boards. The computer board used a 6502, and I programmed it in Forth.

I had a couple of false starts on making a nicely packaged workbench computer with an ABS plastic box that could be thrown in the attaché case, then in just one week in 1992, built the original form of the 6502 workbench computer I use now. Every few years I added something to it (such that the pictures at the link are very outdated now). It has proved incredibly valuable for controlling experiments and processes on the workbench, trying new ICs we would put in products, and programming PIC microcontrollers for several products. It actually has a 65802 now, not 65c02, and I developed my bank-0-only '816 Forth on it.

I have some articles on this website and my own:

I started some others years ago and was delinquent about finishing them (hopefully I can still get to them in the future):
  • Primer on synchronous serial: dumb shift registers, I²C, SPI, Microwire, 1-Wire, SMBus (I do have a brief comparison of them though, here)
  • primer on multiple-precision, scaled-integer, and fixed-point math in place of floating point which incurs a much heavier runtime overhead and is totally unnecessary for most applications, even scientific! (I later summarized much of the planned material in the explanations on the front page of the section of my website on large look-up tables though.)
  • publish my '02 and '816 Forths

I would like someone else to write 65-related articles on:
  • file systems, kernels, and OSs
  • multitasking, coöperative and preëmptive (coöperative is very easy on the 6502 in Forth), multithreading
  • multiprocessing
  • DMA
  • video
  • MMUs
  • using DRAM
  • memory banking on the 6502 and how to program for it, looking through a window in the main memory map

http://WilsonMinesCo.com/ lots of 6502 resources

Last edited by GARTHWILSON on Thu Apr 05, 2012 7:25 am, edited 6 times in total.

 Post subject:
PostPosted: Sun Sep 25, 2011 6:27 am 
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Joined: Thu Dec 11, 2008 1:28 pm
Posts: 3251
Location: England
A sticky topic! Thanks Garth!

I thought it would be good, both for newcomers to the board to get a feel for the regulars here, and also to help with the getting-to-know-you stage: because we all have different interests and different depths of experience. For some, 6502 is all about soldering and for others it's all about assembly language programming.

Also, some of us have been interested for decades and it would be nice to hear about people who are new to the 6502, and why!

About me: Someone gave me a "How Why and Wonder" book of computers at an early age, and someone mentioned electronic brains, and that must have set me off. There was a diagram in that book with a battery and a light bulb and two switches in series, which was supposed to illustrate AND logic. I didn't get it, but that was a challenge.

Maybe this was the book?

At the age of 13, I got a paper round, and sometime around then I started buying "Practical Electronics." There was a hugely complex project to build a Mastermind game with 74-series logic, and shortly afterwards a much shorter project to do the same with a micro. I'd done a paper design to make a combination lock with 74-series, which had got out of hand, and it was obvious that microprocessors were the thing.

The AIM-65 was advertised around that time, maybe the KIM. Certainly the MK14 (an SC/MP thing, cheap but not very capable) was.

So when the magazine had a series on the Compukit UK101 (August 79), that had to become my first microcomputer - expensive as it was, and I think I needed a matching grant from my mother (which was unheard of, don't tell my brothers.)

But wait! In fact earlier than that, me and a couple of friends had put money together to hire a PET. That was mad. It might have cost £65, we had it for 24 hours, stayed up all night, achieved very little. Bear in mind my weekly income was probably no more than £2.

So maybe the 6502 had already loomed large before I'd gone for the UK101.

(The UK101 was a kit, so it was also my first real effort at soldering: I had a grab bag of 74-series which I'd bought for the combination lock, and might have had some vero board, but I don't think I had any experience. The 101 didn't work first time, so I just re-visited every IC pin, and it worked second time. I had no test equipment, unless there happened to be a multimeter around the house, so I don't know what I would have done if it hadn't.)

Some years later I bought a Beeb - I know they were only for rich kids, but I had a secret. I was a student, and in those days if you spent no money at all on living (i.e. drinking, smoking, other forms of intoxication) you could actually run a surplus.

Some many years after the Beeb, I went for the Amiga, but then we're straying off topic. By then I'd started work in the chip industry, and for the most part I've worked in or near CPU teams, in supporting roles. It can't be entirely coincidence: I continue to find processors fascinating.

Most recently, I've picked up on FPGAs and got involved with the visual6502 project. Having the 6502 circuit and layout to analyse and simulate is great. Being able to make our own chips is also great - updating a chip design in-circuit in a matter of seconds is extraordinary.

Long story short: I end up fixated on computers, on logic, on electronics, on the 6502 in particular. I find small programming puzzles interesting, and large programming projects difficult.

My aim here is to keep up the good work: keep turning up interesting facts, old histories, helping with problems or research, answering questions. Most important is with welcoming newcomers to the forum, and new people to the 6502, because we're all getting older.


 Post subject:
PostPosted: Sun Sep 25, 2011 10:01 am 

Joined: Tue Jul 05, 2005 7:08 pm
Posts: 558
Location: near Heidelberg, Germany
I happened to get access to a "real" computer when I was at school, must have been around 1982 +/- a year or so. That was when I got into our school's "Computer AG" (computer work group). The computer was an HP I don't remember the model, it had a simple BASIC built in, a cassette port, a screen you could write to but no full-screen editor. IIRC it even had punch card reader I never used. I wrote a few programs for it in fact.

But shortly after that the Computer AG got a - then already old - 3032 with a 3040 disk drive. What a revelation! A comfortable full screen editor, you could even get into machine language with it, and a fast disk drive with random access (at least compared to the tape...). I did write a number of programs there, learning asI went, still my code looked more spaghetti in those days. The AG then got a 4032 and an 8032 with 8250 disk drive and printers, I even got a key to the "computer room" as a regular :-)

A friend of mine got a VIC20, we were playing games with it, but he had a tape only at first, so it was very tedious. I got me some jobs during school vacations to buy me my own C64 - with disk drive of course. I was disappointed by the speed of it compared to the PET's drives though. For the C64 I also did a lot of programming. My programming style slowly got better :-)

Together with a friend I was building a telephone switching system during my last years at school. He was doing the hardware and I was doing the software, all based on 6502. It used pulse dialing so a 6502 could easily count the numbers, and we were aiming for conference calls, call redirection and what not. It actually went through several complete hardware and software remakes, and never really saw the light of day,
but I learned a real lot about structuring programs and maintainability. I even claim that this is my first object-oriented program, as the final version had data structures for each hardware (like phones and switch lines), and sending "messages" was done by setting flag bits in that structure that the handler would evaluate asynchronously ;-)

When I got to university I already had an Atari ST to play with. I never left the 6502 though. I was trying to port one of my favorite 3032 games (break out) to the C64 - and miserably failed. That was the first timeI really got the feeling for what would happen when the old computers were completely gone and all the software and data for them being lost. That's why I started my own CS/A65 computer project, and that is also the reason why at a later time I worked on the VICE emulator - and in fact added its complete PET and CBM-II emulation.

My CS/A computer is now documented on the web http://www.6502.org/users/andre/csa/index.html One thing that kept me going over all that time was that there were so many new features in the new PCs like MMUs, write-protected memory, no-execute bits, blitters, memory faults exception handling, but also SCSI, SD-cards, Ethernet or even USB where I thought that this should be possible as well with a 6502. I took this as a kind of challenge and in fact I have done all this with my CS/A.

However, now after over 20 years it is finally reaching the end of its timeline. In the beginning I decided not to use programmable logic to make it easy for anyone to re-build this computer. But I found that some of the features I did were only easily doable with programmable logic - so I rebuilt a more reliable version of my SIMM ramdisk or built my blitter using CPLDs. Even more it seems that 5V logic is on the decline and 3.3V or even 2.5V logic is getting more and more important. Processor bus speeds are increasing but they are not routed over a backplane like with my CS/A anymore - here I/O busses are used more and more. Also there of course is the final challenge - make the 6502 more than 8 bit...

And that is what I am working on now, the 65k project http://www.6502.org/users/andre/65k/index.html . It puts the 6502 into an FPGA programmable chip, but I am not using one of the "known" 6502 cores, but I am extending the design to up to 64bit register width. It is still in the design phase, it will be binary-compatible (but not timing-compatible) with the 65C02, and still be able to "big stuff". This is a big difference to the 65org32 extended 6502 where a "byte" is not 8 but 16 or more bits (so it is not binary compatible anymore). I plan to do some hardware for it, but nothing's finalized yet.

If you have a feeling that sometimes my 8bit activity goes like on-off-on-off you're right. I have a job, a real life and other obligations so that I have to make do with the time I have left. But I'll never forget the 6502 :-)


 Post subject:
PostPosted: Sun Sep 25, 2011 12:35 pm 
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Joined: Tue Mar 02, 2004 8:55 am
Posts: 439
Location: Berkshire, UK
My interest in computers started at secondary school in the mid 70's when I discovered a room containing an ICL 4/30 mainframe that had been given to us. As no training had been given to anyone when the machine was donated we couldn't use the official operating system so we got out the instruction reference manuals and started from there. Initially we didn't even have an assembler. We wrote code in hex on paper and punched it onto paper tape for loading. Even today I can still remember the hex values of the main opcodes.

When the Commodore PET came out the school bought one for our main computer science teacher. I used to stay after school to write bits of BASIC on it. A UK magazine (Electronics Today I think) published an article on the 6502 and inspired me to start using machine code in some of my PET programs to speed things up. Again I wrote the code on paper and used a petmon program to enter it into the computer - An approach that works well as long as you leave a few NOP gaps every so often for when you miscalulate the size of an instruction and have to fix up all the following addresses. I co-wrote a few games for the PET that we advertised and sold mail order.

I had a play with electronics at school but never had the pocket money to pull together all the tools and components for my own computer. I nearly got a Sinclair ZX-81 but after seeing a mate's one I decided not to.

When I went to college in 1981 my usually tight fisted father dipped into his pocket and bought me a BBC Model B. A friend got me some part time work with a management consulting firm (SRI International) writing some APL programs on a CP/M system that paid for a hard disk upgrade and a double sided 100K drive for my beeb. I wrote a couple of BASIC games for the BBC at the request of a friend. Only a couple of years later did I discover that he had passed them off as his own and sold them.

The BBC went with me University where I studied Software Engineering with someone that had taken a year out to work for the Microelectronics in Education Programme, a government funded group that wrote educational software for UK schools. We ended up writing a database package in 6502 for the BBC and a few other things together that helped pay off my student debts and kept me in beer money. Through the university I ended up working during the holidays in the R&D department of a local software company, often on BBC related projects like transmitting static text and live ViewData pages over the ring mains to other BBCs in the building (a bit like a simple in-house Internet).

My BBC was slowly expanded with 65C02 and Z80 second processors. Acorn lent me a 32016 second processor at one point but it was terrible to use. They also gave me a 20Mb hard drive.

I kept my BBC until 1991 when it was sold to a local school and I got my first PC. I wish now that I had kept it and am very tempted to buy one off eBay. I found an excellent emulator in the late 90's and used to take a BBC Advanced User Guide with me on business trips so I could write code in my hotel room.

I started tinkering with electronics again the around 2002. My wife sent me to Maplin to buy bits to make some audio cables to connect microphones to a mini-disk recorder. I came home with a copy of thier catalog and was intrigued by the PIC Microcontrollers. I now have lots of components but very little time to do anything with them - I spend too long commuting each day to have the energy in the evenings for serious projects. I have an XESS Xilinx FPGA card and spent sometime learning VHDL but haven't done much with it.

My passion is for programming rather than hardware. I grew up with the 6502 and had a lot of fun programming it. One day I'll finish my R6501 project but my dsPIC based emulator will probably be completed first.

Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.demon.co.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.demon.co.uk/dev65/
PIC Based 65C02 Emulation - http://sourceforge.net/p/em-65c02/wiki/Home/

 Post subject:
PostPosted: Mon Sep 26, 2011 1:34 am 
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Joined: Mon Mar 02, 2009 7:27 pm
Posts: 2916
Location: NC, USA
BigEd wrote:
A sticky topic! Thanks Garth!
Second thumbs up for a sticky!

My brother and I first came into contact with a 6502 single board computer when our dad brought home either a SYM-1 or AIM. I forget. I do remember playing a bowling game I loved. It was black and white, the bowling ball would scroll up and down on the left side of the screen, and when you thought you could get as many pins down you would hit the enter key. It was pure magic. A most excellent form of entertainment. I believe I was 11 or 11 yrs old at the time, in the 6th grade elementary school. My brother was 2 years younger. Before that we used to play cards or chess...

Our second contact with a single board computer (although 8048) was the Magnavox Odyssey 2. Awesome graphics, compared to the previous machine. Munchman, LOL. Even before Pac-Man...

Our third contact with single board computers was on a most excellent Christmas. One I will never forget!. It was a few years later I think, dates are blurry as this was almost 30 years ago. But I got an Atari 800 and a 13" color TV, and my brother got an Atari 400 with a 13" color TV, and we loved those games! Asteroids, Pac-Man... Then we started seeing arcades! It was a revolution! Much better graphics and sound in the arcades...
I got my feet wet programming Basic. I remember simple SIN/COS graphic routines in color, and I would experiment changing the formulas and watching the patterns... Magic to such a young mind, and the realization of the discipline of mathematics.

Then my Dad got a Commodore-64, but that was in my parents' room. Forbidden territory, right? But he would let us play some games in there, I remember Jumpman. My Dad, being an EE, had a digital scope hooked up to it. Amazing what kids will remember, eh?

So next year for Christmas, I asked for a C-64 and got one! I believe I was a sophomore in high school, around 16 yrs old. Already interested in electronics with a good friend of mine we both collaborated and shared knowledge for both of our science fair projects. Actually he shared a little more as he was more learned in digital electronics. This guy had knowledge of digital timing delays in TTL logic and was doing timing diag's at 18 yrs old! Needless to say his project was a 1024x768 color video board hooked up to the C-64, very impressive. He placed first. I had pursued 8-bit digital audio sampling and got third... At this point I was already heavy into the 6502 machine language and was displaying 320x200 "hi-res" audio waveforms on the C-64. From this project I went on to develop my own 6502 system, although it was still tethered to the C-64 expansion port. It eventually became a audio programmable wave generator. The wave was a repeating 256x8-bit pattern outputted through a DAC, although I never did get the analog portion 100%. It was preprogrammed with sin, square, triangle, and sawtooth waveforms. One could also input a custom waveform with switches in the front panel.

Then I went to college, Drexel University for Computer Engineering. I was an absolute failure. The course load was tremendous and I was not prepared for the partying either. I dropped out when I was 22 with a 1.6? GPA. Such a sad waste of money for my parents. What a disgrace I was. I abandoned electronics and pursued another interest that I had in cars. Modifying them to make them faster, namely my 1986 Camaro. I decided to pursue a hands on career in the automotive industry. I graduated a community college with 2 yr. Associates Degree with a 3.8 GPA and started internship at a local dealership...

Then after almost 20 yrs of not working with low level digital electronics (although, I had been building fast PC's, 1 water cooled), I woke up one morning and said to myself I want to build a 6502 based system to measure pulse widths of fuel injectors (although that project is on the backburner ATM). I did some searches for 6502 forums and found this one and made my first post here in March 2009. From there I went on to see about some amazing new technology had arisen since my slumber, and I pursued it. Namely FPGA design, and 6502 softcores that can go much faster than presently manufactured 6502 IC's. There were many threads already here on this forum about putting a 6502 in an FPGA which got me wanting to learn this new technology in the worst way.

I currently pursue a development board for a 16-bit 6502 with the help of some fine folks here on this forum.

 Post subject:
PostPosted: Mon Sep 26, 2011 5:08 am 
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Joined: Fri Aug 30, 2002 9:02 pm
Posts: 1195
Location: Sacramento, CA
My first computer was a kit called the Netronics ELF II. I was 14 years old when I bought that kit. It had an RCA CDP1802 processor, 256 bytes of RAM, 256 bytes of PROM, and a two-digit hexadecimal display and keypad. After soldering the main board and the expansion board, I powered it up and the display came alive! You had to key in the machine language by hand and then run it. I cut my teeth on machine language with this computer. I later built a memory expansion, cassette tape storage device, and even an SP0256-AL2 Speech generator that I bought at Radio shack. It used phonemes to create words. It’s first words were “Want to play a game?” I still have it buried around here somewhere.

My sophomore year, we got an Apple ][ computer at school and I learned to program it in BASIC and assembly. I spend many hours after school playing with it as my teacher trusted me to lock up after I left.

I later bought a Commodore 64. I found it easy to program and fun to experiment on. I wrote several utility programs in assembly on the Commodore, including a touch tone dialer and a game I called Mortar Fire, which was basically two cannons facing each other. Each player took turns entering in the angle (accounting for wind and different heights). I also ported the SP0256-AL2 to the C-64 and let it output speech. I later found a neat utility that did the same thing using the SID.

After trolling in college for a year I joined the Air Force and learned to maintain Telephone Central office switching equipment. It was all electro-mechanical then. Later we upgraded to digital switching and I learned to program switching systems.

Somewhere along the way I purchase a Laser 128 (Apple 2c clone). I dug out my assembly code from the C-64 and started writing new programs for the Apple. I used the EDASM assembler and wrote several programs – experimenting in 2D and 3D generation. I was making simple “worlds” similar to the Battlezone display. The Laser 128 died a few years later at about the time PC’s were becoming popular and less expensive.

Having moved up to the PC, I soon discovered that trying to learn PC assembly language was too much work.

That’s when I decided I wanted to build my own computer. Starting small, I took examples from others here on 6502.org. That is when SBC-1 was created. I followed that up with SBC-2. I offered two bulk orders (not for profit – prices covered costs only) for those boards and sold more than 25. It was a great starter platform.

I went on to create a 65816-based board that included a CPLD to generate color video and another CPLD to provide an SPI interface. This was SBC-3. I sold approximately 18 of those in another bulk order. I added an IDE/Compact Flash storage system that supports FAT-16 and wrote a new OS to support that. I later added an Ethernet interface and built a small webserver. That required me to create platform-specific drivers for the CC65 C compiler. Someday, I would like to optimize CC65 for the 65816.

My last creation was SBC-4P. It is modular in design and also has a 65816. It allows each builder the opportunity to tailor the IO to his or her own needs. It can support up to 4.5MB of SRAM (thanks to Garth's 4MB memory module), a serial terminal running at 115200 baud, and up to 4 IO modules with 32 bytes of IO and dedicated IRQ each. I have designed a terminal board with text video and PC keyboard input, a generic IO with 6522 VIA and 65SPI SPI master interface. Users can also design their own IO.

I’m not sure where I will go in the future – making some “standard” IO modules for 6502-based systems is one possibility. I’m finding time to be my biggest roadblock.


Last edited by 8BIT on Tue Oct 11, 2011 4:33 am, edited 2 times in total.

 Post subject:
PostPosted: Mon Sep 26, 2011 2:39 pm 

Joined: Fri Jun 27, 2003 8:12 am
Posts: 618
Location: Meadowbrook
I had been in electronics since a young age, tearing into stuff while in the single digits. Was doing electronic stereo repairs through middle school. First planned computer would have been 8080 based card system, never built. did actually start on a TI then my main axe was a handmade Apple ][. as in solder all the parts to a blank board. A kewl friend helped teach me 6502 programming. She later became one of the 3 founders of a company called Interplay.

My first 2 main jobs were with arcade game manufacturers where I was going wild using the 6502 wherever I could. I had many favorite projects but the biggest was for a game system called Neo Geo where I used an Apple 2E inside intercepting data and address lines to read scoring and dispense tickets, turning a regular videogame into a ticket game. Due to the different memory mapping on each Neo Geo game, it quickly got out of control to make this compatible with all the games available, so the project was never released.

A fun project which got me a developer of the month from WDC was an automated test fixture for DVD/LCD players for automobiles. It would run solonoids to press buttons, visual cues by using test DVD color patterns and sound tones. This project used the 65C134 due to the ports needed.

My biggest project to date has been going for years being a pinball computer. The Bally home pinballs have an unrepairable CPU so the call was needed. This is still a major work in progress.

"My biggest dream in life? Building black plywood Habitrails"

 Post subject:
PostPosted: Mon Sep 26, 2011 7:11 pm 

Joined: Tue Sep 24, 2002 4:56 pm
Posts: 50
Location: Essex, UK
Hmm... I'm not sure my background is quite as "rich" as those that have already posted, nor do I have much electronics experience, but here goes...

I think I'm a few - but only a few! - years younger than the like of Garth and Ed: my first experience of computing was back in the early 80's - my father bought a ZX81 sometime around '82-'83, and I received a ZX Spectrum for my birthday in '83 (I believe - it was one of the later rubber-keyed machines, so wouldn't have been earlier, or later, than this).

I still have my Spectrum (and it still works, more-or-less :D ), but my interest was really piqued by the BBC micro - whereas the Spectrum remained (for me) a computer to play games on, the Beeb was much easier to program, and this is what I tended to do, though rarely venturing further than odd utilities.

More recently - and with the "help" of eBay :wink: and computer shows and fairs - I've managed to acquire many of the peripherals I never had when young(er), such as "second processor" units, and also a range of early 80's computers, many of which are 6502-based. (Why? Personal interest, and vague "I could do 'X' with this" ideas, occasionally dressed up as preservation :D .)

Anyhow, I "came across" this forum a few years ago, and visit (ir)regularly, tending to lurk and browse, seeing what others are up to, and (very occasionally) even offering my own £0.02's-worth to the threads...



Martin Penny

.sig in beta - full release to follow.

 Post subject:
PostPosted: Tue Sep 27, 2011 2:38 am 
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Joined: Mon Aug 08, 2011 2:48 pm
Posts: 793
Location: Croatia

I am Dajgoro(not a Croatian name), from Croatia, actually i started sending pm to BigEd about opening this topic, i am glad that it worked out well.
I am not quite old as most of you here present, i was born in 1992, and since i can remember i was kinda interested in electronic. While i was still a kid i remember blowing up accidentally a lot of stuff around the house(short circuits, ect...). My first computer was kinda of a old ms-dos computer(don't remember which one), and i remember frying tv sets while playing Nitendo games... Later i first started playing with relay circuits, transistors, it took me a while to find out how to wire up a cmos chip(since then i built many electronic devices), also i made lot of stuff with QBasic...
After that i started doing stuff with pic microcontrollers, and after a while in high school i finally met the 6502, our teacher chose it as a simple to explain cpu, so we had class and exams about the 6502.
After high school i went to study at the University of Zagreb, Faculty of Electrical Engineering and Computing. In the first semester i had some bad luck with my jdm programmer, so i had to get one new. While waiting for a new one(from ebay), i started doing stuff with vacuum tubes, i made myself an amplifier(from old radio parts) and a vu meter. Still i am planning to make some other devices with vacuum tubes... After a while i got a nice Chinese universal programmer, which could program all kind of stuff, so i remembered(actually when i saw that i now could program eeproms i started thinking...) about the 6502 and the Z80(form the shop catalog). First i decided to go with the 6802(it was cheaper on ebay), but then i decided to go for the 6502.
In the second semester i stumbled across Daryl's Computer Hobby Page, and there i saw the SBC-2, i knew i had to make something like that, so i started asking questions, and Daryl told me about this forum, and since then i am here...
I am still building my SBC, it looks promising.
Now i have 3x 6502, and i am thinking about other 6502 projects...

Thanks a lot to BigEd(for answering all my pm), 8BIT(for answering all my emails) and all of you for your help!

 Post subject:
PostPosted: Wed Sep 28, 2011 9:07 pm 

Joined: Wed Sep 28, 2011 6:01 pm
Posts: 2
Location: Pennsylvania
I've been playing around with computers and electronics since 1976 when I went in the NAVY. The first computer I worked on was the AN-UYK20. I taught myself machine language programming via the front panel since I didn't have an assembler, which was hard on my thumbs. Google the AN-UYK20 and take a look at the pics of the inside panel and you'll see what I mean.

The first real commercial computer I had was a Commodore 64, which I still have, although slightly modified (aluminum case w/fan and a keyboard on a three foot cable) along with two 1541 floppy drives. I learned 6502 programming on the C64 and will see if I can resurrect my old system tonight for use as a development platform.

I've always loved programming the 65xx processor and I'm looking to get back into electronics and systems development. I still have some old Rockwell 65Cxx chips laying around and I think it's time to put them to use.

I have a couple projects in mind but first I'm going to take a stab at building an SBC of my own design if I can just find my old wire wrapping gun...


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PostPosted: Wed Sep 28, 2011 10:04 pm 
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Joined: Thu Dec 11, 2008 1:28 pm
Posts: 3251
Location: England
Welcome! That Navy/Univac computer is quite a machine - 16 bit words, which reminds me of our 65Org16 project. Good to hear about your adventure with machine code - I bet a few of us have done a bit of hand-assembly, but not so many have worked a front panel. I've done the first, but not the second.


 Post subject:
PostPosted: Thu Oct 13, 2011 7:07 am 

Joined: Sun Sep 15, 2002 10:42 pm
Posts: 214
I started out on an Apple //e and learned BASIC and assembly language in my teen years.
Took a year of college, was bored, dropped out, got a job in the games industry.
Bopped around in the games industry and wrote bits and pieces of many titles:

6502 assembly for Ultima V (Apple //e) at Origin Systems, Inc
6502 assembly for Skate or Die (Nintendo 8-bit) at Electronic Arts
6502 assembly for Indiana Jones and the Temple of Doom (Nintendo 8-bit) at Taito R&D
C code for a custom paint tool (NuPaint) for console game machines at LucasArts
6502 assembly for Defenders of Dynatron City (Nintendo 8-bit) at LucasArts
65816 assembly for Zombies ate my Neighbors (SNES) at LucasArts\

After that I went to Sega and wrote a 3D graphics engine for Roach Rally (PC, unreleased)
and maintained the Sega release of GCC for seven years. After Sega divested themselves
of hardware, I went was hired by Hitachi Semiconductor (which became Renesas) to work on
a Javacard port and also manage GCC worldwide development for the SH-series and H8/300 series

After that I did some consulting and wrote a valgrind-clone (basically a MIPS JIT) for
Sony Computer Entertainment, wrote two custom programming languages for Narus, and worked
on the Webkit Squirrelfish Javascript JIT for 2wire, and I'm currently at Ubicom working on
functional and cycle-accurate processor pipeline models for both current and next-gen
processor architectures and providing compiler-centric input on the next-gen instruction set.

I've done assembly language programming on 6502, 65816, Z80 (briefly), 68000, SH2, SH4,
H8/300H, MIPS, x86 16-bit, x86 32-bit, x86 64-bit, and Ubicom32.

I've left some stuff out - if you want to see the full list view my linkedin profile:


I'm the original author of Qforth which is maintained by David Wheeler:


Ronald T Kneusel ported Qforth to the Mac using a 65C02 interpreter. I can't find the current webpage for it, but it's mentioned at:

ftp://eris.giga.or.at/pub/c64/library/c ... #Emulators

Also the author of FASM:


I've contributed code to the Linux project for the sun3 and Rensas SH4 targets, so
my name is in a few places in the kernel, and I contributed patches to GCC for the
SH target between 1993 and 2004, so my name is in quite a few GCC changelogs.

PostPosted: Thu Oct 13, 2011 10:58 pm 
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Joined: Thu May 28, 2009 9:46 pm
Posts: 2707
Location: Rural Will County, Illinois USA
I suspect I am one of the older—possibly the oldest—denizens here. When I started with electronics the transistor was barely out of the laboratory stage of its existence. Electron tubes in the radio and monochrome TV kept the house nice and warm in the winter time, and sparked (!) my curiosity about all things electronic. During my high school years (1959-1963) I built tube-powered hi-fi amps, culminating in the design of a power amp that used the newly-developed 8417 beam power tetrode, and could produce 100 watts RMS output at about one percent THD. I arguably had the loudest stereo of anyone in school at the time. :)

While in high school, I developed some interest in computing after listening to a talk by someone from Sperry-Univac. At the time, I had an uncle who ran a juke box and pinball machine business, from which all sorts of used parts, mostly relays and such, came my way, especially Automatic Electric rotary stepping relays.

My senior high school science project was a sort of von Neumann architecture "computer" built from a bunch of those rotary stepping relays (they acted as memory), conventional relays (they were the glue logic—that term barely existed back then), a couple of telephone dials and push buttons to accept input, blinking lights (gotta have those!) and a binary-decimal decoder, also built from a pile of relays, that drove a crude 7-segment display made from automobile dashboard lights. It took me several months to build this contraption and several more months to get it to work right. When it came time to take it to school we had to rent a truck—it was too big to fit into the trunk of my stepfather's 1960 Chevy. :) I won first place in the school science fair, and third place in the state science fair.

After finishing high school, I enlisted in the U.S. Navy, where I encountered my first "real" computer, a tube-powered monstrosity at the Great Lakes Training Center Electronics School. This was a more-or-less general purpose machine, controlled by a Friden Flexowriter, and capable of performing a blistering 4000 calculations per second—about the speed of a cheap pocket calculator. It was installed in one of the few air conditioned rooms in the school. I don't recall how many tubes were in it but I do recall it had its own three-phase power source.

Aboard ship, I was part of the electronics gang responsible for maintaining the various radio transmitters and receivers, as well as radar and other assorted gadgets. During this period, the Navy started to acquire hybrid equipment, in which the lower-powered circuits were solid state and the rest tubes. I attended some special schools to learn how this stuff worked and how to repair it. It was clear to me even then that tubes were on their way out for anything other than high powered circuits.

As this ship was a World War II era destroyer, it had a main battery of six 5 inch guns in three turrets, which were capable of doing a frightful amount of damage (they also made the most unbelievable racket when fired). Controlling them was an analog ballistic computer, which received inputs from gyros, radar and other sources, and figured out how to aim the guns This system worked well enough that we could easily pick off targets over nine miles away, or knock out aircraft flying in the stratosphere. I think it was seeing this working example of processing power that led to my career with computers.

After leaving the Navy, I held a couple of electronics jobs and then, through some fortuitous circumstances, got a job working with a primitive computer system called the ZIP Mail Translator or ZMT. The ZMT was the U.S. Post Office's first foray into using digital technology to sort the mail. It interfaced to an electromechanical letter-sorting machine (which was almost as big as a small house), accepted a partial ZIP code and then routed the mail to one of 256 possible bins (hmmm...an 8 bit machine). Bin zero was the "error" bin, into which misdirected mail would go. During the debugging stages, the error bin frequently overflowed onto the floor. :)

I spent quite a bit of time programming ZMTs, as I had, for unfathomable reasons, developed an affinity for the crude machine code that told the thing what to do. Programming was, no surprise, done with a Tele-Type machine, which ultimately got the code written to a Ferro-Cube memory unit. The machine had 8K of memory—8 kilobits, that is.

After the close of the ZMT project, I got involved with traffic control equipment at another company, where my experience a decade earlier with my relay computer came in handy. While at that company, I concocted a bi-stable circuit that worked with two small relays and two diodes, acting as the electromechanical equivalent of a single input set/reset flip-flop. I was awarded (in 1975) a U.S. patent for the design. I also received another patent for the development of a traffic priority control circuit.

In the mid-1970s, another fortuitous circumstance landed me a job with a prominent supplier in the surface transportation industry. Among the many projects they had under development was an event recorder for use in locomotives, a device that paralleled the function of the flight data recorder found in commercial airliners. The original design was built around the Z80 MPU, but not too long after I joined the company, the 6502 had become available, and for much less money per unit. A new design built around the 6502 replaced the Z80 unit (which was three times as expensive to build and a royal pain to program) and that's where it got interesting.

The electronics engineers who were developing the recorder needed someone to write the software for it. One of them knew Z80 assembly language, but none knew the 6502 version. I looked at it and decided I could learn the language in short order. It wasn't as simple as it looked, but I persevered and soon mastered 6502 assembly language programming, using the reference assembler provided by MOS Technology. The event recorder was installed in all Amtrak locomotives and devices like it eventually became standard equipment on all locomotives in the USA and Canada, although later ones were not 6502 powered.

I stayed with this company for nearly 15 years, and in fact, wrote some software that ran on their IBM 360 mainframe, using FORTRAN and COBOL (ugh!). There was also a DEC PDP-11 there, on which was running UNIX (this was c. 1980). Needless to say, I spent plenty of time on that machine, as the UNIX environment was interactive, which was more than could be said about the IBM 360.

In 1983, a purchase was to play a role in my future career. I bought a Commodore 64 almost as a lark, just so I could say I had my very own home computer. BASIC was much too slow, so, knowing the 6502 assembly language, I started writing M/L routines to speed up BASIC programs. The following year, a life-long friend went into the automobile repair business and soon realized that using a computer would make it easier to run the business. The problem was an IBM PC was financially out of reach, and there weren't any good packages tailored to an auto repair business (some amateurish stuff had been written for the Apple ][, but was as bug-ridden as the beds in a skid row flophouse).

So I put together something for him that would run on a C-64 and that got him up and running. It was a mixture of BASIC and M/L, the latter mostly for sorting and searching. The following year, after the Commodore 128 had come out, I converted him to the C-128, and in the process, realized one could make some money doing this sort of stuff. That lead to the formation of my company.

In 1988, I got a job developing software for a truck leasing company, which was right after I had built my first UNIX server (powered by SCO Unix 3.2). This was supposed to be something I'd do during my off-hours. However, as I started cranking out code and demonstrating it to the client, they started coming up with more and more features to include in the finished project. It quickly became apparent I would be trying to serve two masters by working on the truck leasing system while employed full time.

So I sized up my financial situation (which was okay at that time), took a deep breath, quit my job at the transportation supply company and joined the ranks of the self-employed. Although lean times have struck now and then, I haven't looked back and have managed to make some money and occasionally have some fun. I've had the satisfaction of designing and installing a number of large-scale UNIX and Linux powered systems (one with nearly 50 users), as well as the scratch-development of several vertical packages.

Things changed a bit early in 2007, when I developed a potentially deadly immune system malfunction that has proved to be costly and difficult to treat. I jokingly refer to it as Pac-Man disease—for reasons that become obvious once the nature of the problem is understood—but it's no joke. For a time, I was too weak from the effects of rounds of chemo to work much, and between that and the medical costs that weren't covered by my insurance, I got financially upside down for a while. Things got even bleaker in early 2008, when my condition worsened and I skidded perilously close to the edge of the metaphoric cliff, only to be temporarily pulled back by surgery. Fortunately, a newly-released drug in August 2008 turned things around, allowing me to maintain a moderate work schedule while being treated. I've now been on this drug for three years and so far, so good. In all likelihood, I will continue to require it for the remainder of my life. And that leads up to how I ended up here at 6502.org.

In early 2009, I decided for health reasons to cut back on my work schedule and only take in projects that would not require months of planning and work to come to fruition—I wasn't sure that I could stay in it for the long haul. I also cut back on my server building business because the physical aspects of the work were becoming increasingly difficult to handle. With more time on my hands, I started looking for things to do that I could manage in my permanently weakened state. That's when I thought about trying my hand at designing and building a small computer. Naturally, with so many years of 6502 experience behind me, the choice of microprocessor wasn't hard. That's what got me started on my POC unit.

My ultimate goal is to build a 65C816 powered system capable of running a pre-emptive multitasking operating system fashioned along the lines of UNIX. Once I have a working kernel, I can develop all the tools that I think might be useful. I don't have any particular plan for how I might use the thing. The fun is in the building and problem-solving. I'm hoping this sort of project will keep my mind active and (more-or-less) fully functional as I head into the so-called golden years.

By the way, computers aren't all I do. My other principal interest is large-scale model railroading. Shortly before Pac-Man attacked, I scratch-designed and started building a one-eighth scale model of the EMD F7 Diesel-electric locomotive. At 900 pounds and with 16 horsepower, it can haul a train carrying 20 passengers. It's not finished, mostly due to the aforementioned health issues, but also because I keep tinkering with the propulsion system. This too will help to slow down brain rot as I age. :)
Edit: Forgot to mention that I'm a classically-trained double bassist, but mostly play blues, jazz and occasionally jam with the hillbillies.

Last edited by BigDumbDinosaur on Sat Oct 15, 2011 9:10 pm, edited 2 times in total.

 Post subject:
PostPosted: Fri Oct 14, 2011 12:42 am 
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Joined: Mon Aug 08, 2011 2:48 pm
Posts: 793
Location: Croatia
My life tales are yet to come... Who knows what i could end up doing whit computers and similar stuff for life...
Speaking about relay contraptions, i also done a few of them, and i remember that my mother was starting to complain about the awful noise, and relays are kinda expensive. But i always wanted to make a small 4 bit relay computer...
And about the tubes, i am kinda building also a EL34 SE tube amplifier(I even asked BigEd for advices :D), but i am not really a tube expert, I've already done a EL84 amp, and a magic eye tube vumeter (and i also had to try making some logic gates, and they worked :D )...

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PostPosted: Fri Oct 14, 2011 10:59 am 
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Joined: Thu Dec 11, 2008 1:28 pm
Posts: 3251
Location: England
Good to hear about your relay computer project BDD. When I was about 10 years old I was taken to see some student projects at a local college - there was a simple adding machine project there (using a rotary telephone dial for input), which had me baffled because I had some feel for lights and switches but no idea about internal state. Those stateful switching relays would have been good for me to see and learn from.

It seems that quite a number of people got started with training from the Navy. As it happens, I was aboard HMS Belfast yesterday and had a look at the ballistics computer - from the doorway. There are some good films online about how such things work, so I had some idea what I was looking at.


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