Short for fpga assisted processor, fap was originally designed with numerous throughhole components on breadboard and perfboard below, left before being redesigned with smt and custom pcbs. The idea being that i perhaps may then reuse some of the old 816bit isa pc cards, like parallel ports, network and perhaps even video cards i have some 816 bit parallel, serial and network cards i just have no idea how hard it is to reverse engineer these card to a degree that i could write the drive code. Vga card graphics card video adapter cards drivers driver agp ddr manuals bios adapters chipset pci slot information driver info manual agp ddr. The z80 board itself will be the basis for olduinoz but the front panel will be great for testing. The goal i would like to achieve in this matter is to have a very simple and intuitive interface form the programmers point of view. Ben eaters computer isnt really what you would think of as a computer like a raspberry pi. I recently built a mame arcade cabinet from scratch. Dana myers has added a new log for evaluating a simple 1wire master driver. I have an old isa vga card pictured its marked ct8490 magic vga. Now that the homebrew z80 computer is working like a charm, something was. I am considering making an isa interface onto my homebrew 8bit z80 computer. Usually computers want a very fast interface to the graphics card hence why we kept sticking graphics card in special buses that are faster than all others.
April 18, 2017 changed my mind, will try to build a z80 based more home. Its based on the z80 processor, clocked at 10mhz about 3 times faster than was typical in the z80 s heyday, has 512kb of ram hence the name and 8kb of rom. Sign up no description, website, or topics provided. Aug 20, 2014 this is a demo video of my homebrew z80 microprocessor based computer. The vga board prototype is finished now including parallell to serial interface. Jul 06, 2015 the compact flash card interface is exactly the same as normal except instead of using 16bits of data the card exchanges 8bits of data at a time. It is not a clone of anything specific, but there are suggestions of the zx81, uk101, s100, superboard ii and apple i. It is much longer than necessary as it is built around kyedos so all the vgakeyboardsd drivers are there ready to be used. Not just any computer, mind you, but a fabulous z80 machine, complete with video out. Ultimately id like to do things like have the z80 send a message to reload a new program into the propeller to change from say a vga text driver to a vga graphics driver. Proved to be not as simple 8086 timing is a bit different from z80 timing and you need some more address lines but after that was solved it was just a matter of reverse engineering the bios code to get the card to display anything at all standard vga is not standard vga and standards are there to be tread upon. If we assume that vga signal generation is a solved problem handled by a black box, how do you connect this black box to the cpu.
Designing the rhococo retro home color computer hardware. Interfacing old pc cards to homebrew 8bit computer page 2. Fap80 is a homebrew computer built with zilog z80 cpu. Aug, 2014 notice that the octal latchs clock input 74ls373 pin 11 is activehigh while the z80s write enable pin wr pin 22 is activelow. Best tool for self learning the basic of todays computer. I had been using the interface from my ft847 with the addition of a usbtoserial. I do not remember if the original pc buffered the isa bus from the microprocessor bus but this is easy enough to do.
This weekend we decided that the time was ripe for developing a video interface. Software installing cpm3 on the ide diskcard in order for this ide card to be of any practical use we need to install cpm and later, other disk operating systems on drives interfacing to it. The program listings are provided with instruction hex code. And the op is a little off with the math because a vga text based doesnt take that much ram. Rc2014 mini single board z80 computer kit from rfc2795 ltd. At this point separate 8kb of the display card memory is accessible to the main z80 cpu and its nmi is called to alert about this. The demonstration programs were written in assembly program using z80 instructions.
This project has been on hold since starting another project that dominated my life. It comes with a 48key keyboard, 128k ram, and vga 320 x 200 64 color graphics, a speaker, and an sdcard slot for storage, basic, oh and it has a joystick port. Jul 17, 2014 however, even without it, i hope to achieve troughput of about 200. Students can enter the program by using hex code to the memory and. These rom images are for the sbc v1v2 z80, zeta sbc, and n8 boards.
There are a fair number of components so it took a while to assemble but lees layouts and labelling are exquisitely good and the assembly notes cover most tricky bits. Uploaded on 4142019, downloaded 6165 times, receiving a 96100 rating by 31 users. This set of articles describe its design and implementation. It generates a reset pulse on switch on and when the cpu busrq signal goes high. How to add any video display to ben eaters 8bit homebrew. Usb rig interface david smith vk3hz i needed a new rig interface for portable operations with the ft817 and a laptop. Driver source files are separate from the bios and new drivers are easier to implement. So far ive kept the interface dead simple, and use a pio and bitbanging to do all the bus signals, though ill probably have a go at marrying this up closer to the z80 bus directly to speed up larger transfers. The biggest problem synchronization between z80 writes and atmega reading was resolved using 7474 flipflop as planned before. The z80 cpu board circuitry the complete schematic of the prototype board can be seen here.
Atmega328 source code in assembler is available upon request. I built a homebrew z80 based 8 bit computer for retro challenge back in 2014 hence the name rc2014. At the moment its very simple but id like to try to interface it to a 1980s vga card. This lab book is designed for selflearning how to program the z80 microprocessor in machine language with the z80 microprocessor kit. It is not a clone of anything specific, but there are suggestions of the zx81, uk101, s100, superboard ii and apple i in here. The compact flash card interface is exactly the same as normal except instead of using 16bits of data the card exchanges 8bits of data at a time. Fap80 is a homebrew computer built with zilog z80 cpu designed over the course of a year dekunukem built twice. The development of a simple homebrew z80 processor board which im using as a learning process. The memory interface to the z80 with a fpga is easy because it can instantly respond on the bus, and such vintage cpus have very simple buses so its not hard to implement. At first it does look a bit scary, but once you split it into its components it gets a lot easier. Projects, homebrew z80 systems software development tools assemblers.
It uses serial to communicate with the outside world, so plugging it in to a laptop with a ftdi lead means you can open up putty and start programming like it is 1982. Software installing cpm3 on the ide disk card in order for this ide card to be of any practical use we need to install cpm and later, other disk operating systems on drives interfacing to it. The z80 membership card the membership card is a complete computer that fits in an altoids tin. Set of seven tables organized by opcode for all of the z80 s instructions. It differs from existing z80 implementations in that it is designed from the groundup through the schematics and lowlevel gates. Vga graphics card video adapter drivers driver agp ddr manuals bios adapters chipset pci slot information driver info manual agp ddr. This is a demo video of my homebrew z80 microprocessor based computer.
This variant of the controller provides six modes of display, depending on the resolution chosen. It differs from the existing mostly verilog z80 implementations in that it is designed from the groundup through the schematics and lowlevel gates. The z80 microprocessor kit is designed for selflearning how to build and how to program the z80 microcomputer. I use this to program the main memory via the switchboard, until such time as the computer can be programmed in a more convenient way by the keyboard. Xmonsterz80 a 24mhz z80 work packed with video features, ide hard drive interfacing, and super cool operating system that i have yet to start developing power schematics. Its based on the z80 processor, clocked at 10mhz about 3 times faster than was typical in the z80s heyday, has 512kb of ram hence the name and 8kb of rom. I am attempting to make a retro computer using a z80 and ideally would like to give it the ability to boot from an sd card. The purpose of this page and its sub pages about members of z80 family and. I have an old isa vga card pictured its marked ct8490 magic vga and uses the cirrus logic gd510a chipset. I might buy a small lcd board with an sdsd1963 on it for experimentation and development, but ultimately i want to be able to plug in my monitors vga or other.
Though it only takes a couple of seconds to load up a full 32k the biggest challenge has been to port cpm. Learn ti83 plus assembly in 28 days z80 instruction set, by sean mclaughlin. The lm512 is an 8bit microcomputer which i designed and built over the course of 20 and 2014. Vga single chip driver for windows 7 32 bit, windows 7 64 bit, windows 10, 8, xp.
An lcd interface to the z80 without using any programmable io chips. An 8bit ide interface although there are now technically simpler storage options for hobby projects, the 40 pin ata ide interface is still a ubiquitous, well documented connector which allows hard drives and compact flash cards via a simple adapter to be used. Today i assembled the front panel board of lee harts z80 cpu kit. This variant of the controller provides six modes of display, depending on the resolution chosen 640x480 vga or 800x600 svga and the color.
Proved to be not as simple 8086 timing is a bit different from z80 timing and you need some more address lines but after that was solved it was just a matter of reverse engineering the bios code to get the card to display anything at all standard vga is not standard. The kit is great, functions perfectly, is easy to assemble, and arrived in a very sturdy package. Rc2014 mini single board z80 computer kit from rfc2795 ltd on tindie. Im not sure what you might need to know, so the cpus are the z80 or the 8088.
Hdmi and displayport would require far too much of this. During display draw the z80 bus request is called to put the display card cpu into hibernation so that the memory can be accessed freely by display refresh logic. The z80 refresh function is masked out, the reason is the unnecessary. For a year or so now im designing a super simple z80 based retro home computer called rhococo retrohomecolorcomputer that has graphics and sound capabilities resembling a c64. On the mainboard are two uarts enabling a modern computer to act as a dumb terminal, a real time. You idea of interfacing a z80 home brew computer to the isa bus is excellent. Yes i would love to build a vga video card using an fpga. I knew, have seen examples, that you can implement a vga video driver with. Rc2014 is a simple 8 bit z80 based modular computer originally built to run microsoft basic. Jun 22, 2019 i am considering making an isa interface onto my homebrew 8bit z80 computer. Aug 30, 2015 today i assembled the front panel board of lee harts z80 cpu kit. Otherwise its a standard z80 circuit interfaced with static ram, rom and the.
However, if you can live without building the hardware yourself, a z80 computer that you program yourself is completely possible. Set of seven tables organized by opcode for all of the z80s instructions. So now it just comes down the how to connect the compact flash card to our system electrically. The n8vem home brew computer project z80 sbc rom images. I am 100% set on using a z80 and do not want to use a microcontroller with an internal spi hardware interface.
The z80 bus stm32 interfacing is something i need to look into, yes. This is accomplished by an eight bit bus driver 74ls245. The z80 membership card an altair in an altoids tin. This is perfect for us since the z80 can only handle 8 bits of data per transaction. The membership card is a complete computer that fits in an altoids tin. Interfacing old pc cards to homebrew 8bit computer page 1. Hello, ive finally got my z80 homebrew machine going its only 25 years since i first wanted to build one. I hope to get back into regularly posting once or twice a week. A z80 from the ground up az80 is a conceptual implementation of the venerable zilog z80 processor targeted to synthesize and run on a modern fpga device.
The project is still under construction, but some functionality can be allready seen on the video. Teensy z80 homebrew computer part 5 implementing preemptive multithreading posted on february 1, 2015 by domipheus this is the fifth part of a series of posts detailing steps required to get a simple z80 based computer running, facilitated by a teensy microcontroller. Interfacing and testing rom chips part 2 z80 computer. I simply recommended checking out the propeller because its used in many homebrew computers for text and graphics output. The sram will probably have to run at 100mhz to be shared between these functions. However, the reliance on a computer does somewhat take away from the appeal of this little computer.
Inspired by classic 8bit computers like the altair 8800 and heathkit h8, it is thoroughly documented and easy to build, with big parts, big pads, and big traces and spaces. Vga card graphics card cards video adapter adapters. If you are interested in a z80 kit, i advise this kitcompany very much. It is inspired by the home built computers of the late 70s and computer revolution of the early 80s.
Most modern computers have much more in the way of hardware peripherials. How do you install a monitor on a homebrew computer. Z80 8bit compact flash card interface z80 computer project. Contains both an html version of the enclosed table and a gif image of the z80 machine code quick reference. You will have a very hard time building your own computer based on the z80 with all the features that you described. How do i build a computer with a z80 microprocessor.
Most recent revision dated mar 3 2011, again dec 12 2019. I have an old isa vga card pictured its marked ct8490 magic vga and. Intelligent peripheral controller a z80 with sio, ctc, pio, watchdog. The reset circuit also comes directly from the original z80 project. You need to invert the wr pins output by either using my npn transistor 2n3904 inverter solution as seen in the schematic, or you could use a 7404 hex inverter. The z80 microprocessor kit is designed for selflearning how to build and how to. Oct 30, 2014 49 thoughts on a graphics card for a homebrew computer generic human says. In late 2008 this material was moved from my s100 and cpm web pointers page. Clearly there must be a system on the new cf card or you must do the swap where another drive is the current system drive. Its basically just a processor with its own instruction set. Interfacing and testing rom chips part 2 z80 computer project. Z80 homebrew computer with vga and ay38912 sound youtube. The project is still under construction, but some functionality can be. Anything interfacing over i2c or spi might be possible, but youll have to add some kind of parallel driver ic.
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