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Interested in a home brew Z80 computer project?

Did you post that write up before and I am just now finding it?

I took the photos some time ago but only got around to writing it up last night. The boards are being rushed to you as we speak. I thought a build using photos would be better than a description.

Still chuckling about the football team story.
 
James, as usual I'm sitting here with my mouth open; where the heck *DO* you find the time to come up with all this great stuff?
 
Wow! Things are really rolling fast now. Disk IO FDC CBIOS development and test is going at break neck speeds and PropIO is going just as fast! I am barely able to keep up with the testing! This is a really great problem to have!

Disk IO FDC support has never looked better and the bugs are being crushed left and right. There is still a nasty one embedded in there some place but it is fast running out of room to hide. The Disk IO can now read and write many files to the floppy disks and for most of them it seems to work fine. There are problems but they are repeatable so I think they'll be found before long.

PropIO is also blooming. Just tonight the VGA & PS/2 keyboard terminal interface got VT-100 compatibility from the PockeTerm project (Thanks James, Jeff, Vince, and others!). I think the uSD support is probably on its way soon too. There is so much successful reuse from the Propeller group that development goes quickly once the major infrastructure is in place.

Wow, what a weekend! I think I need to build another N8VEM SBC setup bench just to support all the testing. This is exciting!

Thanks and have a nice day!

Andrew Lynch
 
Hi! Just posted a fully functional but not optimized FDC CBIOS on the wiki for test. It seems to work fine and at least I didn't find a way to break it.

Please let me know if you are interested in building your own home brew computer. Soon there will be a full fledged FDC CBIOS for the Disk IO board to support floppy disks.

Thanks and have a nice day!

Andrew Lynch
 
lynchaj said:
Hi! Just posted a fully functional but not optimized FDC CBIOS on the wiki for test. It seems to work fine and at least I didn't find a way to break it.

Please let me know if you are interested in building your own home brew computer. Soon there will be a full fledged FDC CBIOS for the Disk IO board to support floppy disks.

Thanks and have a nice day!

Andrew Lynch
Click to expand...

Count me in, I always like to build project like this, and I am not too far from Jameco.

Dougtronics
 
Hi Doug! The first step is to sign up for the mailing list and wiki. Then you can get all the information you would like and build your own system. Probably by the time you get your PCBs and build them up the FDC CBIOS will be even better and you'll be able to use it for your home brew system.

There are several PCBs available such as the SBC, ECB backplane, ECB bus monitor, ECB prototyping board, DiskIO, Zilog Peripherals board, 6809 host processor board, etc. I have all the PCBs available for builders.

There are at least two other boards in active development such as the Video Display Unit (VDU) for composite video and PS/2 keyboard and mouse and the PropIO which is an intelligent IO controller and provides VGA display, PS/2 keyboard, and uSD media capability.

In addition, there are related projects such as the DSKY front panel debugger, Vince Briel's PockeTerm, and James mini-N8VEM SBCs. There are probably others as well but I'm having increasing difficulties keeping up since there is so much development recently.

All design information for hardware and software is freely and publicly available. The PCBs are available and low cost to encourage easy entry to the project.

Thanks and have a nice day!

Andrew Lynch
 
lynchaj said:
Hi Doug! ... There are several PCBs available such as the SBC, ECB backplane, ECB bus monitor, ECB prototyping board, DiskIO, Zilog Peripherals board, 6809 host processor board, etc. I have all the PCBs available for builders.
Click to expand...

Doug was by my place this morning to pick up some Kaypros I was giving away, and he bought my spare N8VEM cpu and backplane boards (I bought an extra set but a friend who going to build with me bailed so I didn't need them anymore), so he's on his way!
 
Hi! That's great! Just be sure that all new builders review the mailing list and wiki *before* they buy anything so they are fully informed of what they are getting in to. I recommend that any new builders thoroughly check out the N8VEM project beforehand on the wiki and mailing list and make fully informed decisions. Making your own home brew computer is a lot of fun and I am totally enthralled with it but it is not for everyone! Reviewing the trials and tribulations of our builders will help people make informed decisions.

Honestly though, there are few builders with genuine problems during build. A lot fewer than I would have expected. Only a few have required more than simple fixes to get going and almost all got their systems working on the first try AFAIK. This is both good and bad. Good is that builders are successful but bad in that there are so few new builders with problems to help. The few new builders with build problems about get mobbed on the mailing list with other builders trying to help.

I think its a bit like the MayTag repairman at times...

Thanks and have a nice day!

Andrew Lynch
 
lynchaj said:
Hi Doug! The first step is to sign up for the mailing list and wiki. Then you can get all the information you would like and build your own system. Probably by the time you get your PCBs and build them up the FDC CBIOS will be even better and you'll be able to use it for your home brew system.

There are several PCBs available such as the SBC, ECB backplane, ECB bus monitor, ECB prototyping board, DiskIO, Zilog Peripherals board, 6809 host processor board, etc. I have all the PCBs available for builders.

There are at least two other boards in active development such as the Video Display Unit (VDU) for composite video and PS/2 keyboard and mouse and the PropIO which is an intelligent IO controller and provides VGA display, PS/2 keyboard, and uSD media capability.

In addition, there are related projects such as the DSKY front panel debugger, Vince Briel's PockeTerm, and James mini-N8VEM SBCs. There are probably others as well but I'm having increasing difficulties keeping up since there is so much development recently.

All design information for hardware and software is freely and publicly available. The PCBs are available and low cost to encourage easy entry to the project.

Thanks and have a nice day!

Andrew Lynch
Click to expand...

Thanks, got you and how to sign up for the mailing list and wiki ?

Dougtronics
 
Hi! Thanks to my good friend James the N8VEM home brew computing project is offering its first ever “twofer” special.

If you purchase an N8VEM SBC PCB for $20 plus shipping for an additional $5 you will receive a special edition mini-N8VEM version 8 SBC PCB.

Why two SBC PCBs? At the N8VEM home brew computing project we have found that the best tool for building your own N8VEM SBC is to have its brother the mini-N8VEM SBC running along side!

I have both the SBCs and use both frequently for a variety of tasks as do several of the N8VEM builders. Believe me, you’ll get used to having both!

There are 22 mini-N8VEM SBC PCBs available and this special will only last as until the mini-N8VEM PCBs run out.

The N8VEM home brew computing project is completely amateur and non-commercial. All software and hardware design information is free and publicly available.

Please join us on the N8VEM home brew computing wiki and mailing list for more information!

http://n8vem-sbc.pbworks.com/

http://groups.google.com/group/n8vem

Thanks and have a nice day!

Andrew Lynch, 73 de N8VEM

PS, this is a video from an advanced N8VEM builder demonstrating his N8VEM SBC with optional ECB backplane, DiskIO board connected to an IDE hard drive and floppy drive, DSKY front panel, and ECB bus monitor all working simultaneously. You can see him running CP/M 2.2 and copying files from the IDE hard drive to the floppy drive. Notice the data streaming past the ECB bus monitor. The DSKY is displaying floppy drive Track, Sector, Status 0, and Status 1 from the DiskIO floppy drive controller.

http://n8vem.googlegroups.com/web/copy.avi
 
Hi Bill! Well, pretty much everything. The PCB just gets you a base to work from. You'll need to use the BOMs/parts lists to find all the parts you need and then assemble the SBCs. You'll need a 5V power supply (regulated) and various tools and test equipment.

It may sound complicated but really it isn't. Once you build the first one the rest is pretty easy. Feel free to ask lots of questions. There are several new builders with low experience but that doesn't seem to stop anyone. As soon as they see the first boot sequence they climb up the learning curve pretty quickly.

Thanks and have a nice day!

Andrew Lynch
 
Hi! Just a quick update on N8VEM home brew computer project. The VDU board PCB is testing good. I built one of the units from the PCB and it seems to be working. The video display and keyboard interfaces are all functional.

What's next is writing some software so the VDU will be useful as a display. Ideally it could be used as a local terminal replacement. Then a PC or laptop would not be necessary any longer since the N8VEM with VDU board would be self contained. All the builder would need to add is a composite monitor and PS/2 (AT) keyboard.

Thanks and have a nice day!

Andrew Lynch

PS, I uploaded some pictures of Dan's VDU and also my VDU board working. They are in the N8VEM wiki VDU folder.

http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder&param=VDU
 
Hi! Just a quick update. Tonight one of the N8VEM builders (Dan) posted a ROM image that allows the N8VEM system to boot up "locally" to use the VDU for video and keyboard with no PC or terminal used for anything. For the first time ever, my system came up completely on its own with no outside components at all.

That was pretty neat since everything it used, save the power supply, video monitor, and PS/2 keyboard was made from scratch. It is a lot of fun making your own home brew Z80 computer. Neat things are happening all the time.

Here are some photos from another builder (Nik) who has built an N8VEM system and has posted some nice photos.

http://picasaweb.google.com/Brizza62/DropBox?pli=1#5398630559881327458

If anyone is interested in building their own home brew Z80 computer please contact me. I still have many PCBs available.l

Thanks and have a nice day!

Andrew Lynch
 
Hi! There are some new developments on the N8VEM homebrew computing project I thought to pass along. I have plenty of the existing low cost PCBs so if you would like to build your own homebrew computer please contact me. The current PCBs are the Z80 SBC (serial, parallel, RTC, 512K RAM, 1MB ROM), ECB backplane, ECB bus monitor, ECB prototyping board, DiskIO (FDC & IDE), Zilog Peripherals (CTC, DART, dual PIA), 6809 host processor, and VDU (composite video with PS/2 keyboard, mouse, and parallel printer interfaces).

The PCBs for the 6809 IO mezzanine board have arrived. I am building one now for testing and am waiting on some parts. The PCB allows the 6809 host processor to operate either independent of the ECB as a stand alone computer with 9VDC adapter or as a ECB 6809 host processor with enhanced IO. The 6809 IO mezzanine includes ACIA serial port, two VIAs for parallel IO and timers, a MC6840 PTM for ASSIST09 compatibility, and an external bus interface for its expansion. One of the N8VEM builders has ported Dave Dunfield's CUBIX to the 6809 host processor and hopefully soon that will be running on the 6809 host processor with IO mezzanine support.

Soon there should be a N8VEM PropIO board and the PCB manufacturing order going out probably later today. This board provides two Propellers that connect to the ECB and can communicate with the SBC. The Propellers have their own EEPROMs and either PropPlug or serial programming interface. The first Propeller has VGA, PS/2 keyboard, and microSD interfaces. There are pads on the PCBs for a 3M microSD socket (SMT) and the Sparkfun microSD breakout board so you can use either one. The second Propeller also communicates with the SBC over the ECB but the remaining unallocated pins are brought to a header for builder expansion to the on board prototyping area and/or the mezzanine prototyping board.

Work continues on a new board with color graphics and sound using TMS9918 color graphics chip and probably AY-3-8910 sound chip. There are some working partial prototypes and even some demonstration software with photos on the wiki. More development and prototyping to happen soon followed by a PCB. The TMS9918 board uses a novel low part count design with SRAM rather than DRAM.

One of the builders has created his own N8VEM chassis and posted detailed instructions with photos on the N8VEM wiki. There has been a lot of work on builder "how to" instructions by consolidating all the pieces of information into a single document. There is an updated SBC ROM image that supports booting from IDE, ATAPI, floppy drives, or ROM. The ROM image supports regular serial terminal IO interface, DSKY "front panel" support, and/or the VDU with PS/2 keyboard for completely independent operation.

There is a lot of activity on the N8VEM homebrew computing project and any and all are welcome to participate. Join us on the N8VEM mailing list and wiki. I think you'll have a lot of fun!

Thanks and have a nice day!

Andrew Lynch

PS, at long last there is a wikipedia article for the N8VEM!

http://en.wikipedia.org/wiki/N8VEM
 
Hi! Major progress on the N8VEM Color Graphics and Sound board project! Last night I was able to get the TMS9918 prototype working and duplicate the results of another builder. Now there are two TMS9918 prototype boards working with the SRAM modification. Now that the basic design appears solid, we will be further modifying the prototype to include AY-3-8910 sound chip for MSX audio compatibility. There are some refinements to the TMS9918 circuit and possibly adding a SPO256 speech processor and/or SN76489 if PCB space allows.

There are some pretty neat photos on the N8VEM wiki in the "color graphics and sound" folder if you would like to check them out. It is very exciting development and major progress along the way to adding color graphics and sound to the N8VEM homebrew computer.

Thanks and have a nice day!

Andrew Lynch
 
Hi! The PropIO PCBs have arrived. These boards connect to the ECB as per the other N8VEM boards. They have two Propellers that communicate with the SBC Z80. The first Propeller provides VGA display, PS/2 keyboard, and microSD interface. The second Propeller is unallocated and exports its pins to dual row header pins along with 5V, 3.3V, ground, etc.

There is a small PTH prototyping area for builder experiment expansion on board and provisions for a larger mezzanine style prototyping board for larger circuits. The mezzanine prototyping board would connect to the dual row header pins by an elevated female socket for sufficient PCB to PCB clearance, heat dissipation, etc.

The PropIO boards are available for the usual N8VEM. You can either build the PCBs yourself using the information on the N8VEM wiki/mailing list or for $20 each plus shipping.

Thanks and have a nice day!

Andrew Lynch
 
Hi! Several builders have their PropIO boards. The initial reports of build and test are starting to come in and things are looking good. The VGA and PS/2 keyboard interfaces are working. The N8VEM SBC can communicate with the PropIO and the PropPlug seems to be working. Basically this means that the essential functions of board are working. Some minor issues may still be found but things are definitely looking good now.

I am building my own PropIO and received the last of the parts yesterday. I am hoping to do more building and testing this weekend. Next will be to make the programming cable and program the Propeller with the PropIO software, burn the SBC ROM, etc. This is a fun project!

There are still several PCBs available if anyone would like to get in on the build and test phase. I suspect we'll probably need a PCB respin to incorporate all the changes and new features requested although I may just run another batch of these PCBs to help spread out the testing.

Thanks and have a nice day!

Andrew Lynch
 
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