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i would like to make a cp/m capable computer

R

redhawk579

Experienced Member
Joined
May 9, 2011
Messages
95
Location
new jersey
hello all,

I would like to build a computer using either the intel 8085 or motarola 68000l10
but I have very little experience in programming and moderate soldering experience.
i would hope that a senior member could lead me in the right direction on putting
together a microcomputer capable of the task(s) i will require of it.

sincerely,
redhawk579
 
redhawk579 said:
what is the z80 board under in the front page
Click to expand...

That's the N8VEM computer - it's a sort of group project to design and make a z80 computer that can run cp/m from parts generally available today. You buy the bare PCB boards, then all the parts and solder it together. There's a google group in addition to the web site listed above: http://groups.google.com/forum/#!forum/n8vem

The first project done is the N8VEM, with the ECB style backplane, which all the other boards plug into. There is a Z80 cpu board that can be plugged into it, along with other alternate cpu boards, a 6809 one that can run Cubix, and a 6502 based board also. There's a quite a few other additional boards available also.

There's also a new all-in-one board project called the N8-2511 that combines a lot of the most popular features built onto a bigger motherboard, so you don't have to add a lot of expansion boards to have a fully useful system. It's in prototype stage right now.

And, there's also S-100 boards being designed, so you could build your own S-100 based computer from bare boards - there's the usual Z80 cpu & peripheral boards, but someone is also working on a 68000 based cpu board. Don't know what OS it would run though - check the google group.

Jeff
 
Last edited:
Hi! To make an N8VEM SBC V2 all you need is a single PCB. It can run in a "stand alone" mode with Z80, RAM, ROM, serial port, and parallel expansion.

The basic board supports RAM and ROM drives and if you want more drive space you can add a PPIDE to connect an IDE hard drive or CF adapter.

Thanks

Andrew Lynch
 
Hi,
The basic SBC V2 uses its serial port for console IO so you'll need to connect either a serial terminal or a PC running terminal software. Old laptops running HyperTerm or other terminal programs work just fine.

If you'd like to connect to a TV for display you'll need an optional display board like the VDU, SCG, etc. Those board are connected to the SBC through a bus backplane board.

Here is a good tutorial one builder wrote. It gives a pretty clear explanation of how to build your own.

http://n8vem-sbc.pbworks.com/w/brow...ram=Building the N8VEM for the Total Beginner

Thanks!

Andrew Lynch
 
When you enter this world, there is nothing standard. It's going to take a lot of persistence and hard work to get very far.
 
You may want to look for a kit, then go from there. You can certainly make your own from bare parts, maybe a kit will be best. Seach for Z80 based computer kits and you should turn up some modern ones for sale (as well as vintage ones).
 
What sort of tasks are you hoping to accomplish with it? If you google around there are documents on a few different systems or clones like the Sym-1 there are a few folks here who did make their own 8085 single board computers but that takes a deeper understanding behind electronics and computer design. Not impossible though.

There are even some kits out there like the replica-1 (Apple 1 replica) or MicroKim (kim-1 clone) that are pre-created but kit form where you can solder and build it yourself for a cheap price. I think they've gone up in price over the years but there were even some ZX-81 kits out there which were originals in the box for under $200.. I would guess they may have gone up in price since then but that's an original not a replica.
 
I don't want to make a bunch of assumptions here...is the poster of this thread experienced in general with soldering boards, building circuits, etc? Used CP/M before? Have any vintage computer gear from the CP/M era that inspired this project in the first place? It's relatively easy to build a kit-based cp/m SBC if you have some experience with electronics and a nice place to work. Tell us more about where you're coming from sir.
 
I have done a soldering work and de-soldering work. I have used cp/m a little bit and watched some videos. I am interested in cp/m and in working on board level electronics for its educational value and for fun. I chose the 8085 because I found that like the z80 it needed few support chips and only 5 volts of current for power.

what i am trying to do is make a sbc running cp/m that can support 2 floppydrives and can use a display or could be rigged up to a xt-class machine to act as a terminal.
 
redhawk579 said:
what i am trying to do is make a sbc running cp/m that can support 2 floppydrives and can use a display or could be rigged up to a xt-class machine to act as a terminal.
Click to expand...

Hi
There have been several N8VEM builders who have done exactly what you describe. However, if you would like to expand beyond the basic SBC functionality for more IO like floppy drives, IDE, video, sound, graphics, etc you'll need an ECB bus backplane and the appropriate ECB board. The N8VEM system is modular so you can start small with a self contained SBC and optionally expand to include other hardware as you see fit.

As Jeff mentioned we are working on an "all in one" SBC at the moment but as you'd expect it is vastly more complex than a simple SBC. I expect to clean up the current prototype and have final boards out later this fall depending on how things go.

Thanks

Andrew Lynch
 
redhawk579 said:
so all i need is the n8vem main board and a terminal to start
Click to expand...

Hi,
Yes, however you build the N8VEM SBC V2 from the bare PCB. You supply your own components and assemble yourself.

This is how most builders start. They build and test the basic N8VEM SBC and once they get it running, add in the bus backplane, add in various peripheral boards, etc.

Any old PC with a real serial port will work as a serial terminal or you can use an actual serial terminal.

Thanks!

Andrew Lynch
 
Either connector are fine, he's just referring to some systems that are new and have no serial port anymore. Some USB->serial converters don't actually emulate all the signals properly which can cause some devices to not recognize that they're connected via serial.
 
What i wanted to do was build a 8085 computer. I really wanted to build from scratch it does not have to run cp/m off the drawing board though ,and i know that a few members have done what i am setting out to do. Now I have a few things to work with. I just ordered a 8085 and 8155 as a support chip ,and what I want to do is get info on the chips so I can test them then move on to bigger and better things (running cp/m)
 
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