P112 Single Board Computer Kit

This site is a mirror. The original can be found at http://www.cs.csubak.edu/~dgriffi/proj/p112/

Latest News as of May 10, 2006.

The P112 mailing list is a place to talk specifically about the P112 board.

The P112 subject pops up fairly often on the Usenet newsgroup comp.os.cpm. Reading it will help you get the most out of your P112.

Assorted pictures of my P112.

What is it?

The P112 is a stand-alone 8-bit CPU board. Typically running CP/M (tm) or a similar operating system, it provides a Z80182 (Z-80 upgrade) CPU with up to 1MB of memory, serial, parallel and diskette IO, and realtime clock, in a 3.5-inch drive form factor. Powered solely from 5V, it draws 150mA (nominal: not including disk drives) with a 16MHz CPU clock. Clock speeds up to 24.576MHz are possible.

The P112 board was last available new in 1996 by Dave Brooks. His page is here. In late 2004 on the Usenet Newsgroup comp.os.cpm, talk about making another run of P112 boards was discussed. I decided to step forward. With Dave Brooks blessing and the assistance of others, new boards were fabricated.

How do I get it?

The Second Run of P112 boards has finished. I have approximately 26 left. The plan now is to build up stock so I can ship immediately. Due to the rise in prices of everything thanks to gasoline prices, the price for a kit is now $160 by money order ($165 by Paypal) for shipment to the continental United States. Outside the US, I'll need to check shipping rates. In either case, email me before sending payment.

Nice! Tell me more!

This P112 board project is very different from the one Dave Brooks offered. The board itself is the same, but that's about all that stayed the same. The "native" operating system is now ZSDOS, an enhanced replacement for CP/M 2.2. The old DOS+ boot disk can still be used, but is discouraged. UZI-180, a Unix clone for the Z180 processor is available in a version specifically customized for the P112.

Instead of getting just a board with surface-mount parts mounted and little else, buyers get a complete kit. Except for a chassis, power supply, floppy drives, and tools (like soldering stuff); you get everything you need to get started. The documentation has been pulled together into a single PDF file, updated, edited, and cleaned up. A copy of the Walnut Creek CP/M CD dated Nov 1994 is included. No permission was needed to replicate it. Another CD is provided which contains the documentation PDF and lots of other stuff that was deemed interesting (like UZI-180).

I want one, but I don't want to build it myself.

No problem! One of my cohorts, Terry Gulczynski, will build and test your P112 for you. He has other services like adding more memory and adding an IDE interface. If that's what you want, please tell me when you email me.

Check out his website at http://home.cfl.rr.com/tgcons/ for more information.


Dated Wednesday May 10, 2006, this is the release version of the P112 manual.
Latest draft of the documentation in Postscript format.
Z-System boot disk image. Dated November 30, 2005.
Z-System source code disk images. Dated November 30, 2005.
This is a NetBSD package which downloads, configures, and installs cpmtools. It's the cp/m equivelent of mtools. If you have write-access to the NetBSD pkgsrc tree, please email me. I'd like to get this added.
Taken from RedHat Linux 6.2, this is used for copying disk image files to disks. Linux, *BSD, and other Unix users should use dd(1) instead.

The following disk images are retained for hysterical raisins.

Z-System boot disk image. Dated November 11, 2005.
Z-System boot disk image. Dated October 30, 2005.
Z-System boot disk image. Dated October 22, 2005.
Z-System boot disk image. Dated October 18, 2005.
Z-System source code disk image. Dated November 11, 2005.
Z-System source code disk image. Dated October 22, 2005.
Original boot disk image from 1996.


TG Consulting is where you'll find Terry Gulczynski's writings. Terry created the new Z-System with ZSDOS for the P112 and updated the boot rom. He is also producing an IDE interface board for the P112. Yes, you can now connect a hard drive to your P112.
Dave Brooks is the designer of the P112.
Hal Bower did lots of stuff in 1996 and now to help the P112 be all it can be. Lots of CP/M tools and information can be found at his page.
Professor Feedlebom was enormously helpful in getting stuff to and from the board-manufacturer and board-stuffer, and with financing.
Daves Old Computers - Disk/Software Images. Boot disks for lots of different vintage computers are here. It's not nearly the size of Don Maslin's lost archive, but it's a start.

If you have any questions or comments, feel free to email me at dgriffi;at;cs.csubak.edu.

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This page was last updated on May 10, 2006