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[redrumloa]

P112 Single Board Computer Kit

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.

Features
Dimensions: 130 x 100mm (5.1 x 3.9 inch)
Support for 5.25 and 3.5 inch diskette drives (up to 4 drives, mixed types)
Z80182 CPU at 16MHz (12.228, 18.432 or 24.576MHz optional)
32kB flash ROM, in-board reprogrammable
64kB SRAM, upgradeable to 1MB
Real-time clock/RAM, with on-board battery
5 (yes, five) serial IO ports, 2 as PC-AT compatible connectors, 3 as TTL outputs
Parallel port, IBM compatible, with bidirectional ability
Bus expansion/logic analyser socket
Software included:
Shareware DOS+ and CCP+ (replace CP/M)
Shareware PPIP (replaces PIP)
Shareware UUENCODE & UUDECODE
BIOS support for diskettes, parallel & RS232 serial ports
ROM monitor, including debugger
Utilities:
ASCII file-transfer (eg UUENCODEd)
Disk format
In-system flash-ROM reprogrammer
Real-time clock sample code
All source files
All code (except the shareware items noted above) is offered under the GNU General Public License.

Pretty neat the guy is selling them for
60 remaining. $120 by money order ($125 by Paypal). Not a bad deal! May get one in a couple months. :-)

[motorollin]

Can't get to the site :-( What could you do with hardware like this?

--
moto

[redrumloa]

Try this one, it is the original designer's webpage.

This board is a single board computer, a 3.5 floppy drive form factor. With it you can can run old CP/M software, essentially. I could see this being used for various hardware projects, besides just retro computing though, With it's small form factor, low power consuption and ease of programming CP/M it could be put to various tasks. Me? I'd play with the CP/M on hardware multiple times faster than my C128, or my Televideo TS-803H for that matter. :-)

[motorollin]

Cool! But I think I would prefer a C64 as I'm not familiar with CP/M. Especially with the 3.5" disk drive as part of the unit :-)

--
moto

[Tripitaka]

If a C64 can fit in the base of a joystick then I'm sure a 3.5" form factor could be done easily enough.

[blobrana]

Hum,
a computer inside a floppy disk....


(but i can see problems there...)

[InTheSand]

Hmmm!

How compatible is the Z80182 with the original Z80 and CP/M stuff?

Many moons ago, I wrote a basic Z80 OS for a board I pulled out of a multi-user CP/M machine... I then got it running a few years ago on a Z180-based board, so it'd be good to get it running on something else.

Shame the original link appears to be dead...

- Ali

[InTheSand]

blobrana wrote:
Hum,
a computer inside a floppy disk....

Not quite a computer inside a disk, but the Z180 board I mentioned above was inside a Cumana disk drive designed for the Amstrad NC100 range of Z80-based portable micros that were briefly popular in the UK around the early 1990s...

The board contains the CPU, an EPROM, a RAM chip and the disk controller IC. It's very small, and in order to save space, the Z180's address and data lines are a bit scrambled! I built a nice messy "EPROM unscrambler" to descramble the EPROM's contents... Should have done that in software, I guess!!!

The drive is about the same size as an external Amiga drive, maybe slightly longer. It has a 9-pin RS232 serial port on a flying lead, and an input for DC voltage.

The odd thing is that, in terms of basic CPU power, the disk drive had more grunt than the computer to which it was connected...

- Ali