This is the information and ordering page for a very limited number of P112 Single Board Computer kits we are making available for experienced electronics enthusiasts (who will need to be able to solder 2x 100 pin SMD chips).
The kit above is what will be mailed to you.
A a fully operational P112 built from this kit.
The P112 is a stand-alone 8-bit CPU Single Board Computer. Typically running CP/M or a similar operating system such as ZSDOS, it uses a Z80182 (Z80 upgrade) CPU with up to 1MB of SRAM memory and can interface with standard floppy drives, and also (via a D-GIDE daughterboard) it can support IDE hard disks, Compact Flash drives, and optical drives. Designed by David Brooks in 1996, it is possibly the first homebrew "SBC". According to Dave Brooks's website, the P112 design was released to the public domain under the GPL v2 in 2016. For anyone interested in CP/M and simialr operating systems the P112 will offer an authentic and enjoyable way to explore a wealth of vintage software.
Having fabricated a very limited number of P112 PCBs we have decided to make them available as kits as along with all components necessary to build working machines. We have constructed and tested the kits and components, and the P112 boots well to floppy and also to IDE HDD (via a D-GIDE daughterboard). If you manage to get a P112 up and running then I highly recommend purchasing a D-GIDE P112 kit from TG Consulting in order to attach IDE drives to your sytem, though this is optional.
Just to be clear: This is an opensource project (we did not design it) and aside from any fault in the parts provided we can not promise support with construction or use of the P112. You are wlcome to ask but if you require assistance you may need to ask for help in an appropriate public discussion forum or elsewhere.
P112 Specifications:
CPU: Z80182 (Z80 architecture)
RAM: 1MB (55 ns Alliance Memory AS6C4008-55PCN)
FLOPPY DRIVES: Two floppy ports (up to 4 floppy drives), using the FDC37C665GT floppy controller.
SPEED: Typically 16MHz in default configuration (but up to 49.152MHz MHz with the right crystal and settings and fast enough RAM).
REALTIME CLOCK: Battery backed-up Realtime Clock (via DS1302 RTC chip)
POWER: 5v, ~200mA.
CONNECTIVITY: 2x RS232 compatible serial ports + 3 additional unbuffered signals for the spare CPU ports + Parallel port.
IDE DRIVES: Supports IDE drive expansion board (obtained separately) through the J1 bus expansion port.
OS SUPPORT: CP/M, MP/M, ZSDOS, UZI180, etc
This kit is for experienced electronics enthusiasts only! You will require experience with complex SMD soldering to successfully solder two 100 pin QFP-100 chips (a SMD miscroscope is practically mandatory).
You can order a P112 kit using the payment options below.
P112 4-layer PCB (1.6mm thick, measuring 130x100mm).
All components necessary to build a working P112. See Packing List for full list of parts provided, along with some notes on the components.
The ROM has been pre-programmed with the latest BIOS for the P112 (version 6x02).
Kit construction notes:
The PCB is provided bare and there are no pre-installed parts.
Take your time to ensure you are able to solder the two QFP-100 chips to the board and double-check their correct positioning and orientation.
Aside from the info provided on this page there is no construction documentation provided with the kit. Please refer to Dave Brooks' original assembly instructions as well as Dave Griffith's more recent Assembly and Operation Manual for the P112, including the notes on serial cable wiring.
When soldering is complete, all traces should be carefully checked with a multimeter before powering the board. The traces on the PCBs are very fine and run close to pins of other components.
WARNING: In our test build there was a bridge between the trace leading from P20 of U10 and the pad on the underside of the board for pin 1 of U13 (square pad) where the trace leading from P20 of U10 comes very close to P1 of U13. This was fixed by by carefully scraping with a knife between the traces where they touched. A similar issue was found between P20 and P23 of U10. The board should initially be powered using a current-limiting supply in case of any remaining shorts between components, and only after all connections have been checked twice with a multimeter.
International Delivery:
Package is ~250g and measures ~220x210x70mm
Shipping will be via Australia Post international parcel services (TRACKED).
Shipping cost will be added after you make your selection below.
Shipping cost will be added after you make your selection:
PayPal:
Australian Delivery ONLY:
Shipping will be via Australia Post parcel post (TRACKED).
Shipping cost will be added after you make your selection below.
Australian orders include 10% GST.
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