This is for the purchase of the BARE BOARD ONLY. The completed project is only shown for reference. This is for the TIN version, the GOLD version listing is here

New for version 2.0b The floating ground on the DB9 is correct in version 2.0b. See user manual for additional details

New for version 2.0 (see video) are two universal EPROM sockets provide 2x2732, 2x2764, 2x27128, or 1x27256 EPROMs, one socketed on the board and the second in a ZIF for easy swap. Note that the memory map has changed from v1.x of the CPU board so programs will need to be re assembled/compiled. The v2.x memory map is on the schematic and user's manual on the project website.

Notes:

• This is a first run of a new version. It has been tested but there is still the opportunity for unforeseen surprises.
• I have discovered that the SID line is not connected to the backplane finger in version 2.o. This has been corrected in v2.0a. Easy patch but a mistake nonetheless. This does not effect operation, but the SID LED on the bus monitor will not work unless this is patched.
• If tin boards are ordered, (not gold plated) the leading edge of the fingers do not have a bevel and needs to be broken to prevent damage to the backplane. See video

The SBC-85 CPU board is a 100mm x 100mm 2-layer with a 120 pin edge connector (mechanically PCI). The serial SID and SOD lines, via a max232, offer a RS232 serial port for communication with a resident monitor or whatever you may decide to put in firmware. The 120 expansion bus includes power, all of the 8085 status and system signals, latched address bus, and many more unused terminals for future or other board-to-board signals.

RAM is provided by a 64-kBit 6264 and an additional 2kbit in the 8155. In addition to the additional RAM, the 8155 provides an onboard timer and 22 pins of I/O.

Power is provided by an external regulated 5V power supply through either the barrel connector or the backplane.

INTERNATIONAL SALES: We would really, really encourage anyone out side of the US to submit an order directly to the PCB house. we can walk you through every step of the way. In the end, it will be far cheaper to get 5 pieces from the PCB manufacturer than to ship from the US. As backwards as it sounds, the USPS subsidizes shipping into the country but we pay a premium to get things out of the country. We have limited international sales to our ebay store where we use the ebay international shipping programs. Please search there for SBC-85 computer and the items should show up.

Other boards including the backplane, cassette interface, prototyping board, bus monitor are also available. More information is available at the project website

8534.00.0040