The Original SB180, 6MHz
The SB180 is a single board computer designed around the
Hitachi HD64180 Processor
Steve Ciarcia, of Circuit Cellar fame, designed the SB180. The design appeared in two
consecutive issues of Byte Magazine: September and October 1985.
The SB180 has the following features:
* 256k-byte 150nsec DRAM, with one hardware wait-state inserted for DRAM access.
This was typically divided into a 64k TPA for CP/M - Z-system, and a 192k RAM disk.
* 8k EPROM, with boot code and monitor. Designed to handle 16k and 32k EPROMs also.
* two RS-232 serial ports, 300 to 19200 baud. One is the console (terminal) port, the
other could be used for a modem, etc.
* floppy disk controller, single/double density, which could handle up to four drives (3.5, 5.25,
or 8 inch, in any combination).
* Centronics parallel printer port.
* requires only +5 and +12 VDC. The +12 VDC was used only for the serial port drivers. An
onboard DC inverter provided -12 VDC for the serial port drivers.
* board size is 4 by 7.5 inches.
Click on picture for a larger image.