Arnewsh SBC08K Projects and References

The SBC08K is a Motorola 68008 based single board computer designed by Arnewsh in 1986. In addition to the 68008 it contains a 68230 PI/T and 68681 DUART, giving it an easy to work with CPU and a plethora of I/O options. However, the board’s best feature was its price: RIT’s Computer Engineering Department gave a wastebasket discount on these boards in mid-2010, and since then they’ve become one of my favorite tutoring accessories. Provided below are a select group of reference materials, code, and projects for the SBC08K. Unless otherwise noted, the software and hardware will operate on a standard 32KB-equipped board and may be loaded using "LOAD_BIN." Code has been written to compile under SNASM68K and to generate LOAD_BIN headers, but may easily be modified for other assemblers.

Reference Materials:
SBC08K User's Manual
TUTOR 1.3 User's Manual for SBC08K
68000 Programmer's Reference Manual
MC68230 PI/T User's Manual
MC68681 DUART User's Manual

Software and Tools:
Arnewsh TUTOR 1.31- Arnewsh's modified version of Motorola's original 16KB "TUTOR" firmware. Should be installed in U4 ($E0000).
Arnewsh TUTOR 1.31 + LOAD_BIN- The TUTOR firmware ($E0000-$E3FFF) with LOAD_BIN ($E4000+) appended.
PAL16V8 Memory Mapper- Provides the standard TUTOR memory map. (PDS Source), (JEDEC)

SBC08K Equates- The equates for the board peripherals, IRQ Vectors, etc.
LOAD_BIN- Do away with TUTOR's S-Records, and use this binary loader instead. Designed to be programmed to an EPROM located at $18000 (call with "G $18000").
Also available appended to the end of the TUTOR firmware ($E4000) above. (ASM Source), (BIN, $18000)




LED-DAC Expansion Board (J21)

The LED-DAC board is a simple J21 expansion board providing the user with sixteen (eight red and eight yellow) LEDs along with a DAC0808 which may be controlled through the 68230 PI/T.
The eight red LEDs are connected to Port B of the PI/T, while the yellow LEDs and DAC are both connected to Port A.

Board Schematic

Example Software:
LEDDAC_C- Displays the current and previous ASCII character code on the LED arrays. (ASM Source), (BIN, $1000)
LEDDAC_A- A simple animation using both LED arrays updated with a 16Hz IRQ. (ASM Source), (BIN, $1000), (Video)
LEDDAC_S- 8KHz sample playback on the DAC0800. You must provide your own 8KHz, 8-Bit mono, unsigned sample. (ASM Source), {No BIN}, (Video)