Overview

From Spare Time Gizmos' Wiki

Comparison of SBC6120 Models

SBC6120	Model 2	Model RC
Front Panel	Computer and front panel are separate PCBs Uses custom manufactured faceplate Silkscreened in five colors, laser cut and laminated Uses 20 paddle switches w/colored plastic handles Recessed LEDs with windows and a shadow mask Looks like a real PDP-8/E	All components are integrated onto a single PCB You make your own faceplate Laser printer graphics and sheets of clear acrylic Uses 20 miniature toggle switches w/metal handles “Poke thru the panel” LEDs Looks like an Altair “Power ON” LED
	Both front panels are functionally identical with 15 address LEDs, 12 data LEDs, RUN LED and POWER LED (-RC only) 12 data switches and 8 function switches (BOOT, LA, LXA, CLEAR, CONT, EXAM, HALT, DEP) display select rotary switch
Memory	32K word EPROM for BTS6120 firmware 64K word RAM 32K “main” memory for OS/8 and user programs 32K control panel memory Optional RAM disk daughter card	32K word EPROM for BTS6120 firmware 512K word RAM, optional expansion to 1024K words 32K “main” memory for OS/8 and user programs 32K control panel memory 448K (960K optional) word built in RAM disk for OS/8 RAM is non-volatile with Li coin cell backup battery
Peripherals	KL8E compatible console serial port IDE/ATA interface built in Optional RAM disk daughter card Optional IOB6120 card adds 3x serial ports Centronics printer port VGA and PS/2 keyboard ports real time clock calendar CompactFlash card additional RAM disk. 50 pin expansion bus Build your own peripherals!	KL8E compatible console serial port No IDE/ATA interface RAM disk built in Optional VT6 daughter card No expansion bus
Other	On board switching power supply (on FP6120) External 9-12V unregulated supply required POST LEDs Reset push button	No onboard power supply External regulated 5V supply required POST codes displayed on data LEDs Reset on power on only