The SYM-2 was an evolution of the SYM-1.
From the press release:
Synertek has introduced the SYM-2, which offers a choice of microprocessor (6502, 6809 or 6802). The SYM-2 is software compatible with the SYM-1 and adds some hardware features: on-board power supply , eight toggle switches for input, eight LEDs to display output in binary and cassette interface jacks. Hardware compatibility between the two SYMs ensure that RAM and disk interface devices that work with one will work with the other. Designed for learning computer hardware fundamentals, the SYM-2 sells for $249 from Synertek Inc.
In fact the SYM-2 is a simplified SYM-1. Maximum RAM is 1K on board, only two ROM sockets, one VIA. And much less jumpers! The KIM-1 compatible edge connectors are gone.
But the use of the 6809 CPU was a nice possibility
Photos by Paul Schroeter.
Sources of SYM-1 and SYM-2 Monitor ROMs
Many years ago Paul R.Santa-Maria (who sadly left us in 2012) gave me the listing of the source of the Monitor ROM in the SYM-1 1.1
Delivered as a listing, with the comments from the listing in the SYM-1 Reference manual and formatted close to the printed listing.
This is the heading of the listing:
SYM-1 SUPERMON AND AUDIO CASSETTE INTERFACE SOURCES
COMBINED AND CONVERTED TO TELEMARK ASSEMBLER (TASM) V3.1
0002 0000 ;
0003 0000 ;*****
0004 0000 ;***** COPYRIGHT 1979 SYNERTEK SYSTEMS CORPORATION
0005 0000 ;***** VERSION 2 4/13/79 “SY1.1”
Since the ROM of the SYM-1 1.0, 1.1 and the ROM of the SYM-2 are available:
- Converted the listing back to source format (TASM32, standard MOS format).
- Created separate source for the SYM-1 1.0 ROM, the SYM-1 1.1 ROM (the original listing) and the SYM-2 2.0 ROM.
- Typed in the audio cassette interface sources from the 1.0 reference manual.
- Changed the SYM-2 source to the different hardware (a 6532 at AC00 instead of a VIA) and other (minor) changes.
- Binary output compared to the original ROM dumps as proof the sources match the dumps.
In this archive sources of 1.0, 1.1, 2.0 listings, ROM as binary output.