SYM-1 Monitor and RAE

SYM-1 monitor

The SYM-1 monitor, Supermon, is described in the Reference manual
Written by Manny Lomas, of TIM-1 and RAP fame.

Two versions of the monitor were shipped, Version 1.0 and Version 1.1.
Version SY1.1, the second release of Supermon, is described in a separate manual.

Appendix M describing the version 1.1 Monitor enhancements and listing.

The ROM contains Supermon, the machine monitor, the audio cassette functions and the boot ROM function (vectors asn such aare cleverly loaded into RAM by some hardware tricks with protected RAM at upper memory.


Written by Manny Lomas, of TIM-1 and RAP fame. RAE is an optional ROM.
An assembler and editor in 8K.

RAE-1 Reference manual. Only one version is known.

ROM binaries

RAE Reference cards, click for larger view.

9600 baud patch, Disassembler for RAE, RAE to ASCII converter, Cross referencer, all in RAE source format

SYM-1 XRAY Extended RAE, manual and listing

SYM-1 XRAY Extended RAE, manual and listing

SYM-1 MOD-68 MOD-69

MOD-68, MOD-69, SYM-1/68, SYM-1/69

The MOD-69 and MOD-68 replace the 6502 with a Motorola 6809 or 6802 CPU on an adaptor board and the Monitor is replaced  with a new ROM with a new Supermon.

Scans from Synertek Products Guide.

There were also SYM-1’s available with the Motorola processor 6802 : SYM-1/68 and 6809: SYM-1/69.

SYM-1/69 SYM-1 supplement manual
ROM of MOD 69, 2-9002-129 MOD 69 Hi 2-9002-12 MOD 69 Lo
PROM 82S129 of MOD 69 (2103 marked IC in photos below


SYM-1 Manuals and Ref cards

SYM-1 manuals

Reference manual second printing August 1978
Reference manual third printing June 1979
Technical Notes, April 1979
Circuit Diagram SYM-1
SYM-1 Theory of Operation Hardware by Robert Peck
SYM-1 Theory of Operation Monitor by Robert Peck
Hardware manual
Microprocessing fundamentals,
SYM-1 Seminar workbook,
Raymond N. Bennett and John Stockdale, 12/1/79
First Book of KIM-1 for SYM-1

Reference cards


Seawell produced many KIM-1/SYM-1/SIM 65 boards. Here some advertisements frion the 6502 User notes.


Brutech BEM

A Dutch company, producer of many 6502 and more industrial hardware, BEM was the name one of their product lines.

Brutech Electronics Microsytems – B.E.M

Gebroeders Bruyn, Vinkeveen. Small company, custom made electronics and standard microprocessor boards and systems aimed at industry and hobbyist.
During my years with Radio Bulletin we often worked with Brutech, and I visisted their office/manufacturing plant in Vinkeveen several times. The BEM-bus became the standard bus for expansion at Radio Bulletin after the first BEM-1 card was connected to the KIM-1 by Dick de Boer. Brutech specialized in the beginning on the KIM-1/VIM/SYM-1 expansion cards, later on they made their own CPU cards and besides the 6502 CPUs like the 6809 were available.

BEM-1 card, as used in the KIM memory expansion article November 1977
The BEM bus
Brutech sold the VIM-1 and SYM-1, with their cards as expansions.
Review in Radio Bulletin November 1978
Brutech sold also the PC100, the Siemens OEM version of the AIM 65. Again the expansions could be used, same bus.
Review in Radio Bulletin August 1980
The AIM 65 and KTM-2 packaged as the Samson system,. the BEM-4 memory card, the SYMP universal programmer.
Review in Radio Bulletin November 1980
BEM RTC1 card, advert in the RB CB Special 1980
BEM-Impact 1000, a BEM-bus based development system, review in Radio Bulletin Oktober 1980
BEM Eurocard system, article by C.J. Bruyn, on the BEM bus, BEM-MON-1 (a TIM 6530 004 system!) and other cards

Micro-gebeuren november 1977, BEM-1, other BEM cards
Micro-gebeuren April 1980, BEM-PSIO-1 USART card, BEM-AD3, BEM-AD4
Micro-gebeuren Mei 1980, BEM-6 16/32K EPROM card
B.E.M. SBC4D(2) 6809 based CPU card on the BEM bus

MAiS, a system for airtraffic control, developed around the BEM SBCD4 and a custom card.

As editors of the magazine Radio Bulletin we had many conversations with them and wrote articles about their products.

For the KIM-1 and SYM-1 they had many products, some based on the so called BEM bus (DIN 31 pin connector), some as addons to the 22/44 edge connector of the KIM-1.
I stilll own this 4K RAM card:

BEM SBC4 in MAIS box
An example of a 6809 CPU board in a custom industrial application. Bought front eh HCC Forth UG in 2004.


HDE card cage, floppy drive

Hudson Digital Electronics Inc

Known by advertisments in the KIM-1/User Notes.


Books for the 6502: KIM-1 and more

KIM-1, AIM-65, SYM-1 and other 6502/65C02/65C816 related books.

A mix of English, German and Dutch books.

On my bookshelf I have quite a collection of books on the 6502 family.

Note that manuals and books that come with systems are shown on the pages of the corresponding system!

1984 Rockwell Data Book
6502 Software Gourmet Guide and Cookbook
6502 Users Manual
AIM 65 Laboratory Manual And Study Guide
Anwendunsgbeispiele fûr den Microprozessor 6502
Microprocessor_Fundamentals KIM-1
Best of Micro Volume 1 1978
Best of Micro Volume 2 1979
Compute’s Machine Language for Beginners
Compute’s The Second Book of Machine Language
Programming a Microcomputer 6502
Programmieren von Mikrocomputern CPU 6502 (Skriptum)
How to Build a Microcomputer .. and really Understand It!
Mikrocomputer ohne Ballast
Micro Principles KIM-1 user guide chapter 8
Digitaalschakelen met de KIM-1
6502 Assembly Language Programming
6502 Programmieren in ASSEMBLER
Microcomputer Experimentation with the MOS Technology KIM-1
6502 Machinetaal Subroutines
6502 Assembly Language Subroutines
Microcomputer experimentation with the AIM 65
Machine Language Programming Cookbook part 1
Machine Code for Beginners
microcomputer systems principles featuring the 6502 KIM
Beyond Games: System Software for your 6502 Personal Computer
Assembly Language Programming
Using 6502 Assembly Language
6502 Machine Code for Humans
Programming the 65816 including the 6502, 65C02 and the 65802
Programming the 65816 including the 6502, 65C02 and the 65802
Forth Programming
Programming the 65816
Programming and Interfacing the 6502 with Experiments
Synertek 1981-1982 Data Catalog
Synertek DataBook 1983
Third Book of OSI
TSC 6502 Games Package 1
TV Typewrite Cookbook
Zaks 6502 Anwendungen
6502 Games
6502 Applications
Advanced 6502 Programming
Fortgeschrittene 6502 Programmierung
Programmierung des 6502
Programming the 6502
6502 Applications book
Programmeren van de 6502
Microprocessor Interfacing Techniques
Microprocessor Concepts and Applications
Publisher: Lab-Volt
6502 Assembler-Kurs für Beginner
6502 Machine Code For Beginners
A low-lvel language for use on the MOS 6502 Microcomputer
6502 Microcomputer Programmierung
Programmieren in Maschinensprache 6502
The Giant Handbook of Computer Projects
First Book of KIM
The First Book of KIM-1 in PDF format
The First Book of KIM-1, part in text format
The First Book of KIM-1 in HTML format
Sources of The First Book of KIM-1 in source and papertape format, Jeff Tranter
First Book of KIM-1 for SYM-1
Rockwell Produktübersicht in deutsch
Rockwell Microelectronic Data Devices Catalog 1979
1981 Rockwell Electronic Devices Division Data Book
1984 Rockwell Data Book
1985 Rockwell Data Book
1987 Rockwell Controller Products Databook

Corsham boards

AIM 65/SYM-1/KIM_1 expansion boards are still available: the excellent Corsham Technologies boards offer RAM/EPROM/I/O with modern SRAM (low power, low IC count) in kit or assembled format. Here are the boards offered, I use them on my MOS KIM Reproduction KIM and SYM-1 and AIM 65.

First the current available boards, later the older boards

KIM-1 RAM/ROM 60K board

This is a combination RAM and EPROM board with a fair amount of flexibility for adding more functionality to your KIM-1!

Fills in the KIM’s missing RAM from $0400 to $13FF, giving you 5K from $0000 to $13FF.
Has RAM from $2000 to $FFF7, selectable in 8K segments.
The top 8K ($E000 to $FFFF) can optionally be replaced with 8K of EPROM on the board (27C64 EPROM).
Includes the xKIM extended KIM-1 monitor by default.
The xKIM monitor has commands to load hex files, dump and edit memory, a memory test, plus commands to access SD card features from our SD Card System.
The extended monitor has vectors to command functions so programs written for it won’t break when new versions are introduced.
This board can be added to any KIM-1 system, but the easiest way to add it is with our I/O Board. This board comes with a ribbon cable that plugs right into the I/O Board with no mess. By default the DIP switches are set so your KIM will have 5K of RAM from $0000 to $13FF and from $2000 to $DFFF. The extended monitor is from $E000 to $FFFF.

KIM 60K RAM ROM Manual
Schematic KIM 60K RAM ROM board
Memory test program

KIM-1 I/O board

KIM I/O manual Rev C
Schematic KIM I/O board

The KIM-1 Application connector has a lot of useful signals on it and our expansion board makes them easily usable, as well as providing an RS-232 interface to the KIM’s serial port. The KIM has a 20 ma loop interface because that was the standard used by mechanical teletypes commonly used as terminals in the early days of the microcomputer revolution. Now we all have RS-232 ports on our computers and our I/O board allows a modern computer to connect to the KIM.
The expander plugs into the KIM’s Application connector. The lower left hand side of the board has a DB-9 connector that mates with a standard cable to a PC serial port.
Just above the serial connector are two standard 1/8″ inch audio connectors for a tape player; some people still like saving data to tape, just like in the old days. If both cables are out then the audio in/out lines are connected; this is perfect for running PLL adjustment programs. There is a jumper to select whether to use the audio high or low connections.
Above the audio connectors is the power connector with connections for +5, +12 (only needed if the cassette interface is used) and Ground. A filter capacitor is present to keep the voltages smoothed out.
Two of the best additions to this board are the POWER LED and KBD/TTY switch. A few people, myself included, have almost pulled board or made other changes while power was on. The handy LED provides an indication that 5 volts is present.
If you’re switching back and forth between the normal KIM KBD operation and using an external TTY device, there is now a small switch located on the board that is clearly labeled as to which position is for KBD and which is TTY.
There are various connectors and a set of switches provided for feeding the K1-K4 lines to an external memory board, such as our 4K or 60K memory boards. Each K* signal is individually selected, so if you have peripherals in any of the K1-K4 banks, you can disable any of those signals from going to the external board.
All of the remaining I/O lines are brought to a header for expansion.

KIM-1 6530 Replacement board

A very common problem with maintaining 40 year old computer systems is that some of the parts have not been made for many decades, such as the two 6530 chips on the KIM-1. Each contains several timers, 64 bytes of RAM, multiple parallel I/O ports and 1K of mask programmed ROM containing the KIM-1 monitor program. To make things even more complicated, each 6530 is mask programmed with a number of configuration options such as which interface pins and address lines select which internal devices.

Many people, Bob included, have at least one KIM-1 in their collections with a non-functioning 6530. Depending on what failed, the KIM might be quite usable, completely unusable, or someplace in between. For these people, there was little chance of ever fixing the problem because the two 6530s in the KIM are unavailable anywhere… not even on eBay! In an effort to fix his own KIM, Bob borrowed work of other people and developed a small board that can replace either 6530 on a KIM-1.
Basically this emulates the functionality of the non-functioning 6530 by using the I/O ports, RAM, and timers from the 6532 chip, and then having an external EEPROM hold the code that was in the ROM of the original chip.

The board replaced U2 (6530-002) on Bob’s KIM and produces a fully functional system again. This is a prototype board (strange board color) but is identical to the production version otherwise.

For full documentation, schematics, design files, Gerbers, EAGLE CAD files and other technical data please also see Bob’s development notes.

The assembled version is the quickest way, and the easiest. Just set the three jumpers to either U2 or U3 to indicate which chip you’re replacing, remove the old 6530, then plug in this board. Bob strongly suggest saving the original 6530 in case you ever decide to sell your KIM to a museum as a static display.

KIM-1 6530 Replacement board manual
KIM 6530 technical notes
Schematic KIM-1 6530 replacement
kim-1 6530 design: gerbers, eagle, KIM ROM

AIM 65/SYM-1 60K RAM

Basic features of the board:

  • Can be used on either a SYM or an AIM.
  • Memory selectable on 4K boundaries covering the entire 64K address space. Not all blocks can be RAM, as the SYM-1 already has up to 4K of RAM on-board, there are multiple ROM sockets, and I/O.
  • The top $80 bytes are not available; that area is reserved by the SYM-1.
  • Can allow space for BASIC or other software in ROM. My system has an 8K BASIC ROM so I did not place RAM at C000-DFFF.

The Rev 2 boards have an additional chip which works around a bug in early AIM-65 boards. We know the problem was in rev 1 and rev 0 AIM boards, and it was definitely fixed on rev 4 boards, but I don’t know exactly which revision fixed the problem. Basically the RAM_R/W signal (pin Z on the Expansion connector) had the inverted Phase 2 clock NAND’ed with R/W. The SYM and AIM were both supposed to follow the KIM standard, but Rockwell got this one signal wrong.
Rev 2 boards have replaced the jumpers with a pair of 8 position DIP switches; those are easier to set and there are no jumpers to get lost ??
When running the ROM BASIC, this is what gets displayed:




Here RAM is configured from 1000-7FFF, B000-BFFF, and F000-FF7F. That gives a lot of room to squeeze in useful add-ons to the monitor.

SYM-1 AIM 65 60K RAM manual
Schematic V1
Schematic V2

22/44 pin Extender Board

One side has a 22/44 connector ready to plug into your KIM or any other computer with 22/44 edge connections on .156″ centers. On the other side are the same pins for you to plug another board into.

In the middle is the cool stuff. All pins brought to a .1″ center header, and each is labeled so you won’t forget that some letters aren’t used ??

There are a couple of good uses for this extender. First, you can easily probe any signal between the KIM and add-on board. Nice. The other big plus is that it saves wear and tear on the edge connectors of the KIMs in our lab. They are almost 40 years old, so we try to be gentle on them.

An older version in use in our workshop…

KIM-1 4k Memory board

Not available anymore. A very simple board to add 4K RAM to lower address space ($0400-$13FF

Manual KIM-1 4K RAM board
Schematic 4k RAM Board

KIM-1 60K RAM board

Not available anymore. A forerunner of the 60K RAM ROM.


KIM 60K RAM Manual

Schematic 60K RAM board


Micro Technology Unlimited K-1012 K-1008

Micro Technology Unlimited produced a lot of hardware for the KIM-1, SYM-1, AIM 65 and more. The company still exists, now sells music software.
Started by Hal Chamberlin (of fame woith his articles in Byte about musci generation with computers), it sold a lot of music related KIM-1/SYM-1/AIM 65 hardware and software and later standalone MTU130 6502 based computer. The company is still in business.

MTU Fall 1980 6502 Peripherals and Software catalog
MACASM User Manual (MTU130)
K-1008 by MTU, video display 320×200, 8K memory manual 
Use of the K-1008 for grey scale display, app note #2 
K-1020 Prototyping board by MTU
K-1012 PROM/IO board by MTU, 2 PIA, EPROM, 1 ACIA 2708/2716 programmer manual
K-1009-IC AIM 65 Printer Enhancement Package

K-1008 Visible Memory

K-1008 Visible Memory

K-1012 PROM Expansion Board

K-1012 PROM Expansion Board

K-1016 Memory Expansion Board

K-1016 Memory Expansion Board

K-1020 Prototype board

K-1032 Expansion Board

K-1032 Expansion Board


KIMSI S100 motherboard/interface

KIMSI, Motherboard KIM-1 to S-100
Byte 1978 08 Advertisement
KIM-1 KIMSI, KIM-4 Enclosure
8K Visible Memory
KIMSI announcement