I bought several products from RetroSpy.

• PAL-1 Motherboard Expansion Kit
• KIM-1 RAM/ROM Board
• MOS 6530 Replacement for the KIM-1 SBC
• Bus extender

Other interesting KIM-1/AIM 65/SYM- related boards on the Retrospy shop:
AIM 65 I/O board
SYM-1 I/O board
SYM-1 SymDos I/O board
SYM-1/AIM-65 RAM/ROM board
KIM-1 I/O board
2532 to 2764 EPROM adapter
SD Card Storage System (like the Corsham one)

I should have bought he KIM I/O card also, for the 1541 connector, next time!

My first encounter with Eduardo Casino was this topic on the German forum64.de forum in early 2023

If you do not read German: Eduardo, from Madrid, Spain!, announces his project to replicate a KIM-1 Rev D with the exact layout and look and feel as the original, using hires photos, Inkscape and Kicad.

This is not the first KIM-1 replica, as you can see here. What makes this replica special is that it is an exact PCB
replica. With curved lines! Other replicas may have the same dimensions and look and feel but use the straight modern PCB lines design.
He set a high standard and het continues to amaze us with hardware designs and software around the KIM-1. read all about on the follwing pages:

• KIM-1 rev D PCB redesign Eduardo Casino
• Dual 6532 adapter board
• KIM-1 keypad replacement

MTU replicas and additions

• MTU K-1008 Visable Memory Replica and MT motherboard

K-1008 Visable Memory Replica by Eduardo Casino

K-1013 Floppy Disk Controller replica

KIM-1 Motherboard for MTU Cards
KIM-1 RAM/ROM Expansion Board for the MTU Backplane
KIM-1 Programmable Memory Board for the MTU Backplane

CP/M-65

Version for the K-1013
KIM-1/PAL-1 version

KIM-1 Software

K-1008
XKIM
1541 OS

RAE was the name by Synertek for MAE, as ROMs for the SYM-1 which could be installed to add the Resident Assembler/Editor (RAE). Synertek contracted Eastern House Software to port their Macro Assembler/Editor (MAE) into an 8 KB ROM. AS you can see in the reconstructed source, the adaptations were not much more than adding the SYM-1 I/O such as character I/O and tape handling, the essence of MAE stayed as RAE. It was not that popular in the SYM-1 world, even Synertek used internally another assembler, with more MOS Technology compatible syntax.

The author of MAE and RAE, was Carl Moser. MAE was sold in various forms not only for the KIM-1 and SYM-1 but also for other 6502-based computers including Commodore, Atari, KIM, and Apple and in the Netherlands the Elektor Junior. Other forms of MAE included a cross assembler for 6800 and 8085.
Carl Moser and JR Hall were founders of Eastern House Software, the company that created several products for Atari 8-bit users, including Monkey Wrench and Monkey Wrench II, and the KISS word processor.

On topic on this site are the preserved KIM-1, SYM-1 and Elektor Junior versions. I have binaries, manuals and (reconstructed) sources for these versions for download.

Note that the manuals for the SYM-1 RAE are well written, and a good addition for the manuals of MAE.

On this page:

• KIM-1 Macro Assembler Editor
• Elektor Junior ASSM/TED
• SYM-1 RAE

• Catalogs and flyers Eastern House Software
• PC commandline tools to manipulate MAE/RAE files

Catalogs and flyers Eastern House Software

		Eastern House Software Catalog
		Eastern House Software Dealer Brochure
		EHS catalog 1985
		EHS catalog
		EHS flyer
		EHS Gazette 1981-03

PC commandline tools to manipulate MAE/RAE files

To get text into and out of the ASSM/TED program on the 6502 computer to the PC world,one can use several methods.
Written in Freepascal. Sources included, can be compiled in Linux etc.

The first method is using a terminal emulator and upload a text file or catch the output of the ASSM/TED program.
That gives some problems, mostly related to missing line numbers, or too much blanks.

Strip Blanks
The output of ASS/TED to the screen contains many blanks. When you want to uplaod the captured output, those blanks have to go

D:\myfiles\MAE\PC tools>StripblanksMoser.exe
V1.0 Strip blanks from captured ASSM/TED Moser source file
V1.0 Hans Otten, 2024
Syntax: StripBlanksMoser <sourcefile with blanks> <output source file to upload 
to ASSM/TED> [Y]
Y to overwrite outputfile without question asked

Add numbers
When you have a MAE/RAE source file without numbers, you can add those with this utility, increment of 10.

D:\myfiles\MAE\PC tools>AddNumbersMoser.exe
V1.0 Add numbers 0001-9999 to source file to make a ASSM/TED Moser source file
V1.0 Hans Otten, 2024
Add numbers 0001-9999 to ASSM/TED Moser source
AddnumersMoser <sourcefile without numbers> <output source file with numbers> [Y]
Y to overwrite outputfile without question asked

The other method is to dump or upload the text buffer as memory binary dumps.
Text is stored in memory as:
..
e.g.
the text
10 test
is stored as:
00 10 20 74 65 73 F3

RAE to TXT
Converts a binary MAE/RAE file to an ASCII text file without line numbers and normal line end

D:\myfiles\MAE\PC tools>RAEtoTXT.exe
V1.0 Convert a  ASSM/TED Moser RAE memory dump to text file
V1.0 Hans Otten, 2024
RAEtoTXT sourcefile memorydump output text file  [Y]
Y to overwrite outputfile without question asked

TXT to RAE
Converts a text file to binary RAE format, with line numbers.

D:\myfiles\MAE\PC tools>TXTtoRAE.exe
V1.0 Convert a  text file to ASSM/TED Moser RAE memory dump
V1.0 Hans Otten, 2024
TXTtoRAE <textfile > <output memorydump file  [Y]
Y to overwrite outputfile without question asked

How to dump or upload the the MAE/RAE text buffer

Dump

Start ASS/TED and add some lines

C 1979 BY C. MOSER


4163-53FC  5400-5EFC  5F00
4163  5400

10 test
20 lege regel
set

4163-53FC  5400-5EFC  5F00
4176  5400

Current (4176 in example above is to be stored at D3 (low), D4 (high))

BR to the KIM monitor and save 4163 to 4176 to a file, remember the end address, add that to the filename!
Upload

– Start ASSM/TED and BR to monitor
– Load the text file, place the end address in D3 (low), D4 (high)
– Enter ASSM/TED via the warm start at 2003 (KIM-1) or B003 (SYM-1)

Luckily we can build a KIM-1 clone that is either cheap and compatible, like the PAL-1, or a bit more authentic as the various KIM-1 boards.
Anyway, a clone has the KIM ROMs, and in E(E)PROM, to make it a KIM-1 clone. Altering is not done, you loose that unique spartan user interface!

The Apple 1 has also a monitor program, often called Wozmon to honor the genius of Steve Wozniak.

And you can combine both user interfaces on a not expanded KIM-1 clone!
I also included the Wozmon as a Setting in the KIM-1 Simulator.

Read more here!

The Apple 1 monitor (Wozmon) to be included in the empty space in the KIM-1 tape ROM

The Apple 1 and the KIM-1 are some of the earliest 6502 systems made.
Both are desirable, Apple 1’s sell for lots of $$$ and KIM-1s are getting more expensive.

Luckily we can build a KIM-1 clone that is either cheap and compatible, like the PAL-1, or a bit more authentic as the various KIM-1 boards.
Anyway, a clone has the KIM ROMs, in an E(E)PROM, to make it a KIM-1 clone. Altering is not done, you loose that unique spartan user interface!

The Apple 1 has also a monitor program, often called Wozmon to honor the genius of Steve Wozniak.
And you can combine both user interfaces on a not expanded KIM-1 clone!
Ronny Ribeiro, a user of a PAL-1, saw that the KIM tape ROM has quite some unused space. In a real KIM-1 that is wasted, you cannot program the ROM.
In a clone you can. He saw that that free space is large enough to hold the Wozmon, adapted a bit for the KIM-1 TTY I/O.
He offers a ROM image for a clone, with the Wozmon built in at 1AA0. And added a command to go back to the KIM-1 monitor.
He also used the ROM with the ‘KIM’ prompt in his system with ‘PAL’.

I moved wozmon in the original KIM ROMs in 2K image with Wozmon in the tape ROM empty space.

Start Wozmom at $1AA0, used buffer at $0300

Based upon the ideas and work of Ronny Ribeiro.
Source included. Standard 6502 assembler, I used TASM32

The KIM-1 Simulator is used to test this. And this Wozmon is now available in Settings!

Here I offer you that ROM. I reconstructed the source and added the result to the KIM-1 ROM image. WIthout the KIM prompt change!
In the archive you find source etc of the Wozmon for KIM, the binary ROM image to load in the KIM clone rom, the Wozmon for KIM-1 source and a small userguide by San Bergmans.

Tiny Basic interpreter Copyright 1976 Itty Bitty Computers, used by permission

Tiny Basic on the Superjolt

On this page information how to run Tiny Basic, by Tom Pittman, for the KIM-1 or a TIM (RRIOT 6530-004) based machine, like Jolt and Superjolt, with 4K RAM at least extra.
Any 6502 machine with character I/O can run Tiny Basic, source is available with just a few changes to be made to I/O, memory layout and breaktest. Note that most of the zeropage is used by Tiny Basic!

All tests and binary file manipulation with Tiny Basic have been done with my KIM-1 and TIM Superjolt simulators.
File conversion between binary and papertape and such is done with the Convert Hex 8 bit formats utility.

On this page you find:

• My work with Tiny Basic
• Tiny Basic manuals
• Downloads binaries, sources for KIM-1 and Jolt/Superjolt/TIM
• Tiny Basic programs
• Magazine articles
• IL Basic Interpreter
• Other sources of information, systems with Tiny Basic
• KIM Kenner article 1980



My work with Tiny Basic

Here I present you with all I own, know and have reconstructed about the 6502 (and 6800) ports of Tiny Basic by Tom Pittman.

1979 I bought a Tiny Basic package for my KIM-1 from the Dutch distributor Ing Bureau Koopmans for Hfl. 25,- and the package came as a number of documents (User manuals, Getting the most out of Tiny Basic, and the Experimenters kit) and a cassette with two versions of Tiny Basic program in KIM-1 audio format:
– a low version of the program from 0200 to $0AFF, start address $0200
– a high version from $2000 to $28FF, startaddress $2000
– a Break test routine placed in the lower stack page, $0100-$0114

In 1979 I build a videoterminal (24×32 uppercase monochrome!) and the KIM-1 had 4K memory added in lower memory. So I could use Tiny Basic!

In 1980 I published, in the Dutch KIM Computer Club Magazine KIM Kenner, an article about Tiny Basic, with some patches and tips.

In 2004 I scanned the manuals and dumped the audio cassette wich contained the only remaining Tiny Basic files on cassette. Not the lost original but patched versions as described in the KIM Kenner article I wrote in 1980, reproduced below. I tested those ‘raw’ dumps on the MicroKIM when it appeared as first KIM Clone and it ran more or less. A teletype with papertape punch and reader is not equal to a modern videoterminal.

In the years following more KIM Clones appeared such a the Cosham KIM Clone and the PAL-1. And Tom Pittman published some of the material. Other users used my and Tom’s material to let Tiny Basic run on their KIM clone machines. Also sources based on disassembly were constructed.

In 2021 the KIM-1 Simulator was born, that enabled me to dig into programs at the PC.

2023 brought me a Superjolt with Tiny Basic in ROM. And that triggered me to build a TIM Simulator. With that I could test and check the Tiny Basic ROM dump. With sources from the website of Tom Pittman I could rebuild the assembler source of Tiny Basic, and check that with the dumps I had of KIM-1 and TIM. You can see the results of that work in the Download section: Tiny Basic can be built for my two platforms on any 6502 system, be it KIM-1, TIM/Superjolt or any 6502 with character I/O. I also found that not all Tiny Basic version come with the same IL Basic interpreter, small differences between KIM-1 and TIM/Superjolt. More on the IL interpreter here

Tiny Basic manuals

The official manuals that came with my version of Tiny Basic. Cleaned up PDF versions 2023.
For a ‘tiny’ language it is very well documented! I have more expensive Basic interpreters without good documentation ..

	Tiny Basic User Manual Tiny Basic User Manual as html Tiny Basic User Manual as html Tiny Basic User Manual as text
	Getting The Most Out Of Tiny Basic Getting The Most Out Of Tiny Basic as html
	Tiny Basic Experimenters Kit Tiny Basic Experimenters Kit as html Tiny Basic Experimenters Kit as text
	First Book of TinyBasic as html
	Superjolt CP110 User Manual Also Tiny Basic, RAP userguide
	Superjolt CP110 Synertek

Downloads of binaries and sources for KIM-1 and TIM/Superjolt

From the manual on the KIM-1:
It is recommended that you save a copy of memory on tape (0100-0114 and 0200-0AFF) before going any further. Or you may prefer to save it on audio cassette. Set up the starting address for Tiny at 0200, and type “G”. Because of the awkwardness of putting memory in the 4K gap left in the KIM-1 system, an alternate version is available which executes out of 2000-28FF. For this version the Cold Start is at 2000 and other addresses are at 200x instead of 020x (cf. 010x in Appendix D).

Tiny Basic binaries and sources for the KIM-1
– raw dump contains the dump of the only remaining audio cassette files in my library.
Dumps made in 2004, lightly patched versions.
– patched original binaries: extracted from the raw dumps as described in the user manual
– original reconstructed binaries, source versions, binaries checked against the original dump with the patches removed
– patched versions , for practical use on a KIM-1 or clone with a modern video terminal emulator.
Sources and papertape included.

Tiny Basic for the TIM 6530-004 as used in the Jolt and Superjolt. All with sources and binaries..
– original ROM dumps from the Superjolt
– source and checked binaries reconstruction
– patched for more practical use, source and binaries for Superjolt and TIM
– reconstructed version of Tiny Basic for TIM as described in the User manual

Software

Tiny Basic for CC65 assembler sources
Tiny Basic programs, such as adventure
Bill O’Neill source of Tiny Basic with monitor
Tiny Basic source by Bob Applegate
Tiny Basic for the Cosmac 1802 by Robert Coward


Magazine articles

	Articles on tiny Basic ibn Dr Dobss
	Articles on tiny Basic from 6502 User notes
	Articles from the Dutch KIM user Club: KIM Kenner 23 Tiny Basic Filip van Kenhove, adapt to Elektor Junior
	1977 01 Tiny Basic a mini language for your micro
	kilobaud 1977 12 Tiny Basic
	1978 06 Tiny Basic shortcuts
	1978 10 Not so Tiny (Basic)
	Tinkering with Tiny Basic

IL interpreter

Tiny Basic is implemented like an onion:


The concept of Tiny Basic was thought of by the people behind PCC magazine, which evolved ito Dr Dobbs. A compact Basic interpreter written in the IL language, which in turn is interpreted in native code. This means lot of functionality in a small space. And porting to other computers means only having to rewrite the quite simple IL interpreter.

Tiny Basic by tom Pittman is such a ported Tiny Basic. For 1802, 6502 and 6800 CPU systems. Note that there are small differences between versions of the IL code. The code for TIM is different for example of the KIM-1 versions.

	Revised articles from PCC about Tiny Basic
	Wikipedia article about Tiny Basic Good explanation and historical overview
	Tiny Basic Experimenters Kit Contains a thorough description of IL as used in Tom Pittmans Tiny Basic, the IL Basic interpreter code, an IL assembler Tiny Basic Experimenters Kit as html Tiny Basic Experimenters Kit as text
	IL interpreter source collection 1802 6502 original
	Tiny Basic IL by Bob Applegate
	Tiny Basic IB IL interpreter source
	IL Interpreter source commented

Other sources of information on Tiny Basic

Information on the Itty Bitty Computers Tiny Basic for the Cosmac here, by Herb Johnson.
Tiny Basic interpreters 6502, 1802, 6800, IL
Tiny Basic for the Cosmac 1802 source, by Robert Coward
6800 source reconstructed by Jeff Trentor.
Tiny Basic for the 6800 hex dumps and source reconstruction
The dialects of Tiny basic


English version of article ‘Tiny Basic’

H.J.C. Otten, KIM Kenner 10 March 1 1980, page 10
With improvements on the Dutch article from unpublished handwritten notes, 1980

Tiny Basic

Tiny Basic deserves more appreciation as programming language than the low price makes us wonder.
(Note 2023; All software for the KIM-1 is free nowadays!)
The following article some advantages and disadvantages wil be described followed by some tips for improvements and ease of use.

Advantages of Tiny Basic
The program is small, 2.5K RAM besides zeropage is enough for the software.
Tiny Basic uses the KIM-1 I/O with the built-in KIM-1 character I/O routines. And of course a TTY like a videoterminal.

Tiny Basic comes in two versions. A low memory version for a KIM-1 with RAM at $0000 – $0ABF and program storage at $B000.
The high memory version starts at $2000, and program storage above.
There are no differences between the low and high memory version besides memory locations.

All I/O of Tiny Basic uses three well defined and documented subroutines, adaptation to other 650 systems requires no more adaptations.
The extensive documentation makes all clear.

Tiny Basic has two start addresses. The Cold start does a complete initialization like a clean program space. The Warm Start keeps the Basic program in memory intact.

Besides the Basic statements there is the USR function to call external 6502 code. The USR function is powerful. The first argument is the address of the 6502 routine.
The second argument, a 16 bit integer, is placed in the X (high) and Y (low) register. The third argument, an 8 bit value, in the Accumulator..
The result of the function result is the accumulator.
Tiny Basic works with 16 bit integers, signed. There are USR calls for peek and poke function.

Disadvantages of Tiny Basic
Any Basic interpreter has known disadvantages. Tiny Basic adds having only 16 bit signed integers, no floating point numbers. No string functions, no FOR .. NEXT, GOTO required, 26 variables max. And Tiny Basic is slow due to the architecture of an interpreter written in the IL interpreter.

Tip 1: Patches go improve usability on video terminals
– The “:’ used as prompt can be replaced with another character. I like ‘>’ as prompt.
– The second patch involves suppressing the video terminal unfriendly output of (un)printable characters.
– Third the backspace character $5F is better replaced with $08 for video terminals.
– The last patch increases the maximum stack depth from 40 to $20.

Patches to apply at Tiny Basic (low version 0200 and high version 2000):
Change location $0971 ($2771) to $3E (‘>’ , was ‘:’ $3A)
Change location $0211 ($2011) to $00 to suppress padding (was 84, padding on in bit 7, 4 times)
Change location $020F ($200F) to $08 (backspace) was $5F
Change location 0213 ($2013) to $20 for more stack space depth (was $04)

Tip 2: Load and save of Tiny Basic programs

There are no Load and Save statements in Tiny Basic.
But it can be done with the following procedure on the KIM-1:
Save your program
1. Halt your Tiny Basic with Reset
2. Copy the contents of $24 to EAL $17F7 (end of Tiny Basic Program storage)
3. Copy the contents of $25 to EAH $17F8
4. Fill SAL $17F5 with $00
5. Fill SAL $17F5 with $0B (0200 version) or $29 (2000 version)
6. Enter tape ID in $17F9
7. G $1800 to save to tape (or a more applicable hypertape routine)
Load a program from tape
1. Start Tiny Basic Cold start (G 0200 or G 2000)
2. Halt your Tiny Basic with Reset
3. Enter ID in $17F9
4. G $1873 to load tape to memory
5. Copy the contents of EAL $17F7 to $24(end of Tiny Basic Program storage)
6. Copy the contents of EAH $17F8 to $25
7. Start Tiny Basic with warm start G $0203 or G $2003

Since the KIM-1 monitor does not allow to use the tape load/save routines as subroutines, making this a program is not much more friendly than the manual operations.

See also:

Jolt Replica by Eduardo Casino

Eduardo Casino has created a faithful replica of the Jolt single board computer. Tested! Working! The replica design is...

MTU K-1008 Visible Memory

The MTU Visible Memory is a memory mapped video display made by MTU. Supported by the KIM-1 Simulator. See the MTU ...

TTY Serial

TTY Serial The KIM-1 Simulator comes with a 'console', a glass teletype 24x80 screen. It has a subset of ANSI/VT100 sup...

TTY Console

TTY console mode Press the TTY console switch to let the KIM simulator use a glass teletype in a console window. The st...
]]> http://retro.hansotten.nl/6502-sbc/kim-1-manuals-and-software/my-kim-1-family/ Tue, 21 Nov 2023 16:28:00 +0000 http://retro.hansotten.nl/?page_id=15273
• KIM-1 replica’s and clones
  • DIY KIM-1 Keypad
  • KIM-1 Mod a portable KIM-1 made by Voyageur
  • RC-ONE a KIM-1 clone
  • Replace both 6530s in KIM-1
  • Ruud Baltissen: Build a KIM-1
  • Wozmon in the KIM-1 clone
  • Nachbau eines KIM-1
  • Micro-KIM
  • PAL-1
  • PAL-2
  • MOS KIM-1 Reproduction
  • KIM-1 Nachbau
  • KIM-1 Replika
  • KIM Uno
• My other KIM-1 systems
• Corsham KIM Clone
• Rockwell AIM 65
• Synertek SYM-1
• MCS Alpha 1
• KIM UNO
• KIM-1 Simulator

The KIM-1 is one of the first computer systems build around the 6502 microprocessor, somewhere in 1975.
The hardware and software concepts in the KIM-1 were reused in a number of systems created later.

• Application and expansion connector
• KIM-1 monitor software in ROMs 6430-002 and 6430-003
• RRIOTs in 6530 (equivalent to 6532)
• Bitbanged serial interface
• 6 multiplexed seven segment LEDs and hex keyboard
• MOS Technology papertape format load and save
• KIM-1 audiotape format

Over the years I have collected a ‘family’ of small computers with one or more concepts of the KIM-1, as shown in the figure above.

System          Connectors KIM-1 monitor Serial  LEDS + keypad Papertape KIM-1 audio RIOT
-----------------------------------------------------------------------------------------
KIM-1                X           X         X           X          X           X        X
SYM-1                X           X         X           X                      X        X
AIM 65               X                                                        X        X
MCS Alpha 1                                X           X                      X        X
Elektor Junior                             X           X                      X        X
KIM UNO                          X                     X          X                    X 
Micro-KIM                        X         X           X          X                    X
KIM Clone                        X         X           X          X                    X
PAL-1                            X         X           X          X           X        X
MOS Reproduction     X           X         X           X          X           X        X
KIM-1 Simulator                  X         X           X          X                    X
-----------------------------------------------------------------------------------------

This is the story of me and the KIM-1.

Philips educational kits.

As a young child, at age 12, I was introduced to electronics with the Philips electronic kits. First a Pionier crystal radio. Easy to build, good instruction manual. Lots of listening pleasure!.

Two years later I bought the Philips EE8 Electronic Engineer kit. Again nice builds (the 8 stands for 8 experiments), with a good manual. Since the manual covered the expansion to the EE20 for 20 experiments, I bought the parts myself one by one at Aurora Vijzelgracht, Amsterdam.
More on the Philips electronic kits.

Radio Bulletin

In 1978 I bought my first computer, a KIM-1. It turned out to be a Rockwell rebadged Rev F Mos Technology board.

The beginning of lots of fun, learning, member of the KIM gg Club and making and publishing in the Dutch electronics magazine Radio Bulletin and the KIM Kenner.

In 2014 the big KIM-1 machine was finally taken down in parts, the following photos showed the end result as in 1985 after many years of tinkering.

The KIM-1 system ended as a real production system in 1985, mainly to write articles, all Radio Bulletin and KIM Club Magazine related work was done with this system.

My KIM-1 workplace in 1979, no video terminal, no printer, hand assembly

My workplace setup in 1982: KIM-1, dual cassette, tv monitor, H14 printer, ASCII keyboard

1984, VT100 as videoterminal, what a progress!

Then a CP/M machine took over (a Spectravideo X’Press 738) with the same VT100 as terminal.

• KIM-1
• 8K RAM  in system case
• 32K RAM in expansion case
• Two ACIA 6850 serial
• A PIA/VIA card with two 6820 PIA’s
• Parallel ASCII keyboard with home made logic circuit
• Video Display 32×32 uppercase characters on an analog TV
• Dual cassette tape system with motor control
• MDCR digtal cassette system in second expansion case
• Radio Grafisch Display in second expansion case
• Heathkit H14 matrix pinter, serial with RTS handshake via bitbanging RIOT port
• VT100 Digital Equipment Video display unit VT100
• Boot tape to load device drivers and Micro Ade (extended to 8K)
• MICRO ADE assembler/editor, used for program development and article authoring
• Microsoft Basic KB9 (not used often, nice study material!)
• Pascal-M compiler and interpreter (mainly development and experiments, not for production)

First the KIM-1, I still have it, in working condition, in my private museum. Changes still visible, a red acryl cover over the LED displays, a capacitor moved to the back to make it flat enough to fit the case I made and some supports to have it lay stable and safe on a table.

Why a KIM-1?

In 1977 I was reading in the electronics magazines about the revolution taking place: 8 bit microprocessors!
During my study I encountered Digital Equipment machines, PDP-8 in the lab, PDP-11 in the Mathematic Computer Science department, a Minc in Medical Physics group, my major.
The electronics department where I was doing an intern not only introduced to digital electronics and I helped them to introduce the Z80 to the instruments designed for laboratory experiments.
I learned assembler quickly, PDP-11 was a dream come true, the Z80 a bit of a nightmare but you could do so much with effort.

At the same time I started to write for the magazine Radio Bulletin, simple analog and digital circuits and continued to be an editor until 1987. I met Dick de Boer who was writing his famous Microprocessor articles and introduced the KIM-1 to the Dutch electronic engineers. So a KIM-1 with the very attractive 6502 was the logical choice for my first microprocessor system.

First case: memory, connectors, power supply

A KIM-1 itself was fun to learn with, but it quickly needed more; a permanent power supply, protection, easy to access connectors and interfaces for  a bus to have  more memory.
So the case seen in the next figure was built:

Power hungry, so lots of lineair power supplies with large cooling.

The first case I built from alu profiles contained the KIM-1, a backplane for 6 memory boards, a lot of power supplies (lineair, so heat was a problem!), a patch panel to access the expansion connector, cassette I/O, serial interface and various switches.

PCBs handmade, double sided!

Memory 2K RAM Card, BEM Bus Brutech Variant made by Hans Otten
Memory boards were made myself by drawing with Edding ink on the blank PCB, etching and drilling. Filled with 2102 RAM IC’s for 1K per board, it filled lower RAM of the KIM-1 $0400 – $13FF. The bus is a 31 pin DIN connector, based upon the BEM (Brutech) bus.

I bought two of this deck from Radio Service Twenthe, Den Haag, fascinating electroncis dump store!

The next thing I built was a video display unit. All TTL 74XX logic IC’s, a 2513 character generator, a AY-5-1013 character generator, an ASCII keyboard, display on TV 32×32 characters uppercase. RS232 input/output to the KIM-1.
On top of the VDU a dual cassette deck is shown. From the famous Dutch dump shop Radio Service Twente two audio cassette decks were bought, some audio amplifiers and power supply added, and a remote control circuit via a 6532 GPIO line (standard as in Micro Ade). Served me well for many years, in 2014 the decks strings were dried out and crumbled after many years of not being used.

Next was a real expansion cabinet with a long backplane for 32K memory with 8x 4K RAM card, 2114 based, Designed by me, published in Radio Bulletin and sold by Visser Assembling Electronics. BEM bus compatible.

4K SRAM card

4K SRAM card, Radio Bulletin September 1979 part 1  part 2

Production 4K RAM card

Prototype 4K RAM card, also hand drawn on the PCB!

In the expansion cabinet three slots were added for I/O. Two cards were designed by me and published in Radio Bulletin: an ACIA card for two 6850 Motorola ICs, and a PIA card for two PIAs, 6522 or 6520 or 6820 or 6821. I never used more than one ACIA and one PIA card. Shown are the prototype cards, in the article production quality PCBs were used.

PIA and VIA card design by Hans Otten June 1984 Radio Bulletin

ACIA Motorola 6850 by Hans Otten, 1983 Radio Bulletin

On one of the ACIAs a VT100 Digital Equipment terminal was connected, taking over from the bit banged serial interface and the homebuilt video display. ON the other ACIA a Heathkit H14 matrix printer was added, a mediocre but adequate printer.

Together with Micro Ade as assembler and editor, the dual cassette deck, 40K RAM In total, this was a nice machine! Until 1987, when I bought the Spectravideo X’Press 738 MSX and CP/M system, used for all my publishing activities.

A third expansion cabinet was built around 1983. It was driven by the PIA’s, the Radio Bulletin Grafisch Display was inside the cabinet, along with two MDCR Philips Digital cassette recorders, alo published in Radio Bulletin. The speed difference between Hypertape audio cassettes and 2400 baud MDCR speed was not that impressive.

Dirk Dral

EPROM card (Dirk Dral)

The other set is the result of assembling the source in which the assembler used $FF for the filler bytes. It makes sense to use $FF, since EPROMs can be programmed byte for byte ‘1’ later to ‘0’s.
Functionally the filler byte is irrelevant, so I present here the ROMs with filler byte 00 (corrected Dwight original KIM-1 dumps) and filler byte FF (assembly result).

6530-002 $1C00-$1FFF, filler bytes $FF 6530-002 ROM
6530-003 $1800-$1BFF, filler bytes $FF 6530-003 ROM

6530-002 $1C00-$1FFF, filler bytes $00 6530-002 ROM
6530-003 $1800-$1BFF, filler bytes $00 6530-003 ROM

Replicated here the are relevant text and schematics by Ruud.

Build a KIM-1

The goal of this project is to rebuild the KIM-1. This isn’t “Just take the schematic of the KIM and go ahead!”. The KIM-1 uses two 6530s that are custom ICs and therefore cannot be bought in any shop. This project uses replacement parts.
The troubleshooter: 6530
As said, the KIM-1 has two 6530s on board. For more info about this IC, please read about the 6530 here. Anybody who is a little bit familiar with the hardware market can tell you that you cannot buy the 6530 as a regular part. And the 6530 is a custom IC: Commodore made various types but all were branded 6530. For example, the 6530 found in the CBM 4040 drive is different from the ones of the KIM. Even the two 6530s of the KIM itself are different: in this case it is the content of the builtin ROM.
Happily enough there is another IC available that can be used as replacement: the 6532.

The 6532 has 16 I/O lines, an internal timer and 128 bytes of RAM onboard, but no ROM. For this project we’ll use an external EPROM as replacement. The pin out of the 6532 is completely different but that should not be a problem.
Another difference is that a 6532 has pin PB6 available where a 6530 hasn’t. See it as a bonus as I haven’t found any reason how it could jeopardize our project.
The 6530 can generate a IRQ but in case of the KIM-1 this feature isn’t used. The main reason is that pin PA7 is needed to output the signal and it is used for other things. The 6532 has a separate IRQ output. I used two jumpers, J54 and J5, to enable someone to use this function if needed.
The last and major difference however lays in the way the registers are selected:

function:       RS:  A6:  A5:  A4:  A3:  A2:  A1:  A0:  R/W: 
                                                            
RAM              0    x    x    x    x    x    x    x    x   
                                                            
DRA              1    x    x    x    x    0    0    0    x     A
DDRA             1    x    x    x    x    0    0    1    x     B
DRB              1    x    x    x    x    0    1    0    x     C
DDRB             1    x    x    x    x    0    1    1    x     D
                                                            
PA7, IRQ off,                                               
      neg edge   1    x    x    0    x    1    0    0    0     F
PA7, IRQ off,                                               
      pos edge   1    x    x    0    x    1    0    1    0     G
PA7, IRQ on,                                                
      neg edge   1    x    x    0    x    1    1    0    0     H
PA7, IRQ on,                                                
      pos edge   1    x    x    0    x    1    1    1    0     I
                                                            
read interrupt                                              
       flag      1    x    x    x    x    1    x    1    1     E
                                                            
read timer,                                                 
       IRQ off   1    x    x    x    0    1    x    0    1     J
read timer,                                                 
       IRQ on    1    x    x    x    1    1    x    0    1     K
                                                            
Clock / 1,                                                  
       IRQ off   1    x    x    1    0    1    0    0    0     L
Clock / 8,                                                  
       IRQ off   1    x    x    1    0    1    0    1    0     M
Clock / 64,                                                 
       IRQ off   1    x    x    1    0    1    1    0    0     N
Clock / 1024,                                               
       IRQ off   1    x    x    1    0    1    1    1    0     O
                                                            
Clock / 1,                                                  
       IRQ on    1    x    x    1    1    1    0    0    0     P
Clock / 8,                                                  
       IRQ on    1    x    x    1    1    1    0    1    0     R
Clock / 64,                                                 
       IRQ on    1    x    x    1    1    1    1    0    0     S
Clock / 1024,                                               
       IRQ on    1    x    x    1    1    1    1    1    0     T

In total 5 address lines are used, meaning 32 registers. But 11 of the 19 registers have one or more mirrors.

Read:          J E J E         K E K E         J E J E         K E K E 
Write:         F G H I         F G H I         L M N O         P R S T 
R/W:           A B C D         A B C D         A B C D         A B C D         

As we can see, the last 16 registers equal the 16 of the 6530 itself. So now we have to develop some logic which will do the following:

• The I/O of the 6532 is only visible within a range of 64 bytes
• The first 16 bytes represent register 16 to 31
• The next 48 bytes are mirrors of the first 16
• Only 64 bytes of RAM are used

Conclusion:

• Input A6 won’t be used and can be tied to GND
• Input A4 is connected to address line A4 of the 6502 via a NAND gate.
• The second input of that NAND gate is connected to the /CS2 input.
  The idea behind this is simple: The moment that the I/O part of the 6532 is selected, the NAND gate outputs a (H) thus selecting the wanted last 16 registers. If needed, the user can select the other 16 registers as well by connecting the second input of the NAND gate to +5V.
• A 74LS138 enables the /RS and /CS2 lines at the right moment.

ROM and RAM
Here we have a luxury problem. We only need 2K of (EP)ROM like the 2716. The problem is that the 2716 is hard to find and more expensive then the 2764 or its bigger brothers. When we use a bigger EPROM we could tie the unused address lines to GND.
The same problem occurs with the RAM. In this case I have chosen for a 62256, a 32 KB RAM. This looks like a massive overkill but see later.
If we have to use bigger RAMs or EPROMs anyway, it is quite easy to use other parts of that chip by OR wiring the CS line with more Kx outputs of the main 74145. In case of the EPROM we also can connect switches to the surplus address lines and have the advantage of a multi-KERNAL system.

Extra address range
KIM-1 only supported an address range of 8 KB in the first place. The pin DECEN at the Userport can be used to extend that range but HAS to be connected to GND for the original configuration. The idea is that external cards can use this input to alter the range.
I added an extra 74145, IC7, and two jumpers that enable the user to make a more efficient use of the hardware. Both jumpers, J2 and J3, have to be closed to start with.
If you don’t want to use the 74145 at all, only close jumper J1.

The first thing one can do is to let the binary start at address $F800. Your self built KIM will still behave as usual. Now you can add your own RAM from address $0000 on up to $E000 and the only thing you have to do is remove jumper J2.
If you are only interested in adding RAM, a better idea is to use the original one, IC4, the 62256 32 KB RAM. You only have to remove the jumpers J13..17 and to close one or more pair of pins of jumper block J18. By closing all four pair of pins you make use of the full 32 KB.
Jumper J3 is only needed if you want to expand your self built KIM even further and want to use, for example, the $E000/$FFFF range for (EP)ROM.

Schematics of the new KIM-1

What are the major differences with the original schematic?

• Replacement of the 6530s by 6532s.
• Addition of two NAND gates to handle the 6532s.
• Addition of an EPROM.
• Replacement of the 6108 RAM ICs by a 62256 or equivalent 32K*8 SRAM.
• Addition of a 74LS138 to decode the RAM and I/O of the 6532s.
• The resistor for K6 has been dropped.
• Addition of jumpers to enable the combination of other K lines.