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CPM-65 and Elekterminal emulator

CPM-65 and Elekterminal emulator

CPM-65, a CP/M-80 like operating system for 6502 based microcomputer Dietrich Lausberg build a Junior long ago and expanded it to ...

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Elektor books Junior and Computing

Elektor books Junior and Computing

Added to the Elektor book pages: - Junior Book 1 Francais - Elektor Computing German 1-6

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KIM-1 Enhancement PROM

KIM-1 Enhancement PROM

This source for an enhancement of the KIM-1 contains Jim Butterfield's Supertape and some other utilities and code. The PROM is ...

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OUP/M – A 6502 CP/M Operating system

OUP/M - A 6502 CP/M Operating system

A thesis by Jian - Xiong Shao, 1983, titled OUP/M - A 6502 Operating system, contains a floppy disk based ...

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More Elektor Junior

More Elektor Junior

I think I am for now finished with the Junior pages: On request I recreated the Junior book 3 to ...

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Elektor Junior pages updated

Elektor Junior pages updated

After several years so much new and correct information has been coming in! While I was studying the Comal interpreter, I ...

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Italian Junior articles archive

I found scans of the Italian Elektor magazine 1-62 on the web! Here you find the relevant Junior/6502/Z80 articles from ...

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SYM-1 RAE-1 Reference manual, version of 1980

SYM-1 RAE-1 Reference manual, version of 1980

Read here: New manual uploaded: SYM-1 RAE-1 Reference manual, version of 1980. Scan by Rob Ward, thanks Rob!

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Focal runs on KIM-1 Simulator

KIM-1 Simulator version 1.1.6 has been published. Get it here. It now supports Focal-V3D 12-AUG-77 (the Aresco version) from the KIM-1 ...

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Testing the 6530-002 RRIOT with a KIM-1

Testing the 6530-002 RRIOT with a KIM-1

This article is written by Jeff M. Nay, about his experiments to restore a KIM-1 to working order. The challenge ...

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KIM-1 and TIM updates

KIM-1 and TIM updates

I have added the following to the KIM-2 KIM-3-KIM-4 KIM-5 KIM-6 pages: - brochure with photos and descriptions and pricelist KIM ...

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Lost pages of Andrew Jacobs

Lost pages of Andrew Jacobs

The late Andrew Jacobs set up a web site with relevant 6502 information. It is lost now. This site is reproduced ...

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EMUF 6502 MC 1985

EMUF 6502 MC 1985

Thanks to Gerold Pauler I have added an article from MC 1985 about an EMUF6502 with more ROM, RAM and ...

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macOS compiled version of KIM-1 Simulator

macOS compiled version of KIM-1 Simulator

Thanks to user hobo of https://groups.google.com/g/pal6502 a macOS compiled app is now included.

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KIM-1 Circuit Diagram high resolution poster, cleaned up again

A couple of weeks I published the KIM-1 Circuit Diagram in high resolution, cleaned up by Joshy of Forum64. Since then ...

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AIM 65 Assembler ROM R3224 source

On the pagetable Commodore source archive I found the source of the AIM 65 Assembler ROM R3224. Now on the AIM ...

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Who were involved in the development of KIM-1 and TIM?

The 6530-002 (the KIM monitor), 6530-003 (the KIM tape routines) and 6530-004 (TIM, the teletype monitor) are in the ROM ...

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Data Handler

Data Handler

Armin added to his blog page on the Data Handler a Rev Manual with his permission reproduced here.

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CT-6502 Thaler

CT-6502 Thaler

A small PCB (2x Eurocard) with a KIM-1 like 6502 system.Made by Thaler, Germany.I have now this computer, with the ...

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PROMAX MI-650 trainer

PROMAX MI-650 trainer

1979 - PROMAX MI-650 trainer Educational trainersEducational instruments division was the result of our close commercial relationships with universities and ...

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This page is about my interest in retro 8-bit small computer systems computing and electronics. And the role of Dutch electronic magazines like Elektuur and Radio Bulletin in the eighties of the 20th century. Also the Dutch users club, called KIM Gebruikersclub, which I joined in 1978 and contributed to as member of the board and as chief editor of the magazine issue 11 to 25.
The retro computing pages are documenting my experiences with 8-bit systems like the KIM-1 and its relatives such as the Apple 1 and the Junior. And various small Z80 and other systems.
I set up this archive as my personal archive of what I research on the subject. If it is of any use for others, fine, enjoy!

Magazines

In the early days of computing, magazines about popular electronics played a big role in making microprocessors available for the beginner, whether the professional or hobby electric engineer.  The magazines featured here are the dutch magazines Elektuur and Radio Bulletin. From 1977 until 1996 I worked as technical editor for Radio Bulletin and published about microcomputers and more general electronics.  Elektuur published also articles on these subjects, many are available here.

What is a SBC for me?

A SBC, short for Single Board Computer can be defined as a computer system, based on a microprocessor, on one printed circuit, with keyboard and display, programmable I/O ports, expansion connectors and without a casing. The ‘operating system’ is stored in a (EP)ROM, an often small amount of RAM is available to store programs and data These were the first microprocessor based computers with affordable prices for hobbyists in the late seventies of the previous century. For professionals a way of getting acquainted with the new hardware and learning the basics of programming at a (very!) low level.

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Though it is a complete computer, it has a CPU, memory and I/O, it is also a very limited one. The I/O is often not more than a small keyboard with hexadecimal functions. The display is often not more than 6 or 8 seven segment LED displays, just enough to show, in hexadecimal format, addresses and data. The operating system allows entering and examining of data in memory locations, and start and stop a program. Loading and saving data is limited to either papertape readers and punches, quite common in these days, or via some modulation as data files on audio cassette recorders. Also common is the ability to attach a teletype like the ASR33.

A good example of such a SBC is the KIM-1, shown below. 2K ROM, 1K RAM, many I/O lines free, six LED displays and a keyboard with hexadecimal keys and some function keys.
Why these SBCs like the KIM-1 became so popular? One reason was the low price ($ 280 for a KIM-1, I paid 795 guilders ), so it was in the price range of the average student and hobbyist. Another is the design being open, the complete hardware description and detailed listing of the ROM was included. And it is not the frightening computer, but more a programmable piece of hardware. Because it was so easy accessible and low speed, adding and changing hardware is not hard also. Programming was not easy, but editors/assemblers that could run with some added hardware like RAM and a video terminal made that possible. The nowadays common practice of cross compiling was not available for the hobbyist then.

Besides playing with the SBC, to learn what the microprocessor is capable of, many SBCs were put to work as a sort of PLC, controlling devices in the real world.
What changed the popularity of SBCs was the wish to transfer it to a computer with a better user interface, like graphics on a video screen, a full blown keyboard, a real operating system with mass storage such as floppy drives, and a higher fun factor, a.k.a. games. Or to make it a serious computer fit for business. So SBCs became extinct fast in the mainstream hobby world when the hobbycomputer appeared on the market, like the TRS-80, PET and later the C-64, MSX etc. Even later the boring business PC killed the hobby computer, but that is another story.
It seems the SBC’s are back though: Arduino and Raspberry Pi and the availability of cheap Chinese electronic shops and cross compilation on the PC make it possible to play affordable with small programmable devices at a lower level.

This site is mostly specialized on the 6502 and Z80 SBC (Single Board Computer), small computers based on an 8 bit microprocessor. Good for learning about digital electronics and programming at a lower level. And for many the start of their career in computer science.
SBCs featured here are systems like KIM-1, Apple 1 and equivalent boards like the A-ONE, Apple 1 Replica, Micro-KIM, Elektor Junior, AIM-65, SYM-1, RC2014, TEC-1, MBC-2 and such.

Please use the Contact form to contribute to this fascinating hobby!
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