Microsoft’s 6502 BASIC is now Open Source

Microsoft’s 6502 BASIC is now Open Source, and that includes KB9 or as it is officially called:

MOS TECH 6502 BASIC V1.1
COPYRIGHT 1977 BY MICROSOFT

Microsoft’s 6502 BASIC is now Open Source

“Now, for the first time, this influential 6502 version is truly yours to explore, modify, and share.”

This means that we are allowed to distribute and modify KB9 and derivates without breaking licenses!

Also see the pagetable post from 2005 that explains a lot about this source.

The Easter Egg in KB9:

Answer ‘A’ to the Memory Size Qustion and see this:


Now we all know about Bill Gates. Ric Weiland is less known. Second Micro-Soft employee. Left 1988, and became a philanthropist, see Wikipedia.

The license that goes with 6502 BASIC is now:

MIT License

Copyright (c) Microsoft Corporation.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the “Software”), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE

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Magazines: Compute! and Compute II

The pages om Magazines had an update.

MICRO has its own page with all Best of MICRO pfds.
Compute! and Compute II articles have been highlighted.

A special page devoted to a small program called Dungeons And Dragons Dice Simulator, with source and demo

Vorstellung: The 6502 50th Anniversary Computer Badge (1975-2025)

The 6502 50th Anniversary Computer Badge (1975-2025), variant of Lee Hart’s 6502 badge, to celebrate the 6502 birthday.

On the German forum64.de

#50birthday6502

January 2026, the 50th birthday of the KIM-1

n 1975 MOS Technology started delivery of 65XX ICs. So 2025 marks the 50 year anniversary of the 6502!
The earliest mentions of the KIM-1 are from January 1976. The date of the first edition of the User Manual, and first mentions in e.g. Byte.
So I propose to declare January 2026 as the 50th birthday of the KIM-1!
#50yearsKIM1

How to use the time in the 6530/6532

When I acquired a KIM-1 Rev A, obviously sold by NCE/Compumart, it came with some documentation that may interest any programmer working with the MOS Technology (R)RIOT 6530 and 6532.

The timer description the datasheet is a bit vague about how to use. What may help is the document ‘KIM-1 Application Note 2 Interval Timer Operation’ by MOS Technology.

A document with listings of KIM-1 programs called ‘KIM-1 Application Programs CT1’ illustrate the usage of the timer in interrupt mode. You find the documents here:
Compumart KIM-1 Rev A – Retro Computing

PLEASE package The Computerist

PLEASE is a very small package for a standard KIM-1. It has a tiny monitor, command interpreter and many handy subroutines.

PLEASE INSTRUCTIONS
PLEASE LISTING

A small book with five experiments with the KIM-1

A small book with five experiments with the KIM-1.
1. User
2. Input/output
3. I/O controller
4. Timing
5. Hardware interrupts

KIM-1 experiments)

MOS Technology KIM-1 Preliminary datasheet 1976

With one of my KIM-1s (a Rev G) came a MOS Technology KIM-1 Preliminary datasheet 1976.

Added to the KIM-1 manuals page.


Facebook, not now

I am administrator of several Facebook groups. But not at the moment. So if you came here looking why I am absent on Facebook starting August 22, read this: I am well, my Facebook account is not.

I am not a fan of Meta and the way they treat privacy, so I do not post any personal info there anymore and unfriended nearly all.
Meta also started to target personal advertisement in a more aggressive way, even blocking access for a couple of seconds on the phone to force me to accept that.
I stopped therefore a long time ago posting personal information.

But these groups are retro computing related, with a nice atmosphere and many members, of which I am the administrator and a major contributor:
– KIM-1, SYM-1, AIM 65, Elektor Junior and clones (over 1000 members)
– 6502 CPU family (over 4000 members)
– The School of Wirth (a dozen members)

Out of the blue Facebook blocked my access on August 22, I have not obeyed their ‘community rules’. Must be because I link to my websites a lot. Facebook hates people going offsite!

At the moment I am not allowed back in, I have appealed and wait for Facebook. It could mean permanent blocking and the groups will suffer.
There are backup admins, so they may survive.

If I am permanently blocked, my regards and good wishes to all members of the groups I administer!

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All documents in the MTU pages are now clean and higher quality, about 50 new PDFs.

I got hold a about 10 cm of MTU documents. Several I already had in PDF format, some not available yet.
I took the opportunity to scan/rescan/repair what I have online until now.
All documents in the MTU pages are now clean and higher quality, about 50 new PDFs.

Noteworthy are the new revised K-1008 September 1979 document and the now complete and revised K-1013 manuals and 2 versions of the CODOS V1 manual.
All the K-1002 documents, for KIM-1, SYM-1, AIM 65 and Commodore PET are new.

Micro Technology Unlimited – Retro ComputingMTU history: Hal Chamberlin
MTU Catalogs, Product Descriptions and Newsletters
MTU Application notes
MTU K-1000 power unit
MTU K-1002 Audio D/A Converter
MTU K-1005 Card File and Motherboard using KIM/MTU bus
MTU K-1007 PET MTU bus interface
MTU K-1008 Visable Memory
MTU K-1008 documents
Dave Plummer has a K-1008
The K-1008 and the KIM-1 Simulator
Graphics Software Package K-1008
K-1008 Test programs
K-1008-2L Patches to Microsoft BASIC
K-1008 Visable Memory Replica by Eduardo Casino
MTU K-1009-1C AIM 65 Printer Enhancement Package
K-1012 PROM expansion board
K-1013 floppy controller
MTU CODOS
MTU K-1016 16K RAM board
MTU K-1020 Prototyping board
MTU K-1032 Banker RAM ROM I/O