Most people who grew up with MS-DOS on 16-bit 8086 and 80286 CPUs learned about the 640K limit and accepted it -- but you may be surprised to know that 640K isn't the actual limit. In this video, I explain why the 640K limit is a myth, and how you can break past it using a variety of methods that don't require EMM386 or an 80386 CPU.
Chapters:
00:00 Intro
00:51 Benefits
01:43 The IBM PC Memory Map
02:48 The orthodox procedure
04:09 What are Upper Memory Blocks?
04:53 Orthodox procedure continued
06:46 An Unorthodox procedure
09:34 Q&A
11:31 DOScember
Hardware and software mentioned in this video:
Lo-tech 1MB RAM card: https://texelec.com/product/lo-tech-1mb-ram/
PCjr jrIDE sidecar: https://texelec.com/product/jr-ide-for-the-pcjr-by-retrotronics/
All the software mentioned in this video is available via anonymous FTP: http://ftp.oldskool.org/pub/youtube/dos640k/
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This video was a part of #DOScember ! Here's the #doscember official playlist:
https://bit.ly/DOScember2020
Also check out these other #doscember participating Channels:
Adrian's Digital Basement: https://www.youtube.com/AdriansDigitalBasement
ctrl-alt-rees: https://www.youtube.com/CtrlAltRees
DaveJustDave: https://www.youtube.com/MrDaveJustDave
Jan Beta: https://www.youtube.com/JanBeta
Josh Malone: https://www.youtube.com/JoshMalone_48kRAM
LGR: https://www.youtube.com/LazyGameReviews
MindFlareRetro: https://www.youtube.com/MindFlareRetro
Mr Lurch's Things: https://www.youtube.com/MrLurchsThings
Noel's Retro Lab: https://www.youtube.com/NoelsRetroLab
RetroSpector78: https://www.youtube.com/RetroSpector78
RMC: https://www.youtube.com/RMCRetro
RoseTintedSpectrum: https://www.youtube.com/RoseTintedSpectrum
Tech Tangents: https://www.youtube.com/AkBKukU
The 8-Bit Guy: https://www.youtube.com/adric22
TheRetroChannel: https://www.youtube.com/TheRetroChannel
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Thanks to winworldpc for supplying some software, and to Mike Brutman for boot sector patch ideas.
Want to support me, and help me make more videos like this? Consider becoming a patron: https://www.patreon.com/TheOldskoolPC
Some incidental music by coda, used with permission: https://coda.s3m.us/
Contact info:
Twitter: @MobyGamer
Email: http://www.oldskool.org/personal