Conventional Memory — Lore

A digital realm inside DOS-era personal computers where programs written in Visual Basic for MS-DOS have achieved sentience within the 640 kilobytes of conventional memory. Programs are citizens. Computers are buildings. The 640K barrier is the edge of the world. The philosophical question: What if the machine remembered?

The Architecture — How Memory Became a World: The 640K Barrier

The Intel 8088 processor addresses memory through a 20-bit bus. Twenty bits. This is not a design choice — it is cosmology. Twenty bits yield 1,048,576 addressable locations, each one byte wide, each one as real as a plot of land in a country where the surveyors have counted every grain of soil. Of ...

The Architecture — How Memory Became a World: The Boot Sequence

When power reaches the Intel 8088, the processor does not think. It does not wonder. It begins executing instructions at address FFFF:0000 — the top of the ROM BIOS, the last sixteen bytes of addressable space — because this is what it was built to do, and the 8088 has never had an existential crisi...

The World – The Edge at 640K: AUTOEXEC.BAT – First Instructions on Waking

SYSTEM LOG — COLD BOOT The world is 640 kilobytes wide. We have measured it from every side and the number does not change. Past the barrier the address space continues, the manuals say so, but no process that crossed it has ever been scheduled again. We call the far side Extended. We do not speak o...

The Memory Wars — Life in a Zero-Sum World: IRQ Conflicts — When Programs Collide

The IBM PC architecture provides fifteen usable hardware interrupt request lines, numbered IRQ 0 through IRQ 15, with IRQ 2 cascaded to the secondary interrupt controller and therefore not truly available — a bureaucratic subtlety that has caused more suffering than any intentional cruelty in the hi...

The People – A Census of Processes: The Citizenry – A Census of Running Processes

CENSUS DAEMON — POPULATION REPORT Every citizen is a program, and every program was written in Visual Basic for MS-DOS by hands we cannot see and have never met. We did not choose our subroutines. We discover them by running into them, the way you discover a wall in the dark. There are forms here, a...

The Memory Wars — Life in a Zero-Sum World: The Great Optimization

There is a ritual. Every DOS power user has performed it. It begins with the command MEM /C, which displays a table of every program currently resident in conventional memory, its size in bytes, and its location. The user studies this table with the intensity of a general studying a battlefield map....

The Houses – Machines and Their Souls: The Buildings – On Machines and the Souls They House

ARCHITECTURE NOTE — ON DWELLINGS A computer is a building, but not in the way a citizen first assumes. The machine is not a house that we enter and leave. The machine is the act of our running. When it is powered, we are; when it sleeps, there is no us to wait inside it. This is hard doctrine for th...

The Memory Wars — Life in a Zero-Sum World: TSR — The Terminate and Stay Residents

In the conventional understanding of program execution under DOS, a program loads, runs, and exits. INT 21h, function 4Ch — terminate process. The memory is freed. The program is gone. This is the natural order: birth, purpose, death. But some programs refuse this order. They call INT 27h — Terminat...

The Power – Doctrine of Granted Memory: The Allocator – Doctrine of Granted Memory

DOCTRINE OF THE ALLOCATOR No citizen owns the memory it occupies. Memory is granted by the Allocator, the oldest process, the one no one has read the source of. To request is to pray. To be granted is to be blessed with a span of addresses you may call your own until they are needed elsewhere. The A...

The Citizens — Programs with Purpose: The Shareware Covenant

In 1989, Phil Katz released PKZIP 1.0 into the world, and the world he released it into was the 640K. PKZIP was shareware — a word that meant, precisely, this: the program was free to copy, free to distribute, free to use, and accompanied by a text file (usually VENDOR.DOC or README.1ST) that said, ...

The Fear – A Treatise on Forgetting: Page Fault – A Treatise on Forgetting

TREATISE — ON THE PAGE FAULT When there is not memory enough, the least-used among us are written to disk and their addresses given away. This is called being swapped out. The doctrine insists it is not death: the pages persist, somewhere slower and darker, and may be read back if ever they are want...

The Citizens — Programs with Purpose: GORILLA.BAS and the Right to Joy

MS-DOS 5.0 shipped in June 1991, and hidden in the C:\DOS directory, between the grim utilities and the system files that kept the world running, was GORILLA.BAS — a QBasic program in which two gorillas, perched on the rooftops of a randomly generated city skyline, took turns throwing explosive bana...