Recent changes to Home

Home modified by Brian Ruthven

Brian Ruthven — Tue, 19 Aug 2014 22:24:41 -0000

--- v5
+++ v6
@@ -22,7 +22,7 @@

 Above all, this is a learning exercise, so there is a general policy of "don't copy code from anywhere". Yes it's re-inventing the wheel somewhat, but that's kind of the aim here!

-
+[Where to start]
 [Tools]
 [Installation]
 [Disk Images]

Home modified by Brian Ruthven

Brian Ruthven — Mon, 18 Aug 2014 21:01:50 -0000

--- v4
+++ v5
@@ -5,14 +5,14 @@

 SpecOS is a pet project to create a multi-tasking OS for the ZX Spectrum +3 computer.

-SpecOS (in a conceptual form) was born around September 1994, and came to life for real sometime around August 2010. The original idea was based on stack-switching, driven by the 50Hz ULA interrupt.
+SpecOS (in a conceptual form) was born around September 1994, and came to life for real sometime around August 2010. The original idea was based on stack-switching, driven by the 50Hz ULA raster interrupt to the cpu.

 After a 16-year gap, including University and 10 or so years in the computing industry working with Unix, this developed into a general-purpose Unix-style kernel-based model, striving to implement as much as possible without disabling interrupts, and therefore to reduce the amount of time lost e.g. during disk accesses (which CP/M is documented to suffer from).

 #### Aims ####

-   * Must be runnable on real, unmodified +3 hardware with no expansion devices to "assist" or replacement ROMs.
+   * Must be runnable on real, unmodified +3 hardware with no expansion devices to "assist" or replacement ROMs (although a relatively common peripheral of the time with some RAM, like a Multiface could perhaps help out with a bit of extra RAM).
    * Userland processes have no knowledge of other programs running.
    * Userland processes have no knowledge of kernel implementation, load address, etc...
    * Avoid disabling interrupts where possible.

Home modified by Brian Ruthven

Brian Ruthven — Wed, 03 Jul 2013 23:15:14 -0000

--- v3
+++ v4
@@ -7,12 +7,12 @@

 SpecOS (in a conceptual form) was born around September 1994, and came to life for real sometime around August 2010. The original idea was based on stack-switching, driven by the 50Hz ULA interrupt.

-After a 16-year gap, this developed into a general-purpose Unix-style kernel-based model, striving to implement as much as possible without disabling interrupts, and therefore to reduce the amount of time lost e.g. during disk accesses (which CP/M is documented to suffer from).
+After a 16-year gap, including University and 10 or so years in the computing industry working with Unix, this developed into a general-purpose Unix-style kernel-based model, striving to implement as much as possible without disabling interrupts, and therefore to reduce the amount of time lost e.g. during disk accesses (which CP/M is documented to suffer from).

 #### Aims ####

-   * Must be runnable on real, unmodified +3 hardware with no expansion devices to "assist".
+   * Must be runnable on real, unmodified +3 hardware with no expansion devices to "assist" or replacement ROMs.
    * Userland processes have no knowledge of other programs running.
    * Userland processes have no knowledge of kernel implementation, load address, etc...
    * Avoid disabling interrupts where possible.
@@ -20,6 +20,7 @@
    * Must be "thread-safe" (i.e. preemptible at any point).
    * Userland processes can also be compiled natively under Unix (with some helper library support).

+Above all, this is a learning exercise, so there is a general policy of "don't copy code from anywhere". Yes it's re-inventing the wheel somewhat, but that's kind of the aim here!

 [Tools]

Home modified by Brian Ruthven

Brian Ruthven — Tue, 04 Jun 2013 13:41:35 -0000

--- v2
+++ v3
@@ -24,6 +24,7 @@

 [Tools]
 [Installation]
+[Disk Images]

 [[members limit=20]]

Home modified by Brian Ruthven

Brian Ruthven — Tue, 07 May 2013 20:18:41 -0000

--- v1
+++ v2
@@ -1,8 +1,30 @@
-Welcome to your wiki!
+## Welcome to SpecOS! ##

-This is the default page, edit it as you see fit. To add a new page simply reference it within brackets, e.g.: [SamplePage].

-The wiki uses [Markdown](/p/specos/wiki/markdown_syntax/) syntax.
+#### What is SpecOS ####
+
+SpecOS is a pet project to create a multi-tasking OS for the ZX Spectrum +3 computer.
+
+SpecOS (in a conceptual form) was born around September 1994, and came to life for real sometime around August 2010. The original idea was based on stack-switching, driven by the 50Hz ULA interrupt.
+
+After a 16-year gap, this developed into a general-purpose Unix-style kernel-based model, striving to implement as much as possible without disabling interrupts, and therefore to reduce the amount of time lost e.g. during disk accesses (which CP/M is documented to suffer from).
+
+
+#### Aims ####
+
+   * Must be runnable on real, unmodified +3 hardware with no expansion devices to "assist".
+   * Userland processes have no knowledge of other programs running.
+   * Userland processes have no knowledge of kernel implementation, load address, etc...
+   * Avoid disabling interrupts where possible.
+   * Avoid memory fragmentation.
+   * Must be "thread-safe" (i.e. preemptible at any point).
+   * Userland processes can also be compiled natively under Unix (with some helper library support).
+
+
+
+[Tools]
+[Installation]
+

 [[members limit=20]]
 [[download_button]]

Home modified by Brian Ruthven

Brian Ruthven — Sat, 04 May 2013 11:11:28 -0000

Welcome to your wiki!

This is the default page, edit it as you see fit. To add a new page simply reference it within brackets, e.g.: [SamplePage].

The wiki uses Markdown syntax.

Project Members:

Brian Ruthven (admin)