News

Last updated 2007-12-07

2007-12-07

• Version 0.0.4 released
• CPU - added 92 instructions
• Virtual Keyboard :-
• Added a virtual keyboard (vkeyb)
• ROM :-
• INT 9
• PIT :-
• Renamed the timer to Programmable Interval Timer
• PIC :-
• Added a Programmable Interrupt Controller to manage external interrupts
• Keyboard :-
• INT 16 Service 00 Read Next Keyboard Character
• DOS :-
• INT 20 Program Terminate
• INT 21 Function 3C Create File
• Video :-
• Fixed the video refresh timer @ 20ms (50Hz)
• Overall :-
• Optimised and performance tested
• It's now possible to specify a program to emulate via the command line
• Additional command line options include :-
•   video dimensions, frameskip and fullscreen
•   CPU delay initial value and increment
• A simple DOS VGA freeware Pac-Man game (included and shown below) can be emulated

2007-05-05

I've been unable to work on any of my projects since January 2007 (my development system requires reassembling) but I intend to get back into the swing of things very soon. I did manage to get an old DOS VGA game emulated perfectly with working virtual keyboard (see image below) but I didn't get a chance to package and upload it. I can report though that it's very fast on the Sharp Zaurus SL-5500 so things are looking very good indeed.

2006-12-02

• Version 0.0.3 released
• CPU - added 53 instructions
• Timer :-
• Channel 0 timer - system (clock-tick) timer @ 20ms
• Keyboard :-
• INT 16 Service 01 Report Whether Character Ready
• ROM :-
• ROM and ROM BIOS
• Interrupt vector table
• INT 8
• INT 1A Service 00 Time-of-Day Services
• INT 1C (triggered by INT 8)
• DOS :-
• INT 21 Function 42 Move File Pointer
• INT 21 Function 48 Allocate Memory Block has been rewritten
• INT 21 Function 49 Free Memory Block has been rewritten
• INT 21 Function 4A Resize Memory Block has been rewritten
• Video :-
• Video mode 13 VGA 256 colours
• Video refresh timer @ 30ms (33fps)
• INT 10 Service 10 Colour Palette Interface
• RAM :-
• Read and write dwords
• Disassembler :-
• Has been considerably restructured
• RAM read/writes can be dumped to the terminal

2006-11-11

• Version 0.0.2 released
• CPU - added 46 instructions
• DOS :-
• INT 21 Function 02 Character Output
• INT 21 Function 09 String Output
• INT 21 Function 4C Terminate With Return Code
• Video :-
• INT 10 Service 00 Set Video Mode
• INT 10 Service 1A Read/Write Display Combination Code
• Disassembler :-
• Improved the memory dumper
• Overall :-
• Optimised and performance tested

2006-11-03

• Version 0.0.1 released
• CPU - added 39 instructions
• DOS :-
• An initial memory block header structure is set-up in the DOS memory array
• A COM file can be loaded into 'memory'
• INT 21 Function 30 Get DOS Version Number
• INT 21 Function 3D Open Handle
• INT 21 Function 3E Close Handle
• INT 21 Function 3F Read from File or Device
• INT 21 Function 48 Allocate Memory Block
• INT 21 Function 49 Free Memory Block
• INT 21 Function 4A Resize Memory Block
• Disassembler :-
• Register dump
• Assembler output
• RAM (memory array) dump