Search found 85 matches

by Mike Chambers
Apr 30, 2011 5:34
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

@Mike Chambers i'm a bit of a vintage computer geek. you should see my classic IBM 5150 and 5160s! :D Can I give you my email addr? I think we're both pretty vintage computer geeky and I could relate some of my stories. kiyotewolf [at] gmail [dot] [com] ~Kiyote! Also, I'm at a bit of a standstill o...
by Mike Chambers
Apr 06, 2011 22:20
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

'==================================================================== #include once "windows.bi" #include "counter.bas" '==================================================================== '' Counter.bas is available here: '' '' http://www.freebasic.net/forum/viewtopic.php?t=42...
by Mike Chambers
Apr 06, 2011 22:17
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

that crossed my mind actually, fxm. i wonder if it's faster than select case as const. probably not, but it's worth a try.
by Mike Chambers
Apr 06, 2011 22:04
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

ah, never used it under QB either. i've got lots of QB experience, but the need never arose. i wonder why the small limit.
by Mike Chambers
Apr 06, 2011 21:53
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

The jumping being wrong with ON ... GOTO is actually a bug, the compiler is soft-limited to 64 target labels but it does not check that limit yet but just does something more or less random... ah, okay then i'm not insane. i wasn't seeing what the problem could have been. select case as const sped ...
by Mike Chambers
Apr 06, 2011 21:39
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

h4tt3n wrote:Isn't if...else supposed to be considerable faster than select case? Maybe some speed could be gained that way without all the jumptable stuff?

Cheers,
Mike


yeah i think you're right, it is supposed to be faster. dkl's suggestion worked wonders though!
by Mike Chambers
Apr 06, 2011 21:38
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

dkl wrote:Maybe not much of an optimizing compiler, but... it has SELECT CASE AS CONST for the jump table thing!


wow, didn't know about that. based on benchmark programs i'm running inside my emu, that DOUBLED the speed! :D
by Mike Chambers
Apr 06, 2011 21:19
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

now, here's what i've done to convert it into an On ... Goto jump table. problem is, things aren't jumping to the right places and i can't figure out why for the life of me. i've never used On ... Goto before, but it looks like it should be really straightforward on the wiki: opjump = opcode + 1 On ...
by Mike Chambers
Apr 06, 2011 21:17
Forum: General
Topic: optimizing a huge Select Case block using On ... Goto
Replies: 18
Views: 1994

optimizing a huge Select Case block using On ... Goto

before the Goto haters shoot me in the head, i don't like using Gotos if i can help it but with this particular bit of code.. speed optimization is CRITICAL! it's part of an 8086 PC emulator, where it checks what opcode is about to be run, and then takes appropriate action. according to the wiki, FB...
by Mike Chambers
Mar 20, 2011 19:12
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

i don't have a model 25 (I WISH I DID IVE BEEN LOOKING FOR ONE) but i don't believe you can disable the onboard video. there would be a memory overlap issue between the VGA and that anyway. and yeah it's no fun if its not on the internal monitor. :) i do have a PS/2 model 8580, but thats not at fun....
by Mike Chambers
Mar 20, 2011 16:13
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

nope a Model 25 has MCGA graphics, not VGA. it does not support unchained mode.
by Mike Chambers
Mar 20, 2011 7:56
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

if anybody wants to try it in it's current state, here's a download including a 50 MB hard disk image for it. it's blank except for DR-DOS 3.40, and for fun, Borland Turbo C++ 1.01 :) it's legal to include that, Borland put that version in the public domain some years ago. there's another 40 MB or s...
by Mike Chambers
Mar 18, 2011 1:46
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

i would rather not direct link to it since this is a public forum, and even though this is ancient abandonware it might be against the rules but you can find it at www.myabandonware.com

type indianapolis in the search box, it will show a few results but its in the list.
by Mike Chambers
Mar 18, 2011 1:23
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

if anybody wants to know, i've made a ton of progress. i gutted the CPU core and re-wrote it from scratch. still don't know what the deal was with the old code, but it works good now.

here's a video of it running Indy 500!!
http://www.youtube.com/watch?v=L4u5I8c74a0

:D
by Mike Chambers
Mar 04, 2011 20:04
Forum: Projects
Topic: x86 PC emulator in pure FreeBASIC
Replies: 61
Views: 21078

Which part of the program decodes the actual numeric values of the ASM code, into the appropriate OP CODES? Either I haven't looked everywhere, or I keep missing it. I'd like to see where you're actually decoding the individual bytes of ASM code. Also, how do you store variables in 8086 ASM? How do...

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