English Amiga Board


Go Back   English Amiga Board > Search Forums

Showing results 1 to 40 of 3474
Search took 0.33 seconds.
Search: Posts Made By: ross
Forum: Coders. Asm / Hardware Yesterday, 19:29
Replies: 50
Views: 2,523
Posted By ross
To tell the truth in this test ZX0 is very much...

To tell the truth in this test ZX0 is very much at an advantage because the file contains a considerable amount of LZ match (but in any case it is significant for comparison with other pure LZs!)....
Forum: Coders. Asm / Hardware Yesterday, 10:23
Replies: 50
Views: 2,523
Posted By ross
The real strength of this compressor is in fact...

The real strength of this compressor is in fact the extensive use of the rep-match, indeed, it is practically completely designed around it
(while in other compressors it is a secondary factor).
I...
Forum: Coders. Asm / Hardware 22 September 2021, 22:37
Replies: 50
Views: 2,523
Posted By ross
WOW. First test with enhanced offset. This...

WOW.
First test with enhanced offset.
This forcibily require my unpacker, the official one doesn't/can't support offset >32KiB.
I used an offset of 100KB, but theoretically in can work until 16MiB...
Forum: Coders. Asm / Hardware 22 September 2021, 17:27
Replies: 50
Views: 2,523
Posted By ross
Ok, now I've a working packer and unpacker for...

Ok, now I've a working packer and unpacker for the 'new' ZX0 stream, optimized and friendly to 68k.

I've tested it with the github mentioned "cobra.scr" (a little file of 6912 bytes, packed to...
Forum: Coders. Asm / Hardware 22 September 2021, 11:01
Replies: 5
Views: 439
Posted By ross
Just some clarifications regarding the maximum...

Just some clarifications regarding the maximum overscan for PAL (the horizontal part is also valid for NTSC).

All the values that I report are seen from the Amiga side, that is the real pixels...
Forum: Coders. Asm / Hardware 21 September 2021, 11:50
Replies: 5
Views: 439
Posted By ross
Total number of scanlines in NTSC is 262 for ...

Total number of scanlines in NTSC is 262 for short frames and 263 for long frames.
So in interlace you have a total of 525 lines.
In Amiga, long frames are normally used for progressive mode.
...
Forum: Coders. Asm / Hardware 17 September 2021, 17:47
Replies: 50
Views: 2,523
Posted By ross
More code unrollolled, more accelerated paths,...

More code unrollolled, more accelerated paths, now I'm near 150 bytes.
Maybe time to stop, I'm at short branches limit.

And I haven't tried with a synthetic stream yet, so nothing might work :)...
Forum: Coders. Asm / Hardware 17 September 2021, 16:21
Replies: 62
Views: 2,131
Posted By ross
This *should* work because ColdReboot do not...

This *should* work because ColdReboot do not seems to read execbase but trust the passed A6, anyway it is probably unsupported.
(EDIT: it internally calls system functions for the caches, supervisor...
Forum: Coders. Asm / Hardware 17 September 2021, 08:29
Replies: 62
Views: 2,131
Posted By ross
You have to choose what to trust. The one I...

You have to choose what to trust.
The one I think is absolutely the least sensitive to a patch is Supervisor() (still someone has to explain to me why a malicious software should patch it without...
Forum: Coders. Asm / Hardware 16 September 2021, 20:44
Replies: 50
Views: 2,523
Posted By ross
Ok, new provisional bitcode defined (EDIT: AZX0?,...

Ok, new provisional bitcode defined (EDIT: AZX0?, name to be defined :)).

The unpacker code is 120 bytes with no subroutines (is unrolled as much as possible) and contains some accelerators, fully...
Forum: Coders. Asm / Hardware 16 September 2021, 20:28
Replies: 62
Views: 2,131
Posted By ross
If you 'degrade' the system with my code, also my...

If you 'degrade' the system with my code, also my manual reset code could be freely used.
If the MMU stuff is to much, simply remove it.

The only dependency is Supervisor()/SuperState(), but I...
Forum: Coders. Asm / Hardware 16 September 2021, 16:47
Replies: 62
Views: 2,131
Posted By ross
This is some code I used. It was a 'mutual...

This is some code I used. It was a 'mutual inspiration' between me and Keirf.
I don't remember if it's a latest version.

It require Supervisor() but I do not see the point for a malicious program...
Forum: Coders. Asm / Hardware 16 September 2021, 16:04
Replies: 50
Views: 2,523
Posted By ross
Well, actually there is a big interest in...

Well, actually there is a big interest in in-place depacking (backward or forward ones).
For one simple reason: many coders don't want to know anything about offsets, safety bytes, pre-set buffers...
Forum: Coders. Asm / Hardware 16 September 2021, 14:02
Replies: 50
Views: 2,523
Posted By ross
I see 3 possible improvements/optimizations that...

I see 3 possible improvements/optimizations that can be applied to the ZX0 68k depacker (apart from the obvious ones concerning micro-optimization), of course modifying the bitcoding structure.
...
Forum: Coders. Asm / Hardware 15 September 2021, 23:41
Replies: 50
Views: 2,523
Posted By ross
Yep, mine was basically a joke, I'm absolutely...

Yep, mine was basically a joke, I'm absolutely aware of how complicated such a thing would be.
Much more feasible to add support for distant offsets (maybe using -q compression, otherwise the...
Forum: Coders. Asm / Hardware 15 September 2021, 22:48
Replies: 50
Views: 2,523
Posted By ross
Add an entropy coding stage to ZX0 :p

Add an entropy coding stage to ZX0 :p
Forum: Coders. Asm / Hardware 15 September 2021, 16:17
Replies: 50
Views: 2,523
Posted By ross
Very nice report. However the purpose is not...

Very nice report.

However the purpose is not clear to me :D
(there is none of the compressors we talked about)

Is it to show compression speeds that are actually acceptable?
Forum: Coders. Asm / Hardware 15 September 2021, 15:27
Replies: 50
Views: 2,523
Posted By ross
The main idea is to cache n offsets from the last...

The main idea is to cache n offsets from the last seen LZ offset/len pairs.
This usually works because the data is sub-related in some way (like arrays or tables).

EDIT: normally the offsets are...
Forum: Coders. Asm / Hardware 15 September 2021, 11:28
Replies: 50
Views: 2,523
Posted By ross
Of course I've no ACME assembler in my toolchain...

Of course I've no ACME assembler in my toolchain so at #include "sfx.h"
compiler stop, and I had to manually remove the sfx code.

Not a problem at all, but maybe a check for the conditional...
Forum: Coders. Asm / Hardware 15 September 2021, 11:10
Replies: 50
Views: 2,523
Posted By ross
Thanks. I've some figures for the speed...

Thanks.

I've some figures for the speed (Zombies.SHP file, 240KiB):
- original version: TotalMinutes 14,95
- 'bitfire' version: TotalMinutes 10,46

So this version is sure faster, but in the...
Forum: Coders. Asm / Hardware 15 September 2021, 01:32
Replies: 50
Views: 2,523
Posted By ross
Oh, great! Maybe a -q version with large LZ...

Oh, great!
Maybe a -q version with large LZ offsets could be a nice compromise.

EDIT:
zx0.exe -q -f Zombies.SHP
File compressed from 245720 to 59796 bytes! ...

But is fast :)
Forum: Coders. Asm / Hardware 15 September 2021, 01:13
Replies: 50
Views: 2,523
Posted By ross
Yes, for sure! In my opinion also a lot can...

Yes, for sure!

In my opinion also a lot can be done to improve the decompression speed for 68k (with different bitcoding).
And I also want to try it with greater LZ distances.
But the big...
Forum: Coders. Asm / Hardware 15 September 2021, 01:07
Replies: 50
Views: 2,523
Posted By ross
With small files seems very good and from the few...

With small files seems very good and from the few tests I made it usually beat the 'LZ only' packers available on the Amiga.
The compression is very slow so put it to work in the background and do...
Forum: Coders. Asm / Hardware 14 September 2021, 21:44
Replies: 5
Views: 399
Posted By ross
This?: subx.w d1,d1 move.w ...

This?:

subx.w d1,d1
move.w d1,-(sp)
; code that could scratch X flag
rtr

;)
Forum: Coders. Asm / Hardware 14 September 2021, 19:49
Replies: 62
Views: 2,131
Posted By ross
I highly doubt that reset code executes from...

I highly doubt that reset code executes from resident vectors without checking checksums first, so if you have IRQs disabled and cleared the vector or checksum and you do a reset, for any virus it is...
Forum: Coders. Asm / Hardware 14 September 2021, 19:23
Replies: 50
Views: 2,523
Posted By ross
Thanks for this, it's a new compressor for me :) ...

Thanks for this, it's a new compressor for me :)

I looked at the decompressor and the documentation very quickly.

I doubt this compressor will be as effective as the ARJm7, but it has to be...
Forum: Coders. Asm / Hardware 14 September 2021, 18:45
Replies: 62
Views: 2,131
Posted By ross
clr.l $2a(a6) EDIT: but if execbase is...

clr.l $2a(a6)

EDIT: but if execbase is destroyed there is no need to clear it..
I explicitly used st 7.w because in any ROM there is a check for an odd execbase address (which of course cannot be...
Forum: Coders. Asm / Hardware 13 September 2021, 22:58
Replies: 50
Views: 2,523
Posted By ross
I've never found any on the Amiga, but...

I've never found any on the Amiga, but potentially something better than ARJm7 could be done.
Main idea could be to substitute huffman stage with tANS and do something for repeating LZ codes.
...
Forum: support.WinUAE 12 September 2021, 23:36
Replies: 2
Views: 324
Posted By ross
Works for me on KS1.2. There is a stupid bug on...

Works for me on KS1.2.
There is a stupid bug on using level 6 IRQ vector (it set an absolute ROM address).
Forum: support.WinUAE 11 September 2021, 23:27
Replies: 14
Views: 523
Posted By ross
I bet setpatch -r doesn't do much differently...

I bet setpatch -r doesn't do much differently than that.
Maybe it will use a lot of overbloated checks but I don't think there are many ways to fix a similar bug that happens in the very initial...
Forum: support.WinUAE 11 September 2021, 23:14
Replies: 14
Views: 523
Posted By ross
a6= execbase a3= right top of chip-ram (and not...

a6= execbase
a3= right top of chip-ram (and not the wrong $80000 hardcoded one)
a5= return code in ROM (the two offset define the faulty code to skip, and I re-enter with a correct a3).

Yes, is...
Forum: support.WinUAE 11 September 2021, 23:08
Replies: 14
Views: 523
Posted By ross
Example code to use it: moveq #0,d2 ...

Example code to use it:
moveq #0,d2
cmpi.w #KS13,lib_Version(a6)
bne.b .skip
move.l #ColdCapture_code,ColdCapture(a6)
move.w d2,LowMemChkSum(a6)
lea SoftVer(a6),a0
moveq #$18,d0...
Forum: support.WinUAE 11 September 2021, 22:56
Replies: 14
Views: 523
Posted By ross
My fix for 1.3. You need to execute it very...

My fix for 1.3.
You need to execute it very early on KS startup (you only can do it at ColdCapture time because after is to late..)

From 2.0+ >=1MB chip-ram and reset-proof code is properly...
Forum: Coders. Asm / Hardware 11 September 2021, 22:49
Replies: 62
Views: 2,131
Posted By ross
No, 'brutal code' do not clear RAM, it only...

No, 'brutal code' do not clear RAM, it only destroy execbase so system is constrained to rebuild all from scratch.
But I think there is no clear-ram code in KS3.x, you have to do it manually..
Forum: support.WinUAE 11 September 2021, 22:27
Replies: 14
Views: 523
Posted By ross
This is the relevant code. I skip all the code...

This is the relevant code.
I skip all the code that setup ColdCapture vector and check for KS1.x.

ColdCapture_code
;fix 1MB chip on Ks1.3
bchg #1,$bfe001 ;cosmetic...
Forum: support.WinUAE 11 September 2021, 22:13
Replies: 14
Views: 523
Posted By ross
http://eab.abime.net/showpost.php?p=1500028&postco...

http://eab.abime.net/showpost.php?p=1500028&postcount=11
You can also solve the problem of KS1.x and 1MB chip-ram ;)
Forum: Coders. Asm / Hardware 11 September 2021, 22:08
Replies: 62
Views: 2,131
Posted By ross
So you want the system to rebuild execbase and...

So you want the system to rebuild execbase and company?
There are several ways (such as clearing the exec checksum).

But if you want to be brutal:
.v1x jsr _LVOSuperState(a6)...
Forum: support.WinUAE 11 September 2021, 21:56
Replies: 14
Views: 523
Posted By ross
It depends. With soft reset (CTRL-A-A or via...

It depends.

With soft reset (CTRL-A-A or via software), it doesn't clear the memory.
With the GUI and Reset button it clear the memory.
Forum: support.Hardware 11 September 2021, 21:41
Replies: 17
Views: 4,249
Posted By ross
HRM is wrong here, no doubt ;) At least for...

HRM is wrong here, no doubt ;)
At least for channels 2 and 3.
Channel 0 can go up to 29313Hz instead.

Maybe it made an average :D

EDIT:
I really tried to average (which obviously doesn't...
Forum: support.Hardware 11 September 2021, 19:43
Replies: 17
Views: 4,249
Posted By ross
Well, actually 28867 is the proper frequency for...

Well, actually 28867 is the proper frequency for a period of 124 in NTSC.
7159090/2/124=28867

So probably HRM report old value when only NTSC Amiga existed.

And also about the scanline length....
Showing results 1 to 40 of 3474

 
Forum Jump

All times are GMT +2. The time now is 23:17.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Page generated in 0.31996 seconds with 10 queries