Search found 166 matches

by Newbie
Thu Apr 19, 2018 2:41 pm
Forum: Official Reicast Discussion Forum
Topic: How make a CDI runnable on Reicast ?
Replies: 3
Views: 1302

Re: How make a CDI runnable on Reicast ?

Sorry for late answer ... tons of work to do :)

Well thanks for the script !
It does not solve the problem but it's certainly something on my code ...
The best thing to do is mock some things :)
What are you deving on?
A little framework very little thing ...
by Newbie
Sun Jan 28, 2018 4:04 am
Forum: Official Reicast Discussion Forum
Topic: How make a CDI runnable on Reicast ?
Replies: 3
Views: 1302

How make a CDI runnable on Reicast ?

Hi everybody, I make some code using KOS and want to test it on Reicast. I use common self boot tool like bootBreams and obtain a regular CDI file. But the file do not run on Reicast : it froze after the logo screen. The CDI produced is good and boot up on machine. I noticed that using Reicast some ...
by Newbie
Wed Sep 27, 2017 11:50 am
Forum: Programming Discussion
Topic: Writing some values in memory using assembly
Replies: 2
Views: 402

Re: Writing some values in memory using assembly

Well, replacing 0x8C0102B4 by 0xAC0102B4 in my code solves the issue. Dumping either from 0x8C0102B4 or 0xAC0102B4 locations gave the same consistent result. It is certainly, like you said, a data cache issue linked to the unknown behavior of serial upload tool about managing that. Thanks again :)
by Newbie
Sun Sep 24, 2017 9:37 am
Forum: Programming Discussion
Topic: Writing some values in memory using assembly
Replies: 2
Views: 402

Writing some values in memory using assembly

Hello everybody, I tried last week a code to compute some things and write result values sequentially using a loop to a field of bytes in main memory at a certain start address. At the very beginning the field of bytes is full of garbage values. After the code was uploaded via serial cable to Dreamc...
by Newbie
Sat Aug 19, 2017 6:07 pm
Forum: Programming Discussion
Topic: About floating point numbers and division instruction
Replies: 4
Views: 502

Re: About floating point numbers and division instruction

I would only add that floatundisf is a part of glibc.
All is said about this topic :)
Thanks.
by Newbie
Mon Aug 14, 2017 3:57 pm
Forum: Programming Discussion
Topic: About floating point numbers and division instruction
Replies: 4
Views: 502

Re: About floating point numbers and division instruction

Ok: thanks for reply :) First to load directly a constant floating point value like PI in a floating point register, the floating point value must be converted in the "IEEE754 Single precision 32-bit format" . There are some online converters and source code to do this. Then, simply hard code the va...
by Newbie
Fri Aug 11, 2017 4:07 pm
Forum: Programming Discussion
Topic: About floating point numbers and division instruction
Replies: 4
Views: 502

About floating point numbers and division instruction

Hi, I try to understand how division operations can be made on SH4. As I compile in "single mode", it will be float divisions not double. First, I try to de-compile some C code making division with different type of data. But assembly code is quite difficult to understand (even using 01 directive). ...
by Newbie
Wed Aug 02, 2017 6:10 pm
Forum: Programming Discussion
Topic: Equivalent to RTSC x86 indtruction on SH4
Replies: 6
Views: 628

Re: Equivalent to RTSC x86 indtruction on SH4

Thanks you very much, I will see this more closely.
I am every time amazed the number of things undocumented ...
by Newbie
Mon Jul 31, 2017 9:04 am
Forum: Programming Discussion
Topic: Equivalent to RTSC x86 indtruction on SH4
Replies: 6
Views: 628

Equivalent to RTSC x86 indtruction on SH4

Hi, On all X86 architecture, the Time Stamp Counter (TSC) is a 64-bit register counts the number of cycles since reset. It is used as a precise timer (a clock cycle delta). https://en.wikipedia.org/wiki/Time_Stamp_Counter Is there something that could be equivalent on SH4 architecture ? I need a tim...
by Newbie
Wed Jul 12, 2017 8:10 pm
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

Re: About GD Rom Drive reading a CD Rom

Well, I ask about a reading scenario sector with a specific number on a bootable DC disc (a two or more session disc) using KOS sector read function. First is the sector number a relative or absolute addressing number ? For example, if I ask for sector 14598, is it the 14599 th sector of the entire ...
by Newbie
Sun Jun 25, 2017 5:26 pm
Forum: Programming Discussion
Topic: About swapping disc / DC load serial
Replies: 2
Views: 328

Re: About swapping disc / DC load serial

I re burn my DC Load Serial disk and now it's fine !

Thanks
by Newbie
Sun Jun 25, 2017 5:22 pm
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

Re: About GD Rom Drive reading a CD Rom

Using CD ROM sector read function in KOS, is it possible to read all sector on the CD Rom ?
I try to read sector 0 to test but the function return me an error type SYSTEM ERROR (3).

Thanks for help
by Newbie
Fri Jun 23, 2017 6:30 pm
Forum: Programming Discussion
Topic: About swapping disc / DC load serial
Replies: 2
Views: 328

About swapping disc / DC load serial

Hi everybody, I have a little annoying thing : I use a CD ROM disc on my Dreamcast to boot with DC TOOL Serial. Then, sometimes, I need to change the disc (the DC Load boot one) with other disc (a data disc) to load data for testing purpose. But when I change the disc and close the lid, Dreamcast tr...
by Newbie
Wed Jun 21, 2017 5:35 pm
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

Re: About GD Rom Drive reading a CD Rom

Ok so some questions about CD Rom : Reading ECMA specifications, it seems that all datas are located in the "Program area". I see on Wikipedia that a 700 M Bytes / 80 Minutes CD ROM holds 360000 sectors. Are all those sectors located only in the Program area or is it located in a region starting fro...
by Newbie
Tue Jun 20, 2017 6:15 pm
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

Re: About GD Rom Drive reading a CD Rom

Thanks again.

I have some more questions but it will be only "CD Rom related" topic (not Dreamcast), is there a specific discussion room I can post in http://dcemulation.org or if not another forum web site ?

Thanks.
by Newbie
Tue Jun 20, 2017 7:54 am
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

Re: About GD Rom Drive reading a CD Rom

Thanks. Reading some articles about GD Rom structure, I have a question : It seems that on a GD Rom the sectors have the usual logical size (in bytes) but not the same length (in pits) depending the zone they are located in disc. So I want to know, in a regular CD Rom (80 minutes / 700 MB), are the ...
by Newbie
Mon Jun 19, 2017 6:41 pm
Forum: Programming Discussion
Topic: About GD Rom Drive reading a CD Rom
Replies: 10
Views: 856

About GD Rom Drive reading a CD Rom

Hi everybody, Some days ago, I start using KOS CD Rom access routines but a question "ring" my mind : GD Rom drive is CLV or CAV ? (I have seen contradictory information about that on the net). I have seen several time that GD Rom speed is 12X : - Is it always 12X ? - Is it the max value ? - Could i...
by Newbie
Tue Apr 11, 2017 8:09 am
Forum: Programming Discussion
Topic: The case of the divide by zero
Replies: 17
Views: 1098

Re: The case of the divide by zero

Thanks !
by Newbie
Wed Mar 29, 2017 7:57 am
Forum: Programming Discussion
Topic: The case of the divide by zero
Replies: 17
Views: 1098

Re: The case of the divide by zero

I think you need one more shift (shll) to set bit 15. shll8 shll2 shll2 shll2 moves 1 to position 14 At first, I shifted the bits correctly but when I executed the code, I saw the machine make a reset. I thought it was my fault and I had by error set a reserved bit (normally zero) in SR before maki...