Online image converter, can it be used for the Geneve?

[Nick99]

Here it is:

 

http://msx.jannone.org/

 

It´s an image converter for MSX and produces an VRAM dump, is it possible to use the VRAM dump on the Geneve or the TI-99/4a with a V9938?

Edited May 27, 2018 by Nick99

[+mizapf]

If someone writes a converter to a known graphic format, this should be possible. See https://www.ninerpedia.org/wiki/Graphic_file_formats

[+9640News]

MDOS as I recall allows you to do a dump through the DSR XOP of VRAM to disk. Just give it starting address and length, and you can save the memory. You can also "load" the dump back into vram.

 

Beery

[+mizapf]

OT: Why do I frequently see a broken image link for your avatar? (The same happens with RXB.) When trying to display your avatar, I am directed to your F*book profile with an empty screen (lookaside...).

 

I am blocking some FB links in my browser, but even when I turn it off it does not help. At other times I can see your profile pic again. Maybe it would be better to upload a separate image to AtariAge without linking to FB.

[+9640News]

OT: Why do I frequently see a broken image link for your avatar? (The same happens with RXB.) When trying to display your avatar, I am directed to your F*book profile with an empty screen (lookaside...).

 

I am blocking some FB links in my browser, but even when I turn it off it does not help. At other times I can see your profile pic again. Maybe it would be better to upload a separate image to AtariAge without linking to FB.

 

First time I have seen the broken link. I did upload an image to resolve the issue.

 

Thanks for the head's up.

​Beery

[+OLD CS1]

OT: Why do I frequently see a broken image link for your avatar? (The same happens with RXB.) When trying to display your avatar, I am directed to your F*book profile with an empty screen (lookaside...).

 

I am blocking some FB links in my browser, but even when I turn it off it does not help. At other times I can see your profile pic again. Maybe it would be better to upload a separate image to AtariAge without linking to FB.

 

FWIW, I do everything I can to avoid touching anything Facebook. I have instituted some FB blocks in my system, some that are deep or obfuscated enough that I can no longer find them. They are quite effective but mean I have the same problem with avatars as you.

[artrag]

MDOS as I recall allows you to do a dump through the DSR XOP of VRAM to disk. Just give it starting address and length, and you can save the memory. You can also "load" the dump back into vram.

 

Beery

The msx files are vram dumps with a header of 7 bytes. Skip the header and load the data where you like.

[Nick99]

The msx files are vram dumps with a header of 7 bytes. Skip the header and load the data where you like.

 

 

That sounds good like good news... but for me there is just one problem, I don´t remember much of how to do things like this after 24 years with no use of my Ti or Geneve computer.

I can assure you that I feel like a total beginner in some areas...

[+9640News]

On the Geneve, all you need to do is get hold of the GenREF package. The PDF's are at http://9640news.ddns.net:8080/. That will give you the necessary information on how to use the LOAD command in the DSR XOP for MDOS.

 

With the 7 byte header of the MSX file, I am not sure what the best way to deal with that may be. I'm guessing it may be simpler to load the image into CPU ram, then move the bytes into VRAM as that header will create an issue I do not think you can offset on the LOAD process to put it straight into VDP.

One thing is missing if you want to display properly whatever is in VRAM. One will need to know what the VDP registers should be preset too for when the MSX VRAM dump was made. I do not know if there is a default setting common to all the MSX dumps, or if the 7 byte header someone eluded too contains information/references to the settings that should be used.

 

Just so you do not get scared about the coding, MDOS code using the XOP's for a CPU to VDP transfer would involve some coding like the following:

 

This is for assembly code:

 

1. Reserve Program memory space (8K) plus 128K additional CPU ram via XOP (5 lines code).

2. Get Pagetable (5 lines code)

3. Call routine to set VDP registers (10 to 15 lines of code depending upon if Register content is in data/byte statements).

4. Call DSR XOP referencing the PAB (3 lines code)

5. Move CPU ram to VDP ram with CPU paging (10 or so lines of code).

6. Observe display

7. Scan keyboard for keypress using XOP ( 5 lines code) .

8. Exit (BLWP @0).

 

That is the simplest way with the PAB already defined with filename/location path. More bells and whistles like retrieving filename from command line or typing in a filename/path add more code.

 

To do the same thing on a TI-99/4A or under GPL mode with a 9938/9958 would require a lot more code with respect to loading the file as you would probably do sector or record reads. It was always so much easier to do things for me under MDOS. It would probably be simpler in c99 or maybe even Forth. Maybe I have just given our Forth guru an opportunity for an app?????

 

Beery

[artrag]

On MSX the presets are quite simple, here in the following those for the most common screen modes

 

Screen 2 (TMS9918 "bitmap" mode)

 

Tile definitions: 0000h (256*8*3)

Tile colors: 2000h (256*8*3)

Name Table 1800h (32x24)

 

Screen 5

bitmap data: 0000h (128*212)

 

Screen 6

bitmap data: 0000h (128*212)

Screen 7

bitmap data: 0000h (256*212)

Screen 8

bitmap data: 0000h (256*212)

[+9640News]

But how do you know which mode is which? Is it in the 7 byte header?

[artrag]

No, you have to know it by your own

 

The 7 bytes in the header mean this:

byte 0 : ID byte #FE
bytes 1,2: start-address in RAM or VRAM
bytes 3,4: end-address in RAM or VRAM
bytes 5,6: execution-address (non zero only for executable files loaded in RAM)

 

This because BIN files are used in MSX basic also for executable programs

 

You can assume that:

 

16KB are mainly screen 2,

32KB are mainly screen 5

64KB can be both screen 7 and screen 8