Jump to content
IGNORED

F18A mod info?


digdugnate

Recommended Posts

Good afternoon all!

 

I have been reading about the F18A video mod for the TI, and it's piqued my interest- VGA out, non-flickering sprites? Yes please!

 

I would like to read some more information on it, though, so could someone point me towards good comprehensive documentation on how it's installed/etc?

 

I can Google, but thought that someone on the forum would provide better information.

Link to comment
Share on other sites

codehackcreate.com has all the info, take out 9918a chip, insert f18a and stick ribbon cable out the back and hook to vga, your sounds still come out the regular din port

vga graphics, fixes sprite bug, allows for enhanced games like super mario bros demo

 

http://atariage.com/forums/topic/168968-f18a/?view=findpost&p=3245944&hl=f18a

http://atariage.com/forums/topic/207586-f18a-programming-info-and-resources/?view=findpost&p=3728749&hl=%2Bf18a

 

Greg

  • Like 1
Link to comment
Share on other sites

The F18A provides so much more than just VGA output and flicker free sprites. Here is a summary:

 

1) Colors
Colors can be redefined with 16 different values for red, green, and blue - in total 4096 different colors. And programs have 4 palettes of 16 colors to choose from.
2) Multicolor character patterns
Characters can have 2, 4 or 8 colors. They can be mirrored in both x and y.
3) Bitmap layer
On the optional bitmap layer pixels can be colored individually in either 4 or 16 colors. The 16 color pixels are twice as wide as normal pixels.
4) Multicolor sprites
Sprites can have 2, 4 or 8 colors (including the transparent background color). They can be mirrored in both x and y, and linked. The number of possible sprites on a line can be defined from 1 to 32.
5) Second character layer
Another layer of characters with 2, 4, or 8 colors and an optional transparent component can be displayed on top of or beneath the sprite layer.
6) Hardware scrolling
The F18A has hardware support for smooth scrolling in all directions, individually for each character layer.
7) 80 columns text mode
The 80 column mode is compatible with the 9938/9958 (except for the limited RAM) and with optional individual coloring (foreground/background) of each character.
8 ) GPU: A 100 MHz CPU is built into the F18A that runs in parallel with the normal CPU and can address video memory only, i.e. it cannot control disk, keyboard/joystick, sound, etc. The GPU is for most parts compatible with the TMS9900 instruction set.
9) Scanline interrupts
The GPU and/or the CPU can execute code when a scanline has been drawn.
Note that there is still only 16K video RAM available. Characters or sprites with 4 colors take twice as much memory as those with 2 colors. 8 colors take 3 times as much RAM. A bitmap layer covering the whole screen takes 12K. So even though there are many colors available, the F18A does not provide any full screen high color bitmap modes.
  • Like 4
Link to comment
Share on other sites

codehackcreate.com has all the info, take out 9918a chip, insert f18a and stick ribbon cable out the back and hook to vga, your sounds still come out the regular din port

vga graphics, fixes sprite bug, allows for enhanced games like super mario bros demo

 

http://atariage.com/forums/topic/168968-f18a/?view=findpost&p=3245944&hl=f18a

http://atariage.com/forums/topic/207586-f18a-programming-info-and-resources/?view=findpost&p=3728749&hl=%2Bf18a

 

Greg

thanks! i've been going through their docs on it. fascinating stuff!

Link to comment
Share on other sites

 

The F18A provides so much more than just VGA output and flicker free sprites. Here is a summary:

 

1) Colors
Colors can be redefined with 16 different values for red, green, and blue - in total 4096 different colors. And programs have 4 palettes of 16 colors to choose from.
2) Multicolor character patterns
Characters can have 2, 4 or 8 colors. They can be mirrored in both x and y.
3) Bitmap layer
On the optional bitmap layer pixels can be colored individually in either 4 or 16 colors. The 16 color pixels are twice as wide as normal pixels.
4) Multicolor sprites
Sprites can have 2, 4 or 8 colors (including the transparent background color). They can be mirrored in both x and y, and linked. The number of possible sprites on a line can be defined from 1 to 32.
5) Second character layer
Another layer of characters with 2, 4, or 8 colors and an optional transparent component can be displayed on top of or beneath the sprite layer.
6) Hardware scrolling
The F18A has hardware support for smooth scrolling in all directions, individually for each character layer.
7) 80 columns text mode
The 80 column mode is compatible with the 9938/9958 (except for the missing RAM) and with optional individual coloring (foreground/background) of each character.
8 ) GPU: A 100 MHz CPU is built into the F18A that runs in parallel with the normal CPU and can address video memory only, i.e. it cannot control disk, keyboard/joystick, sound, etc. The GPU is for most parts compatible with the TMS9900 instruction set.
9) Scanline interrupts
The GPU and/or the CPU can perform code when a scanline has been drawn.
Note that there is still only 16K video RAM available. Characters or sprites with 4 colors take twice as much memory as those with 2 colors. 8 colors take 3 times as much RAM. A bitmap layer covering the whole screen takes 12K. So even though there are many colors available, the F18A does not provide any full screen high color bitmap modes.

 

 

You know when i get SAMS RXB done and released it will free up 447 bytes of VDP memory (pointers and temp storage) and remove all strings, symbols and VDP stack from VDP, all moved to SAMS RAM.

 

Of course this requires a P-Box with a SAMS card, or a SAMS version not built yet stand alone or internal card like the F18.

 

Now that would be very cool a 1meg RAM SAMS and F18 in just a console. Anyway by next year this SAMS RXB project should be complete.

Edited by RXB
Link to comment
Share on other sites

this is all super cool info. i have a couple of consoles that i can 'experiment' on so i might pick up an F18A (hornet, hehe) board. i'm not *quite* ready to do something like that on my mostly-pristine silver and black one yet. :)

 

mmm, brushed aluminum..... /homerdrool

  • Like 2
Link to comment
Share on other sites

Installing the F18A into the 99/4A is pretty easy since the original 9918A VDP is already in a socket. The hardest part is disassembling the console and modding the case for the VGA header. If you search this sub-forum you will find threads where people have posted their F18A installs. Admittedly I have little modding / install info on my website, but I'm planning on correcting that. For now the best place to get help, suggestions, info, etc. is here in the forum.

 

Also, I don't feel right pushing my own creations in the forum, so once again *Thank You* to everyone here for the advocacy and kind comments about the F18A. It is this kind of appreciation that is the biggest reward and motivation for doing these kinds of projects.

  • Like 5
Link to comment
Share on other sites

Installing the F18A into the 99/4A is pretty easy since the original 9918A VDP is already in a socket. The hardest part is disassembling the console and modding the case for the VGA header. If you search this sub-forum you will find threads where people have posted their F18A installs. Admittedly I have little modding / install info on my website, but I'm planning on correcting that. For now the best place to get help, suggestions, info, etc. is here in the forum.

 

Also, I don't feel right pushing my own creations in the forum, so once again *Thank You* to everyone here for the advocacy and kind comments about the F18A. It is this kind of appreciation that is the biggest reward and motivation for doing these kinds of projects.

 

 

Thank you as well Matthew. I actually ordered mine last night (my name is Bruce, order 520) as it looks like a fantastic piece of kit and I keep seeing the quantity left on your website decreasing ;)

Edited by eightbit
  • Like 2
Link to comment
Share on other sites

just.. have.. to. wait.. a couple.. of weeks....

 

(aggro from my household budgetkeeper. ;) i've bought quite enough TI stuff for a bit.)

 

Ah c'mon...If you're going to have a vintage computer hobby, you have to grow a thick skin against the icy stares, stern looks, angered glances and hours (days, weeks?) of stone cold silence!

 

YOU have to live with the knowledge that any day you could arrive home to find the "budgetkeeper" sitting at the dining room table with a newly arrived USPS delivery and a "I thought we had talked about this" look.

 

And after all, what is more important??? Your toys, or your continued financial health? (In my case, it's between my toys and my continued GENERAL health, since she's way bigger than me, but at least being Canadian, we have universal health care, so my injuries don't eat into my TI budget)

  • Like 3
Link to comment
Share on other sites

Advice needed; I've installed my new F18A and I am amazed how well it looks. My question is now how to get just the audio out? I still have the RF Modulator that came with the computer if I need to hack into that. What I would like to do is connect it to the audio jack on my speakers. How are you getting the audio out after you have installed the F18A?

 

Let me add that I have the RF Modulator connected to a TV but no sound.

Edited by randalrand
  • Like 1
Link to comment
Share on other sites

Advice needed; I've installed my new F18A and I am amazed how well it looks. My question is now how to get just the audio out?

 

You can grab a 3.5mm mono or stereo jack cheap from your local electronics store (TI audio out is mono). In wiring the 3.5mm jack, solder two short pieces of wire to it (pin and ring), long enough to allow you to mount it to the back of the case, then solder the two wires to grab audio out (pin 3) and ground (pin 5) from the old DIN video out connector - Pic 1.

 

I'm actually got a project in the works trying to mod back to a 99/4 concept with a small internal 8 ohm speaker, amp, and volume slider outputting to a little more expensive 3.5mm jack that "disables" the internal speaker when an external 3.5mm cable is plugged in. I found a small DIY audio amp on ebay http://www.ebay.com/itm/291947391697 (temporarily mounted right now until I can move the board closer to the where the DIN used to be and install the volume slider and audio out jack.

 

Hope that gives you some ideas.

post-48993-0-90792500-1493589492_thumb.jpg

post-48993-0-47593700-1493589516_thumb.jpg

post-48993-0-58404400-1493589539_thumb.jpg

Link to comment
Share on other sites

Based upon your advice I dug around my garage to find my old (non-working) C64. To my delight I found it, inside were the cables and found that the C64 already had a DIN connector, exactly like the TI, with a composite video and audio plug. No further out of pocket expense and it works beautifully. Thanks again all.

Link to comment
Share on other sites

Based upon your advice I dug around my garage to find my old (non-working) C64. To my delight I found it, inside were the cables and found that the C64 already had a DIN connector, exactly like the TI, with a composite video and audio plug. No further out of pocket expense and it works beautifully. Thanks again all.

 

Yes, as you can see in the graph I attached, TI (NTSC) C64 and Atari 800 can use the same DIN-5 cable for AV (composite) connection.

Link to comment
Share on other sites

 

Probably yes. If it uses the standard EU audio pins, 2 is ground, and 3/5 are left/right output channels (and 1/4 are the input ones in a tape interface), so in the TI case, in pin 5 you'll have no signal and in pin 3 you'll have audio.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...