The F18a DIY alternative with HDMI :)

[djones60]

28 minutes ago, lesbird said:

Hey David, have you tried on multiple monitors? I could not get a signal on my Samsung 32" TV so I switched to a HP 24" monitor with HDMI and it worked perfectly.

 

Les

 

Thanks for the idea.  Right now I have been trying it on a Sceptre TV.  Since I have an HP monitor, I will try that one first.  Then move on to one of the others like a Dell.

 

Update:  That was it.  It didn't like the Sceptre.  Ended up trying a generic TV that was more handy and the GW1NR-9C worked just fined on it   Got the F18 demo screen.  I see a soldering iron in my future for today.

 

Thanks

    David

 

Edited May 27, 2023 by djones60

[retrocanada76]

1 hour ago, lesbird said:

Hey David, have you tried on multiple monitors? I could not get a signal on my Samsung 32" TV so I switched to a HP 24" monitor with HDMI and it worked perfectly.

 

Les

 

Yes some TVs don’t like tang. Its not true hdmi but dvi

[lesbird]

So I fixed the problem with the F18A blacking out when I try to run some of the demos for my color graphics card on the Heathkit computer. Apparently trying to read from VRAM was the culprit. Commenting out one line of code in the KALEIDO.ASM fixed the problem. From the code I posted earlier I commented out the "IN VDP.DAT" line and that fixed the problem. See attached video.

 

*
*       READ VRAM DATA
*
RVD     MOV     A,L             LOW ADR
        OUT     VDP.CTL
        MOV     A,H             HIGH ADR
        ANI     77Q             MASK
        OUT     VDP.CTL
        NOP                     8 MS DELAY
        NOP
        NOP
        NOP
*       IN      VDP.DAT
        RET

 

So my question now is, is it possible to read VRAM data on the F18? I would think it would be. So it's quite possible something else isn't being set up properly for this code to work on the F18 clone.

 

[retrocanada76]

reading the vram should be supported, unless you have trace broken for the CSR line. check the continuity from the pin to the LVC245 and then from the LVC245 output to the tang.

[retrocanada76]

on your conde do you disable interrupts ? does the interrupt access the VDP  like reading vdp status ? IF so, you need to disable the VDP for the whole thing

 

[lesbird]

Yes, interrupts are disabled. I will check the CSR traces to the 245 and then from the 245 to the tang.

 

Les

 

[retrocanada76]

Here reading from vram

[lesbird]

Perfect, thank you. I checked the traces and they're all ok. I'll keep looking into it.

 

Les

 

[retrocanada76]

 

[+OLD CS1]

9118?

[craftsman1234]

5 hours ago, retrocanada76 said:

 

Just did the update for my NABU.   Mine show version 1.01 after the update.  Is that correct?

[retrocanada76]

It’s not not published yet. You need a new board, a new IC and to pullt the audio signal from somewhere. This aint’t software… 

[retrocanada76]

2 hours ago, OLD CS1 said:

9118?

I cannot use F18A. Get used to thst. It’s written in the f18a source licence conditions

[Hans23]

I think OLD CS1 wanted to point at the typo:  It is 9918, not 9118.

[retrocanada76]

38 minutes ago, Hans23 said:

I think OLD CS1 wanted to point at the typo:  It is 9918, not 9118.

Ah yes, well there is in fact a 9118 hehe. 

[retrocanada76]

So the version 2.0 will be made of 2 boards: a tiny small socket that allows a flat cable going left or right:

 

 

and the board itself allowing being connected left or right:

 

 

So you can place it anywhere inside de case with the HDMI connector pointing any direction you need.

 

There are two extra signals coming to the socket: audio and mode1 (address 1) this mode 1 is not used for the VDP9918. It has a future use.

 

 

 

[craftsman1234]

4 hours ago, retrocanada76 said:

It’s not not published yet. You need a new board, a new IC and to pullt the audio signal from somewhere. This aint’t software… 

Interesting so what is version 1.01?   Just a new Tang boot up screen and rename?

[retrocanada76]

2 hours ago, craftsman1234 said:

Interesting so what is version 1.01?   Just a new Tang boot up screen and rename?

yup. rebranding. i can't name it f18a.

[Duewester]

5 hours ago, retrocanada76 said:

So the version 2.0 will be made of 2 boards: a tiny small socket that allows a flat cable going left or right:

 

 

and the board itself allowing being connected left or right:

 

 

So you can place it anywhere inside de case with the HDMI connector pointing any direction you need.

 

There are two extra signals coming to the socket: audio and mode1 (address 1) this mode 1 is not used for the VDP9918. It has a future use.

 

 

 

Great news. I have one Tang and one Ti left to upgrade.

[+OLD CS1]

8 hours ago, retrocanada76 said:

Ah yes, well there is in fact a 9118 hehe. 

The 9118 is a later derivative of the 9918, which uses different memory, otherwise the same VDP.  Just pedantry.  Could call it the 9218 and get away with it, too.

[Hans23]

I've replaced the F18A in one of my TI-99/4A's with the SMD based tn-vdp, and things fit perfectly:

 

I used a short pigtail to externalize the HDMI output.  Its cable is a bit too stiff for my taste, but it fit in.  To mount the HDMI output in the back, I cut away four of the plastic fins - Luckily, these four are only connected to the body on one side so removing them was easy.  Then I drilled between two neighboring fins to make space for the screw.

 

[Duewester]

7 hours ago, Hans23 said:

I've replaced the F18A in one of my TI-99/4A's with the SMD based tn-vdp, and things fit perfectly:

 

I used a short pigtail to externalize the HDMI output.  Its cable is a bit too stiff for my taste, but it fit in.  To mount the HDMI output in the back, I cut away four of the plastic fins - Luckily, these four are only connected to the body on one side so removing them was easy.  Then I drilled between two neighboring fins to make space for the screw.

 

@Hans23Are you using the RF Shield?

[Hans23]

3 hours ago, Duewester said:

Are you using the RF Shield?

With this machine, I do not and I generally remove RF shields from all of my systems.  I've just received another TI-99/4A console which I'm planning to equip with a HDMI only tn-vdp, and I'll try to leave the RF shield in place just for the fun of it.  Routing the HDMI cable out will be annoying, but maybe I can get it done.  Will report.

[Duewester]

@Hans23, do you put a heat sink on the 9904? One of my Ti's came with a heat sink next to the little dimple for the clock crystal for the 9904. The one I have open now doesn't have a heat sink but the 9904 looks newer (looks like an 87 date code)than most of the other chips. I just wonder if the lack of heat dissipation contributed to the failure of the original.

Just wonderin.

[Hans23]

The 9904 gets pretty hot, but with the RF shield removed, the convection inside of the console is much better.  I did not have any issues caused by overheating in my consoles, but I'm also not operating them for stretches of days.  Adding individual heat sinks don't hurt, though.

Edited June 3, 2023 by Hans23