Improving signal strength on Superboard II

[Sideburn]

Yeah everything looks ok. I even changed the clock. It’s all back in this thread earlier.

[ronin47]

Yeah everything looks ok. I even changed the clock. It’s all back in this thread earlier.

Definitely odd.

[Sideburn]

Yeah, it's nice and bright a voltages and frequencies look good and within spec. Your board is a replica though right? with more modern components?

[bxdanny]

Sideburn,

I thought you were getting a stable display on the new monitor. Was I wrong? Is it not as stable as you thought at first? Or are you simply referring to the problems you had with other monitors?

[Sideburn]

Sideburn,

I thought you were getting a stable display on the new monitor. Was I wrong? Is it not as stable as you thought at first? Or are you simply referring to the problems you had with other monitors?

I was referring to the "new" (amazon/modermn) displays like the one ronin47 just got that is working for him. my old ebay 9" is working good. I still need to tweak the eprom and see if that fixes there clipping but other than that its good so far.

[ronin47]

Yeah, it's nice and bright a voltages and frequencies look good and within spec. Your board is a replica though right? with more modern components?

Yes, mine is one of the Klyball boards.

I expect that the modern IC's are somewhat better made, though I had a problem of a very flickery display, and I swapped U21 for a 7404 rather than a 74LS04 that was in the BoM, and it fixed it, so components, their manufacture date and type definitely play a part.

[Sideburn]

That does look good, the monitor seems to be the same width as the keyboard. But the last (48th) character seems to have its right edge cut off, and as there is more than one character width of blank margin on the left, you might want to decrease the value at $FFE0 by one [more].

When you mentioned wanting to add a speaker, I thought (I guess because I had just seen dave's comments to nama about sound from his keyboard) that perhaps you might also want to be able to play the "noise" output from J4. But since you don't have that section populated (it usually wasn't on the 600B), I guess there'd be no point, especially since it takes careful machine-language programming to make that sound like anything other than, well, noise.

I went to tackle this clipping issue today but I am struggling trying to find $FFE0 location to change the value.
I don't see it in XgPro or my hex editor. But i barely know what I am doing.

I am looking at the syn600-48c2k.rom you game me.

Do you mean the 00 D2 at 000000E0 ?

E0.jpg (28.68 KiB) Viewed 181 times

Thnx,

-Tavis

[bxdanny]

The 8D shown at location 992 (which is $3E0) would be the location in question. At least if you have pin 19 of the ROM pulled low. I'm not sure if you have it reattached to the A10 line, or still pulled high or low, so unless you have it pulled low, it would really be location 2016 ($7E0) that you want to change.

[Sideburn]

I’m pulling it high at the jumper pads on the board.

IMG_8178.jpeg (504.9 KiB) Viewed 180 times

A I’ve tied pin 24 and 21 together.

[Sideburn]

The 8D shown at location 992 (which is $3E0) would be the location in question. At least if you have pin 19 of the ROM pulled low. I'm not sure if you have it reattached to the A10 line, or still pulled high or low, so unless you have it pulled low, it would really be location 2016 ($7E0) that you want to change.

Ok so since I am pulling pin 19 high, I will change location 2016 from 8D to 7D. That correct?

change:

8d.jpg (35.92 KiB) Viewed 176 times

to:

7d.jpg (45.36 KiB) Viewed 176 times