ST Hardware Overscan

[JezC]

Hi, while "in between" projects (don't have any space to pick up a different project & waiting on getting my DVM back to diagnose the issue with my H5) I was wondering if there were any modern/available hardware overscan mods for the ST/STF(M) range?

I know they have been around in the past but I was wondering if there are any available now...

[Elliot]

I don't think so.

There are schematics about I believe if you want to re-create one. I am not sure how useful they are, very well behaved GEM stuff will be okay I guess but anything else will not work.

I am not sure but I also wonder if you will incur a speed decrement due to extra memory reads by the Shifter along with the extra screen memory the CPU will have to update - this is pure speculation.

What do you want to achieve? Is it a simple - look I have overscan?

[mrbombermillzy]

Hi Jez!

I remember at the show, I barely spoke to you, so I guess I at least owe you a chat!

Anyway, Im not sure what you require, regarding HW overscan (I wish @exxos had some sort of plug n play, either - ideally for me - a Megabus slot, or CPU socket overscan solution available in his store, but alas not).

If its for GEM use and you can spare a few wasted wait cycles then theres this extended vertical overscan program:

SCRPLUS2.zip

(1.08 KiB) Downloaded 1 time

*** The above is 'SCRPLUS2.PRG' but has had the .PRG extension changed to .zip for upload purposes.

Obviously horizontal overscan would be handy, but also far more costly in cycles.

Like Elliot says, theres also some schematics to build your own around.
Let me know if you cant find them and I will dig them out from my backup storage drive.

Anyway, HTH.

[exxos]

There are hacks in the old Atari hardware hacks site. I think you can cut DE to enable full screen but needed the driver to open a new desktop. Nothing I have ever done though.

[JezC]

Thanks all - I've found an old h/w hack for doing this but have also seen the auto overscan boards which look like a much neater solution! Shame no-one has them for sale still. I'd love a graphics card but the price is too might for me at the moment

I do want to use some extra screen area (for Cubase and some other Steinberg s/w - synth editors, Avalon) and might even have the system with at least a 16MHz accelerator so maybe the CPU overhead will be mitigated to some degree.

@mrbombermillzy I'll give that s/w a try (probably on my working H4 board in mono) & report back, thanks!

I too would love something on an easy to install basis (so I could move it between systems for testing) but maybe I'll have to follow up with the old original hacks & see from there.

[mrbombermillzy]

@mrbombermillzy I'll give that s/w a try (probably on my working H4 board in mono) & report back, thanks!

Im sorry. The linked program only works in low/med res! (Also it needs a certain mouse.prg in the auto folder if specifically using TOS v1.02. See here: https://github.com/ggnkua/Atari_ST_Sour ... h/scrplus2 ).

EDIT: Also, remember, weve been down this road before: viewtopic.php?f=50&t=5396

[troed]

I believe cheap version is to cut DE, connect composite to it, and then run Overscan or Lacescan. And yeah, you'd need a hardware-switch to control when to be in fullscreen and when not to.

[JezC]

Thanks @troed - I'll search for Lacescan as well (just in case).

With the shifter being socketed in the H4/H5, I should be able to do this without any non-reversible mods to the motherboard...

[JezC]

@mrbombermillzy I'll give that s/w a try (probably on my working H4 board in mono) & report back, thanks!

Im sorry. The linked program only works in low/med res! (Also it needs a certain mouse.prg in the auto folder if specifically using TOS v1.02. See here: https://github.com/ggnkua/Atari_ST_Sour ... h/scrplus2 ).

EDIT: Also, remember, weve been down this road before: viewtopic.php?f=50&t=5396

Ah, Ok...only issue with colour is that I still need to lift the pins on the video DAC on my H4 board, so it's rather bright...I'll re-read that thread to see how best to try it (maybe program up an EPROM 27C4096 with the supported version)...