RiscOS 2, A420/1 and Zarch

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trixster
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RiscOS 2, A420/1 and Zarch

Postby trixster » Tue May 09, 2017 8:57 pm

Hi all,

I've just received an A420/1 which has riscos 2. Naturally I want to play Zarch on it!

If I set LK1 to north, LK2 to closed and set *configure monitortype 3, my LCD monitor (a dell 2001fp) will display the desktop in mode 27 640x480x16 nicely. Zarch will not load however, saying it has not enough memory. Screen memory in mode 27 is 160k.

The game loads fine though if I *configure monitortype 1 (screen memory here is 80k) but whilst the display looks great and the monitor can handle it, it's quite a squashed screen and the monitor will not remember settings after a reset (it behaves the same way with 15khz amigas).

So is there anyway to get Zarch to load with monitortype 3 (ie vga) in riscos 2?

Also, am I right in thinking that riscos 2 not have a monitortype auto like riscos 3 does? If I type that I get an error.

Thanks!
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + RPi2 CoPro | A420/1
BBC Master Turbo + DC | Atom | A1200 + 80Mhz 060 | A500 | Jaguar
A4000/040 + 66Mhz 060 | Atari Falcon | Saturn | PS1 | SNES | CPC6128 | C64 | 3DO

sirbod
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Re: RiscOS 2, A420/1 and Zarch

Postby sirbod » Wed May 10, 2017 1:57 pm


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trixster
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Re: RiscOS 2, A420/1 and Zarch

Postby trixster » Wed May 10, 2017 2:39 pm

I'm sure I tried that yesterday evening and it said it only runs on riscos 3 machines.
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + RPi2 CoPro | A420/1
BBC Master Turbo + DC | Atom | A1200 + 80Mhz 060 | A500 | Jaguar
A4000/040 + 66Mhz 060 | Atari Falcon | Saturn | PS1 | SNES | CPC6128 | C64 | 3DO

steve3000
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Re: RiscOS 2, A420/1 and Zarch

Postby steve3000 » Wed May 10, 2017 6:32 pm

trixster wrote:I'm sure I tried that yesterday evening and it said it only runs on riscos 3 machines.

Probably because I didn't have a RO2 machine when I wrote it.

Problem is that VGA monitors weren't that common in 1988 and nor was the thought of running games in VGA compatible modes. So RISC OS 2 has no built in VGA equivalents of MODE 9 or 13 - the usual game modes... And LCDgamemodes works by patching the built-in VGA equivalent of modes 9 and 13 under RISC OS 3.

So to get it working under RO2, we'd need a second module to provide those VGA modes.

If you're keeping your computer running RO2, and willing to test, I can send you a test module at the weekend?

Other solution of course would be to try a SCART compatible TV and SCART cable? Unless your monitor accepts TV resolution signal (50Hz vsync and 15KHz line rate)?

steve3000
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Re: RiscOS 2, A420/1 and Zarch

Postby steve3000 » Wed May 10, 2017 6:37 pm

I knew I'd read about that Dell monitor before... You posted about it:

trixster wrote:I use two Dell 2001fp lcds and a Viewsonic VP2030b. The Dells have dvi vga svideo and composite in. They sync at 15khz and do smooth 50hz scrolling on dvi, vga and svideo for all the machines.


If it does accept 15KHz, try monitor type 1 or 0. You may need to adjust the sync. But that should provide perfectly usable TV resolution RISC OS 2.

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trixster
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Re: RiscOS 2, A420/1 and Zarch

Postby trixster » Wed May 10, 2017 7:11 pm

steve3000 wrote:
trixster wrote:I'm sure I tried that yesterday evening and it said it only runs on riscos 3 machines.

Probably because I didn't have a RO2 machine when I wrote it.

Problem is that VGA monitors weren't that common in 1988 and nor was the thought of running games in VGA compatible modes. So RISC OS 2 has no built in VGA equivalents of MODE 9 or 13 - the usual game modes... And LCDgamemodes works by patching the built-in VGA equivalent of modes 9 and 13 under RISC OS 3.

So to get it working under RO2, we'd need a second module to provide those VGA modes.

If you're keeping your computer running RO2, and willing to test, I can send you a test module at the weekend?

Other solution of course would be to try a SCART compatible TV and SCART cable? Unless your monitor accepts TV resolution signal (50Hz vsync and 15KHz line rate)?


Hi Steve, thanks for the reply. Yes I'm planning to keep it as a riscoos 2 machine so a test module would be excellent!
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + RPi2 CoPro | A420/1
BBC Master Turbo + DC | Atom | A1200 + 80Mhz 060 | A500 | Jaguar
A4000/040 + 66Mhz 060 | Atari Falcon | Saturn | PS1 | SNES | CPC6128 | C64 | 3DO

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trixster
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Location: York

Re: RiscOS 2, A420/1 and Zarch

Postby trixster » Wed May 10, 2017 7:13 pm

steve3000 wrote:I knew I'd read about that Dell monitor before... You posted about it:

trixster wrote:I use two Dell 2001fp lcds and a Viewsonic VP2030b. The Dells have dvi vga svideo and composite in. They sync at 15khz and do smooth 50hz scrolling on dvi, vga and svideo for all the machines.


If it does accept 15KHz, try monitor type 1 or 0. You may need to adjust the sync. But that should provide perfectly usable TV resolution RISC OS 2.


Yeah it works with 15khz modes but the monitor doesn't remember the posn of the screen after each reset/power cycle so you have to manually Centre it each time you switch on, which is a bit annoying!
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + RPi2 CoPro | A420/1
BBC Master Turbo + DC | Atom | A1200 + 80Mhz 060 | A500 | Jaguar
A4000/040 + 66Mhz 060 | Atari Falcon | Saturn | PS1 | SNES | CPC6128 | C64 | 3DO

steve3000
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Re: RiscOS 2, A420/1 and Zarch

Postby steve3000 » Tue May 30, 2017 12:55 pm

trixster wrote:Yes I'm planning to keep it as a riscoos 2 machine so a test module would be excellent!

...A few weekends later and here is a test module for RISC OS 2. :)

This module won't fix Zarch, but I'm interested to know if these modes work under RISC OS 2, on your monitor - then I can work on adapting the module to patch the RISC OS 2 default modes.

The attached module provides new modes 64-79, 89-95 and 105-113. These should be identical to RISC OS 3 SVGA/VGA versions of modes 0-15, 25-31 and 41-49 (the MODE numbers are the original mode number+64).

Note: MODEs 29-31 (93-95 in this module) are SVGA only and require a 36MHz clock feed into VIDC (so unless you have a manual VIDC enhancer, these won't work). As with RISC OS 3, the other modes are designed for 25.175MHz but should work with the standard 24MHz clock, depending your monitor.

Let me know how you get on.
Attachments
TESTRO2.zip
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trixster
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Re: RiscOS 2, A420/1 and Zarch

Postby trixster » Thu Jun 01, 2017 9:32 am

Hi Steve,

Thank you for this, I'll try and give it a whirl this weekend when the otherhalf is away!
A3020 | A3000 | BBC B + 128K RAM/ROM + 20K Shadow + RPi2 CoPro | A420/1
BBC Master Turbo + DC | Atom | A1200 + 80Mhz 060 | A500 | Jaguar
A4000/040 + 66Mhz 060 | Atari Falcon | Saturn | PS1 | SNES | CPC6128 | C64 | 3DO


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