How to Use an A2320

[raoulduke]

Hey, I'm very new to Amiga and there are aspects of it I find confusing.  After reading the manual I think, but am not sure, that an A2320 card if working should just output to a monitor.  Mine does not (with the bypass switch in either direction).  I haven't bothered with fine tuning but is it broken or am I missing something (a la drivers etc.)

I haven't tried it with WB fully booted, so if it does need drivers it's possible/probable they're installed.

[I'm really concerned about trying to reformat and reinstall because the machine won't seem to boot from a floppy with my Great Valley SCSI card for some reason (or bc of the memory on it, not sure).]

[Effy]

Think the A2320 was limited to 16 colours only, so it may appear faulty when you plug it into an A4000 with 256 colours enabled ... doesn't it even show screen when you boot with two mouse buttons down

[guest11527]

Hey, I'm very new to Amiga and there are aspects of it I find confusing.  After reading the manual I think, but am not sure, that an A2320 card if working should just output to a monitor.

The A2320 does not require any software installation. As soon as it is installed in the RGB slot (you put it there, right? It does not go into the Zorro slots) it should give you a picture. Probably not ideal, but at least a 31kHz signal your average VGA monitor should be able to display.

Is the cart really fit tightly into the slot? Try to push it down firmly.

Just one additional note: While the card doubles the horizontal frequency from 15kHz to 31kHz, it does not change the vertical scan frequency. In specific, the average VGA monitor will not sync down to 50Hz (PAL), so you'd probably want to change that to NTSC (60Hz) in the early startup menu. Hold down both mouse buttons while turning the machine on, press space.  Greetings, Thomas

[raoulduke]

Forgetting the port, which idk how to debug with no obvious output, will the card working/not working affect my video memory count?  The A2320 has 384k? How much should show up normally on an A2000 Rev. 4.4?

[midway]

The A2320 is supposed to be used with ECS or OCS Amigas only.
It displays all of these modes normally. That's including HAM interlaced (4096 colors)
 Its not a graphics card, doesn't matter how much buffer it has, it wont show up. What you see is Chip Ram. 512 KB for your Amiga 2000.

[Oldsmobile_Mike]

Check in early startup, or maybe with a program like Scout or SysInfo, is the card detected?  (not sure if video slot is scanned by those utilities)

[Matt_H]

@ Oldsmobile_Mike

I don't believe the video slot contents can be detected by anything.


@ raoulduke

To expand upon what others have said, the 2320 is intended for the A2000 and no drivers are required - plug it in and it should work. If you have a PAL (European) machine and you are using a modern LCD monitor, you may have problems. Most LCDs can only sync to 56Hz vertical refresh and PAL is 50Hz vertical refresh. Some LCDs can handle 50Hz - try to find one of those or an older CRT display to test.

But to back up a step, can you confirm that the Amiga is working (read: booting up) at all? There's a black and white composite video port on the A2000, which is handy for diagnosing basic signs of life.

[raoulduke]

Yeah the machine works great... after I destroyed and rebuilt it.  I'm using a 520 adapter with the video out to a large lcd television; the mono output also works.  I think I've run down the manual for my monitor which says that it'll work at 31.5khz with 640x480.  The monitor itself reads a signal (but stays on standby) but there's no actual display.  The card is in the proper socket.  I took it out and put it back in but I haven't done much else including popping the ROM.  I'm replacing the HD at the moment.

[raoulduke]

So the skinny is this: On my Dell 1704FPS monitor in analog mode, with the bypass away from the fan, which I think is off, the monitor oscillates between green power light, meaning either power or signal - not sure, and orange power light standby mode.  When it goes to green there's backlighting but no picture.  The same test on my large LCD television shows no signal.  

I thought I'd read I was looking for one that supports 31.5khz, but so should I be looking for an old (like mid-90s branded) CRT or a just older-than-mine LCD...?  I'd really rather not use a CRT; but if I have to pay $5 to definitively test the card I will.

Whether or not the utilities you suggested would work I haven't figured out how to transfer files and it just occurred to me that when GVP Utilities accidentally wiped my Zip Drive backup I lost PC Utils; so I'll have to grab it off the original HD again.

[raoulduke]

Actually there is a test disk: http://amiga.resource.cx/install/A2320-12.dms  (*Actually it may just be the flicker test disk...)

And actually instead of the $5 for a CRT; maybe I'll just get the Amiga display to VGA cable.  Is there some reason that would be inferior?

[Oldsmobile_Mike]

And actually instead of the $5 for a CRT; maybe I'll just get the Amiga display to VGA cable.  Is there some reason that would be inferior?

If you're talking about just converting the 23-pin output to a 15-pin (VGA style connector), this isn't the same as scan doubling to 31Khz. It will only be 15Khz. Very few modern monitors will support it (and only a few screenmodes).

If you want to display native Amiga output on a modern monitor, why not just get an Indivision?

[guest11527]

Check in early startup, or maybe with a program like Scout or SysInfo, is the card detected?  

No chance. The video port does not participate in the autoconfig detection, and there is also no hardware logic that allows software to check whether a card is plugged into the video port or not.

The most likely problem of the OP is that the monitor does not synchronize to the frequency of the scan doubler. It is a 31kHz signal, but possibly a 50Hz vertical scan frequency the monitor does not pick up. It is neither 100% VGA compliant (i.e. even the scan-doubled NTSC signal of a 640x200 - then 640x400 - frame does not exactly conform to VGA).

[midway]

I had an issue once with an A2320 and a TFT. I needed to use the calibration device forgot the name of it in English sorry (a little part at the back of the card were you can use a (grounded/shielded) screwdriver turning clock or counterclockwise with the Amiga running and open (so be careful) and a CRT first to see the picture staying in sync. I had to borrow one from a friend, after that it worked fine with my TFT

[Matt_H]

@ raoulduke

In the old days, the issue for Amigas was finding a monitor capable of displaying 15KHz horizontal, or scandoubling the Amiga's display to 31KHz horizontal. Nowadays the issue is finding a monitor capable of displaying 50Hz vertical. Every display can handle 31KHz horizontal now, but 50Hz vertical - common in the CRT days - is unusual.

Many of us have had luck with a variety of Dell displays, mostly those that also have HDMI ports. There are a few threads around the forum about this. I'm using a Dell ST2320L, a U2410, and a U2412M successfully at 50Hz vertical.

The Indivision ECS is a more modern internal scandoubler that plugs into a chip socket (instead of the video slot) and has some extra logic to optionally bump 50Hz vertical output up to something that just about any LCD can display.

[raoulduke]

So I got a Viewsonic VA1912wb.  It's not a great monitor but it also detects no signal; and purportedly supports 50hz - someone (please) feel free to contradict me there.  It's starting to look like the problem is with the card itself.