mikeg@pro-charlotte.cts.com (Mike Gladden) (03/16/88)
Has anyone out there in netdom had any success using a digital RGB monitor with the A500? I have tried it with two different monitors to no avail. The cable was properly assembled, I'm sure, but for the record here's what I carried through: Red, Blue, Green, Intensity, Ground, Horizontal Sync, and Vertical Sync. I used the pin marked DGnd (I assume that meant digital ground) for the ground connection. Oh yes, I did use the DIGITAL RGB lines. The two monitors were an IBM Enhanced Color Display (which will sync on both CGA and EGA outputs) and a monochrome Princeton MAX-12 (which is also a dual sync monitor supporting both CGA and monochrome TTL). The problem is that no matter how much tweaking of the horizontal hold adjustments (both outside and the internal pots) we did, we couldn't seem to get the monitors to sync horizontally. What we got on the screen (very faintly) was something like: 1> 1> 1> 1> 1> 1> Is this a horizontal syncing problem? If so, why does it exist since the A500 and the A2000 (I assume) supposedly support digital RGB. If that's not what it is, what is it? Does anyone have any suggestions or solutions? I have an analog RGB myself and the friend who is trying to get the digital monitor to work is fully aware of the 16 color limit with the digital monitor, but he can't afford a new analog monitor right now, so we want to use the digital monitor temporarily till he can raise some funds. Thanks in advance, MIKE GLADDEN pro-charlotte
keithd@cadovax.UUCP (Keith Doyle) (03/17/88)
In article <2684@crash.cts.com> mikeg@pro-charlotte.cts.com (Mike Gladden) writes: >Has anyone out there in netdom had any success using a digital RGB monitor >with the A500? I have tried it with two different monitors to no avail. The >cable was properly assembled, I'm sure, but for the record here's what I >carried through: Red, Blue, Green, Intensity, Ground, Horizontal Sync, and >Vertical Sync. I used the pin marked DGnd (I assume that meant digital >ground) for the ground connection. Oh yes, I did use the DIGITAL RGB lines. I've done it, and I've got news for you, once you do, you'll realize it was a waste of time. At any rate, I don't remember the exact specifics, but I believe the Hsync and Vsync polarities are reversed. I have a cable here I made, which has a 74LS04 hot-glued to the 13 pin connector and runs Hsync and Vsync through it. Once you do this, you find that you have to adjust the heck out of preferences to be able to see what is going on on the screen, and there are several programs I seem to remember that override preferences settings resulting in completely unreadable displays. Anything darker than some % of full white ends up BLACK. I found most colors end up BLACK with many screens on an digital monitor. Keith Doyle # {ucbvax,decvax}!trwrb!cadovax!keithd Contel Business Systems 213-323-8170