hull@hao.ucar.edu (Howard Hull) (11/21/90)
Since I got a bridgeboard for my A2000 at work, I have been trying to upgrade it to a reasonable level of functionality. The bridge comes with a CGA window attached via Amiga Intuition, and that doesn't hack it for what I need to do. I picked up a RenaissanceGRX card and have the following to report concerning the agonies of VGA with a bridge board in general and the RenaissanceGRX in particular. I have a Flicker Fixer and a Mitusbishi Diamond Scan AUM-1381A monitor. The Diamond Scan has a 9-pin TTL input and a 25-pin analog input. I have successfully used the GRX in TTL mode by connecting it to the Mitsu via a 9-pin straight through male to male cable. The TTL/VGA jumper on the GRX must be set to TTL, and the best performance level that can be had that way is IBM EGA (supposedly 16/64 colors - but there doesn't seem to be any MODETEST item to exercise the 64 color mode). However, it is nice to the bridgeboard text transfer memory area in EGA, so the Intuition text window works, and it is possible to access the GRX image output by merely flipping the TTL/ANALOG switch to TTL to see the GRX output, or to ANALOG to see the Amiga side. That is quite nice, really. The GRX VGA mode is another matter entirely. When I move the GRX jumper over to VGA, I have to turn off both the Monochrome and the Color Intuition Memory in order to get it to even try to boot, let alone boot successfully. I also have to use a 25-pin A/B switch box to flip between the Amiga Intuition image and the GRX VGA image. The boot is terribly inconsistent. With no floppy in the drive, it tries to find the C: autoboot file; under EGA this worked ok, but under VGA it fails to find the autoboot disk file on the Amiga HD. If I put the floppy in, it will boot to the floppy ok, and roughly half the time it will read enough of the C: autoboot file to mount it. The other 50% of the time it will just hang. Sometimes there is a message "Janus structure not found." Then there is yet another problem, and that is that the MODETEST EXE brings up the VGA modes in monochrome; this is the case for either of the two settings of the bridgeboard monochrome/color jumper. If I open the PC window, I can of course send commands to the A2286, and they do show up in the VGA side text window. I can issue a CTRL-ALT-DEL and the 286 will do a reboot - and after the reboot, the VGA goes to color and is the real thing it is supposed to be; BUT after this reboot, it is not anymore able to find the C: partition, even though it did access the Amiga HD (but for a seemingly shorter interval). The bootup declares the handler is Janus version 2.63 and the library is Janus version 1.33 (so if this isn't the latest version, and a newer version works ok, what do I have to do to get the latest rev, I wonder). So, questions: Does anyone else have a RenaissanceGRX VGA card working in an Amiga with a bridgeboard? If so, what did you have to do to get it to go? Also, what test do you run in order to check out the 64 color EGA mode? Last but not least, if you do use a VGA card with your A2286 bridgeboard and you find it satisfactory, who makes your card, and does it pass text to the Amiga side in a satisfactory way, i.e., can you leave the monochrome or the color Intuition transfer memory turned on, and is there relevant text there rather than gibberish? Email would be best for this, I think. Thanks in advance for any wisdom... Howard Hull hull@hao.ucar.edu