Hi.  The Bvision (Like the A4000 CVision) is a RTG only card. I take it you are using either Cybergraphx or a newer Icomp P96 (Picasso96) to display your Workbench?
I’m guessing you have a RGB to VGA for native modes?

The way I do this these days is with a Scandoubler/Flickerfixer like a Icomp AGA which clips onto the Alice chip. Then I use something called a RATTE auto monitor switcher which uses a small Piece of software in Startup-Sequence called “SwitchControl”.
The RATTE uses a clip on over a CIA to monitor Native to RTG switching.

The RATTE can be bought over on Amibay. Software from here https://www.ikod.se/ratte-auto-switch/

      To see photos and a video link of the event, go to

http://blog.retro-link.com/2026/03/commodore-amiga-at-fresno-state-science.html

          Truly,
          Robert Bernardo
          Fresno Commodore User Group - http://www.dickestel.com/fcug.htm
          Southern California Commodore & Amiga Network - http://www.portcommodore.com/sccan
          April 25-26 Commodore Los Angeles Super Show 2026 - http://www.portcommodore.com/class

Hi

To make a long story short, i used to spend lots of time on Amiga with my brother in the late 80's and the whole 90's.
After that the Amiga has just been sitting there, but finally got around to fire it up again.

I have an A1200 in a Towerhawk case, so using an ATX power supply and PC keyboard.
As my old HDD and floppy has retired, i have installed a GOTEK and an AmigaKit CF drive.

Installed 3.1 kickroms and now running AmigaOS 3.9.
I also have a Phase 5 68040 PPC card fitted with a Bvision, with a VGA output.

After much fiddling, as i have forgot much on the Amiga, much has come back to me but this still puzzles me.

I can output the workbench to my VGA monitor, but not most games and demos. This has to do with the old RTG on 15 khz, which is not compatible with the newer monitor and Bvision, i understand.
Im pretty sure we had everything outputted on the VGA monitor back in the day, but not sure how.

How can i get around this? Is a scandoubler the only way, or can i force the Amiga to output everything to the Bvision with software somehow?
Hope this makes sense.

Mosher

There are quite a few oldschool Amiga OCS/ECS demos that will run as intended, perfectly, smoothly only on base Amiga 1000, 500, 2000 systems with 68000 CPU -- unaccelerated. One example is TBL's Eon (2019) -- an incredible demo.

I've encountered a very few games that fall into this category also.

Will these run properly with 68000-emulator accelerators such as the PiStorm? It emulates the 68000, but can it do so with 100% never-failing, cycle-exact precision when operating as a base, unaccelerated 68000 at 7.16/7.09 MHz?

The demos I speak of fail to run or run visibly broken with most accelerators, including my A2620 (14.32MHz 68020).

...what I am actually looking for is an accelerator - of any sort - for my NTSC Amiga 2000 (6.4 NTSC motherboard) that has a physical switch to allow it to be disabled to easily enjoy these demos without having to do the mouse-button menu dance to enable/disable the accelerator. Given that I cannot apparently attach a switch to the pads on this board to switch between NTSC and PAL, I have to boot into Degrader and go to PAL for demos, and in combination with the mouse-button menu for 68000 mode and the retention behavior (or lack there of) after reboots makes this maddening. I want an accelerator with a HARDWARE SWITCH that lets me enable or disable acceleration. I just assumed that the emulated-68000 boards are not precise enough for such time-critical demos.

(Someone out there added a switch to their A2630 (nearly identical board to my A2620) - and so doing so to my board is theoretically possible, but looking at the schematics, it's beyond my abilities, quite sadly.)

Thanks.

You might have an intermittent connection problem on the main board.
Have you tried reseating the KS ROM chip?
Which ROM version are you using? Anything else connected on the main board? Floppy disk drive connected still?
Are you using a HDD drive on the IDE header?