Bridgeboard emulation (x86 CPU, for example A2286)

Hello, first of all: Great work! Since I watched MIG's Yesterchips episodes on Youtube I wanted to try the bridgeboard experience myself, and am glad that this is now possible without buying expensive old hardware that often needs to be refurbished (think old clock batteries...) and I am not that skilled at using the soldering iron to be able to do these repairs.
However, I could not find the BIOS files, they do not seem to be in the Zone any more. Could anyone re-upload them there? Thanks in advance.

[AMIGASYSTEM]

The archive is still present "In The Zone" name file:

accelerator_roms [10.1.2015: GVP A3001 IDE.].zip

[Arnie]

Or you can look for expansion_boot_roms.zip

Thanks for the quick reply, but I can't seem to find any bridgeboard ROMs in there. I found expansion_boot_roms, but there are no bridgeboard BIOSes inside, and the "accelerator_roms" does not seem to be there.

[AMIGASYSTEM]

Ciao Windfisch, the file is in The Zone, before writing I checked, probably you are looking in the wrong place, if you type in on Google "accelerator_roms [10.1.2015: GVP A3001 IDE.].zip" in quotes ("") find it anyway.

Thank you, googling for it provided me with a link where I could download it.

EDIT: Seems I frolicked too early, no bridgeboard BIOSes in these files either...

[AnnaWu]

I still have hope Toni can add a SB Expansion Board.

@Toni: Thanks for reuploading an expansion_boot_roms.zip which has Bridgeboard BIOS in. I tinkered with it a bit and tried to recreate the "original" configuration. I set up an A2000 with 1meg Chip and Kick 1.3. Here are my findings:

- A2088 with XT-IDE: Working, but trying to use djmount fails with a Divide error on the PC side
- A2286 with AT-IDE: Works, but only for the first boot. Harddisk is recognized correctly, DOS boots and djmount finds and adds JH0. However, when resetting, binddrivers gets stuck for several minutes, and trying to re-open PC Window or djmount fails because janus.library failed to load. It works again when I quit and re-start WinUAE.
- A2386sx: Not yet tested.

Did anyone notice a similar behavior with the A2286?

EDIT: Turned out that the lockup issue was due to the BIOS. When using the BIOS 4.2, it seems to work now

[Toni Wilen]

Originally Posted by Windfisch

@Toni: Thanks for reuploading an expansion_boot_roms.zip which has Bridgeboard BIOS in. I tinkered with it a bit and tried to recreate the "original" configuration. I set up an A2000 with 1meg Chip and Kick 1.3. Here are my findings:

I am not sure if I understood what are you trying to do. Original bridgeboard config does not include XT-IDE or AT-IDE controllers.

Yes, I know. I wanted to emulate an Amiga with a bridgeboard and a hardcard attached to it, with one partition shared to the Amiga side.

[Toni Wilen]

Originally Posted by Windfisch

Yes, I know. I wanted to emulate an Amiga with a bridgeboard and a hardcard attached to it, with one partition shared to the Amiga side.

Ok but then you need to include much more information. (I typed "djmount", it complained about no drives with XT IDE HD in use. I lost interest. The end )

Probably something is not correct reset if restart was needed. (Log probably shows something)

EDIT: Example (can be mostly empty) djmount compatible hardfile probably would help.

Here is what I did:

- Set up a configuration with 68000, 1MB Chip, KS 1.3 and A2088 BIOS 3.6.1
- Used XT-IDE 2.0.0 Beta 1 ide_xt.bin at address 0xEC000 (Betas 2 and 3 do not detect any drives) (Had to force WinUAE to use it - first set the ROM to "ROM disabled", then manually selected path)
- Used a 40MB hardfile, which I set to RDB mode and entered the manual geometry: 7 surfaces, 17 sectors, 688 cylinders
- Booted from the PC Install 33.4 (got it from amiga.resource.cx)
- Set address to E000 in PCPrefs (in Markt&Technik's book about the bridgeboards they say for 2088(T) you have to use E000 instead of D000)
- Booted the 2088 from Commodore_A1060-A2088_MSDOS_1987.img
- Used ADISK on the PC side to assign all space to the virtual harddisk
- Rebooted the emulated Amiga completely
- Typed djmount in the shell. This took some time, after some seconds there was an access to the floppy disk, djmount got stuck and in the PC Window I saw "Divide overflow"

EDIT: Here is a link to the file: https://www.dropbox.com/s/5oizfc81ut...-40meg.7z?dl=1

With the 2286 I got it working, but had some issues with BIOS saving. Here is what I did:
- First set the card's memory to only 1MB.
- Used the BIOS 4.2 first, booted again from the Janus Disk 33.4
- When it complained that the configuration is wrong, I went into the BIOS setup to set the floppy disk drive and picked an appropriate harddisk of a size I wanted to use, and noted CHS (I noticed that base and extended memory were both shown as 0, and not changeable)
- After rebooting the BIOS showed (as expected) a hard drive error (no hdf yet configured), but also a memory error
- I then created a HDF which was slightly larger than the one I set in the BIOS
- Attached it to AT-IDE, used RDB mode and manual geometry. I entered the number of heads into the "surfaces" box, the number of sectors in the "sectors" box and made sure the number of cylinders was greater than what I noted
- Set the Bridgeboard memory to 2 MB now
- Booted from PC Install again
- Used ADISK to create an Amiga partition
- Rebooted Bridgeboard
- Typed "djmount ffs", and it worked (showed "not a DOS disk in JH0", and "format drive jh0: name Harddisk quick ffs" also worked)

[Toni Wilen]

Thanks. I tried your A2088 config but djmount still refuses to see any Amiga partitions. PC side Adisk (and fdisk) show the Amiga partition. Probably some janus.handler/XTIDE bios compatibility problem.

I think it is an XTIDE BIOS incompatibility because in this old post here:
https://groups.google.com/forum/#!to...ch/QTriPqkf738
one experienced this problem on a real A2088 with a real hard disk controller.

Did you experience the other issue about memory recognition on the A2286 emulation and not being able to select the correct setting in the BIOS setup?

[Toni Wilen]

Originally Posted by Windfisch

Did you experience the other issue about memory recognition on the A2286 emulation and not being able to select the correct setting in the BIOS setup?

No. A2286 also seems to work fine with djmount.

But 3.6 BIOS seems to have problems with VGA board, it does odd IO accesses and then hangs.

EDIT: Initial totally empty CMOS RAM probably sets some odd defaults.

A2286 works fine with AT-IDE djmount for me, too. However, when using BIOS 3.6, it only works once, and rebooting causes binddrivers to hang for a few minutes, resulting in janus.library not being able to be loaded. The only thing that works then is quitting and restarting WinUAE.
With the 4.2 BIOS it works fine, although it has problems with the memory configuration. When starting with 1MB bridgeboard RAM and a totally empty CMOS file, I get a disk drive and a memory error. Setting the disk drive and the hard disk causes the memory error to persist. When setting the board to 2 MB RAM, it discovers 1,6MB in total and the error goes away. However, when setting the memory to any other value, the memory error reappears and I cannot change the settings in the BIOS. It simply does not let me, the memory size is fixed.

I also had a go with the A2386SX emulation. There, I can set the memory size. However, no matter what I set, the memory configuration error never goes away. What I also noticed, is, that even the A386SX does not have any memory between 640K and 1024K available, so I cannot use DEVICEHIGH and LH in autoexec.bat. But I think this has to do with the CPU emulation and originates from Dosbox.

But nevertheless this is a great and interesting project and I love to tinker with this. And I still find that the bridgeboard idea is not THAT bad even with today's powerful computers being able to emulate nearly everything. I'd totally buy a PCI(e) board, USB or Thunderbolt box with hardware similar to the MiST or the FPGA Arcade on it, working similarly to the old Janus software. When only using PAL resolutions it would be possible to transfer the picture without any noticeable latency even over USB2, using some lossless codec.

[Toni Wilen]

I'll probably improve it after 3.2 is out. A2386SX highmem/shadowmem/whateverstupidmem support does not exist yet.

[Toni Wilen]

Originally Posted by Windfisch

When starting with 1MB bridgeboard RAM and a totally empty CMOS file, I get a disk drive and a memory error. Setting the disk drive and the hard disk causes the memory error to persist. When setting the board to 2 MB RAM, it discovers 1,6MB in total and the error goes away. However, when setting the memory to any other value, the memory error reappears and I cannot change the settings in the BIOS. It simply does not let me, the memory size is fixed.

Typing correct memory value (640 and 1024) worked for me. I don't think this is wrong (unless someone with real A2286 using same bios and empty CMOS RAM says something else), ancient PC BIOSes can be quite strange.

[Toni Wilen]

Originally Posted by Windfisch

I also had a go with the A2386SX emulation. There, I can set the memory size. However, no matter what I set, the memory configuration error never goes away. What I also noticed, is, that even the A386SX does not have any memory between 640K and 1024K available, so I cannot use DEVICEHIGH and LH in autoexec.bat. But I think this has to do with the CPU emulation and originates from Dosbox.

Could you include some test disk image or hd image that includes all required commands to duplicate this quickly and easily?

[Viceroy]

Could someone please tell me if this is still in The Zone, I can't seem to find it?
accelerator_roms [10.1.2015: GVP A3001 IDE.].zip