A statement to Commodore bridegboard users

[Xanxi]

Hello.

I have made a major discovery i want to share with you.

Until now, a Commodre bridgeboard with the Janus software could be used with a real hard drive connected to an ISA controller (not easy to set up), an amiga partition with some third party software from amibay (very difficult to set up), or use a hardfile created with MakeAB from the Janus software.

MakeAB can only create a 32 MB bootable hardfile and it is possible to add up to 4 virtual non bootable 32 MB hardfiles with the JDisk.device.
This is quite a limited disk space.

Now i have discovered that the Janus software can boot from much larger hardfiles.
MakeAB can't create them so another software is needed. I used PCTask to create a 250 MB hardfile and, after modification of PC.config, i have been able to use it with my bridgeboard.

I have been limited to 250 MB because PCtask can only create a hardfile into RAM: or DH0: and my boot partition is usually no more than 400 MB. Besides, the bridgeboard seems to only be able to boot from a hardfile located in DH0:
With a larger DH0:, i think the hardfiles could be up to 2 GB, depending of the BB bios. Larger ones could possibly be partitionned and formatted by third party MSDOS softwares (but not by MSDOS).

I have always been stuck by a small disk space with my A2386 BB. Now, this problem is solved without the hassle to have an ISA controller or risk trashing the whole hard drive by messing with partitions modification.

Large hardfiles are fast enough, providing you set enough buffers with addbuffers.

[spirantho]

Thanks for the information! I still like messing around with bridgeboards, though in fact all of my 386/486SLC ones are broken at the moment :/

When they do run, though, I use a real IDE HDD. Best thing is you can get those little Disk-on-Module things that are about 2 or 4GB or so, really cheap, really fast, really small and silent. I actually run my Goldengate (when it's working) off my A1500's DOM 4GB module which has a PC partition.

[freqmax]

Beware of any pointers that can wrap-around..!

[Zac67]

Beware of any pointers that can wrap-around..!

Yes! Do make sure the drive not only appears to work in that size but that it actually does work. It is quite possible that there's a pointer wraparound that e.g. causes block 65536 to be written to block 0. Fill the entire partition with data and verify that it's the very same data when read back.

[Motormouth]

Thanks Xanxi
I will try making one

[Xanxi]

It appears to be all good. I have already filled the 250 MB hardfile with more than 32 MB of datas and it is working fine so far.

@spirantho:
Obviously, if you have a Golden Gate BB, this does not apply to you. This tip is for Commodore A2088/A2286/A2386 which use the Janus package.

[freqmax]

Test: Write a program that generate a pseudo random sequence and write it to disk in 8 MByte chunks. Then resety the generator, and compare the generated sequence with the one read from disk.

Just filling with files and test they can be listed etc.. won't catch these nasty errors necessarly.

[orcish75]

Thanks for the info Xanxi,

When I set up my A2286 bridgeboard a couple months ago I used MakeAB to set up a hardfile. It was painfully slow and as you say has a 32MB partition size limit. Your new found discovery would've been great back then!!

In the end, I couldn't get the CrossDOS partition working, no matter how hard I tried, stuffed around for two weeks trying. I eventually went with a normal IDE HDD mounted on the IDE port of a Soundblaster 16, using the XTIDE Universal Bios mounted in an ISA network card boot ROM socket. This way I could have much better performance and an HDD up to 8GB on my A2286.

[Xanxi]

In the end, I couldn't get the CrossDOS partition working, no matter how hard I tried, stuffed around for two weeks trying. I eventually went with a normal IDE HDD mounted on the IDE port of a Soundblaster 16, using the XTIDE Universal Bios mounted in an ISA network card boot ROM socket. This way I could have much better performance and an HDD up to 8GB on my A2286.

What a peculiar setup! I though the IDE port of the SB16 was not bootable and not meant for hard drives. What is this XTIDE bios? Does MSDOS 5 and 6 recognize the 8 GB (there should be a limit at 2 GB in FAT16)?

[freqmax]

Using FAT16 with 64 kB clusters you can have 4 GB volumes.

[orcish75]

What a peculiar setup!

He, he! Yup, it is quite a hack, but it solves a few problems for me. First of all, the BIOS on the A2286 bridgeboard doesn't have an autodetect/custom parameters (cylinders, heads, sectors) setting for hard drives (AFAIK the A2386 does have this). It has the 47 preset values which ranges from about 10MB to 120MB. If you put in a drive that doesn't match the preset values exactly, the BIOS won't recognise it and you can't use the drive. Needless to say, finding drives these days that match one of those preset values is not easy.

The XTIDE Universal BIOS is a BIOS written by some guys that developed an IDE controller for XT PCs. Here's the link:http://code.google.com/p/xtideuniversalbios/   It gives old PCs a modern IDE BIOS that can autodetect the HDD, boot off the Primary, Secondary or Tertiary IDE controller and has a boot menu if you have multiple IDE drives with different OS's on each. It does have an 8GB size limit on the drive though. You can still connect a bigger drive, but only 8GB will be accessible. 8GB is more than I'll ever use on my A2286, so this is perfect.

The problem is that you have to burn the XTIDE BIOS into an EPROM and then get the PC to read that EPROM. The main reason why I got the A2286 was to use a PC ISA network card and hook it up to the A2000 using Etherbridge. The ISA network card has a boot rom socket on it, so this where the XTIDE BIOS EPROM was inserted, in order for the PC to read it.

The IDE controller on the SB16 is a standard ISA IDE controller, setup as the Secondary controller. It can't be jumpered to be the Primary controller without doing some hardware hacks on the board itself. This is the reason why you couldn't boot a hard drive off the SB16 back in the day, as most PC BIOSes could only boot off the Primary controller. The XTIDE BIOS allows booting off a Secondary controller, so I could save an ISA slot on the A2000, using the SB16's IDE controller instead of a separate multi I/O card for the IDE controller. The third ISA slot has a VGA card in it, so they're all occupied.

FAT 16 does allow 4GB partitions as Freqmax pointed out, but I partitioned the HDD (an 8GB Compact Flash card) into 2 x 2GB partitions. I know 4GB is not being used, but I doubt I'll ever use that much space on the A2286. I've installed MS-DOS 6.22 and Etherbridge on the first partition and a bunch of 286 era games on the second partition. It's great being able to play Prince of Persia in VGA with sound on the A2286 with decent speed from the IDE controller.

I'll set up a new thread on how to do all of this if anyone's interested as I've already hijacked Xanxi's thread with this ramble.

[mechy]

Hello.

I have made a major discovery i want to share with you.

Until now, a Commodre bridgeboard with the Janus software could be used with a real hard drive connected to an ISA controller (not easy to set up), an amiga partition with some third party software from amibay (very difficult to set up), or use a hardfile created with MakeAB from the Janus software.

MakeAB can only create a 32 MB bootable hardfile and it is possible to add up to 4 virtual non bootable 32 MB hardfiles with the JDisk.device.
This is quite a limited disk space.

Now i have discovered that the Janus software can boot from much larger hardfiles.
MakeAB can't create them so another software is needed. I used PCTask to create a 250 MB hardfile and, after modification of PC.config, i have been able to use it with my bridgeboard.

I have been limited to 250 MB because PCtask can only create a hardfile into RAM: or DH0: and my boot partition is usually no more than 400 MB. Besides, the bridgeboard seems to only be able to boot from a hardfile located in DH0:
With a larger DH0:, i think the hardfiles could be up to 2 GB, depending of the BB bios. Larger ones could possibly be partitionned and formatted by third party MSDOS softwares (but not by MSDOS).

I have always been stuck by a small disk space with my A2386 BB. Now, this problem is solved without the hassle to have an ISA controller or risk trashing the whole hard drive by messing with partitions modification.

Large hardfiles are fast enough, providing you set enough buffers with addbuffers.

Ditch janus and use SXSERV with a real Gfx card etc, it rocks. The latest Janus still had a few bugs if i recall. I always found hardfiles to be really slow no matter what you do.

mech

[Xanxi]

Ditch janus and use SXSERV with a real Gfx card etc, it rocks. The latest Janus still had a few bugs if i recall. I always found hardfiles to be really slow no matter what you do.

mech

Sxserv is not a replacement package but a commodity to ease the use of the automatic switcher of the BB (must be custom build).

ATUtilities from aminet claims to be a replacement package but there is not a single readme to explain what to do with a bunch of files in german.

For speed use massive addbuffers and it is very good (my harddrive is SCSI and gives 10 MB/s out of my Blizzard 2060, that helps).

[Xanxi]

He, he! Yup, it is quite a hack, but it solves a few problems for me. First of all, the BIOS on the A2286 bridgeboard doesn't have an autodetect/custom parameters (cylinders, heads, sectors) setting for hard drives (AFAIK the A2386 does have this). It has the 47 preset values which ranges from about 10MB to 120MB. If you put in a drive that doesn't match the preset values exactly, the BIOS won't recognise it and you can't use the drive. Needless to say, finding drives these days that match one of those preset values is not easy.

The XTIDE Universal BIOS is a BIOS written by some guys that developed an IDE controller for XT PCs. Here's the link:http://code.google.com/p/xtideuniversalbios/   It gives old PCs a modern IDE BIOS that can autodetect the HDD, boot off the Primary, Secondary or Tertiary IDE controller and has a boot menu if you have multiple IDE drives with different OS's on each. It does have an 8GB size limit on the drive though. You can still connect a bigger drive, but only 8GB will be accessible. 8GB is more than I'll ever use on my A2286, so this is perfect.

The problem is that you have to burn the XTIDE BIOS into an EPROM and then get the PC to read that EPROM. The main reason why I got the A2286 was to use a PC ISA network card and hook it up to the A2000 using Etherbridge. The ISA network card has a boot rom socket on it, so this where the XTIDE BIOS EPROM was inserted, in order for the PC to read it.

The IDE controller on the SB16 is a standard ISA IDE controller, setup as the Secondary controller. It can't be jumpered to be the Primary controller without doing some hardware hacks on the board itself. This is the reason why you couldn't boot a hard drive off the SB16 back in the day, as most PC BIOSes could only boot off the Primary controller. The XTIDE BIOS allows booting off a Secondary controller, so I could save an ISA slot on the A2000, using the SB16's IDE controller instead of a separate multi I/O card for the IDE controller. The third ISA slot has a VGA card in it, so they're all occupied.

FAT 16 does allow 4GB partitions as Freqmax pointed out, but I partitioned the HDD (an 8GB Compact Flash card) into 2 x 2GB partitions. I know 4GB is not being used, but I doubt I'll ever use that much space on the A2286. I've installed MS-DOS 6.22 and Etherbridge on the first partition and a bunch of 286 era games on the second partition. It's great being able to play Prince of Persia in VGA with sound on the A2286 with decent speed from the IDE controller.

I'll set up a new thread on how to do all of this if anyone's interested as I've already hijacked Xanxi's thread with this ramble.

Very interesting.
You are welcome to hijack anytime with such informations :-)

[orcish75]

(my harddrive is SCSI and gives 10 MB/s out of my Blizzard 2060, that helps)

Ah! Now I see why you're not complaining about hardfile speeds!

Using a hardfile on my GVP HC+8 for the PC side was abysmally slow, hence I used a dedicated IDE controller for the HDD.