Bridgeboard HD Access
17 messages in this thread
I used MAKEAB to create a bootable hard disk for my XT bridgeboard. The
HD access on the MSDOS side is extremely slow. Is there any way to speed
it up?
I have an A2000, A2088, A2091, A2052. Thanx! —Mike
Mike …
Not really. That's the bad news about MAKEAB. It seems to be about half the
speed of the drive on the Amiga side.
Marion Deland
CROSSINGS (Bridgeboard newsletter)
Ah well. Thanx for the info. —Mike
The slowdown is the movement of data thru the dual ported RAM on
the BB, and thus…I'm afraid you'll have to live with it. The best you
can expect is about 70Kbytes/sec.
Don
Don:
I've been thinking about something for a while, and so let me see what you
think of it.
What would happen if I take my GVP SCSI host adapter, reset it's ID from 7
to 6, then hookup an XT SCSI adapter as ID 7 and then format a partition on
one of my drives using the XT adapter's ROM routines, fdisk, etc, and then
mount that partition on the Amiga side using CrossDOS? Is it possible for 2
SCSI host adapters to co-exist on the same bus? What are the possible
problems I would have with this setup? Can pluging in the second host
adapter onto the SCSI buss blowup (fry) any of the stuff on the buss?
(HD's, or GVP card)?
-Mike Schiller
In sunny Fort Lauderdale
Mike,
Under the current SCSI design used by all (that I know of) Amiga
host adapters, there can only be 1 host. Under differential SCSI, there
can be more than one host, but I know of no one making a differential host
adapter for the Amiga.
But, what you can do, is set up an XT host adapter on the Bridge
side and attach and partition one of your drives for MS-DOS on that drive,
and partition the rest of the drive using ADISK as an Amiga drive (via
DJMount).
Yes, that partition will be slow, but if you plan carefully, I
think you'll find that you can do 99% of your work on the native Amiga
drive and hardly use that DJMounted drive much at all.
The MS-DOS partition on that drive however, will be 'full speed'
since it's directly connected to the XT bus.
I've got 100 Meg on the Amiga side of my setup, (over 3 HD's) and I
hardly ever use 20 of that. I've also got a 4th HD on the MS-DOS side (20
Meg) so I don't need to make a separate parition for either side to
share…but if I had to…I could easily have moved that 20 Meg from the
Amiga side to the MS-DOS side and hardly miss it at all.
Don
Don:
I've gone that route before (having a separate drive for the BB) and my
reasons for the dual host question were more to have the ability to use
CrossDOS to access the partition as well as the BB.
-Mike Schiller
In sunny Fort Lauderdale
Mike,
Ok…then I guess the answer to your question is no, as far as I
know.
Don
Mike;
I don't know about the GVP (probably should talk to them) but the (now
defunct) C-Ltd Kronos SCSI controller would do just exactly what you
wanted. I suspect that if you can reset the GVP's controller address to
something other than 7, it will probably work too. Of course that is only
half of the problem as the BB SCSI controller has to be willing to give up
the bus too. I would imagine that it makes more sense to leave the GVP as
the master and have the BB controller ask for the bus when it wants it.
73, bill
Oh well. Thanx for the info. —Mike
The dual ported RAM really slows things down both ways. I have a PC/XT
controller with my Bridgeboard, and the fastest access I can get on the
Amiga side (using Diskspeed 3.1) is 22K/s. While my new GVP/Quantum pair
can get up to over 600K.
Kevin Ushko
Edmonton, Alberta
Thanx for the info. —Mike
Mike;
As already mentioned, there is no much that you can do. Using some form of
diskcaching on the PC side could improve repeated access but that is about
it.
73, bill
The Plus Development Hardcard XL 50 makes a nice addition to the AT BB. It
appears to be a well designed card (best looking hardcard that I have seen
to date). It is quite fast (bridge board is almost a pleasure to use. It
would be if it wasn't for the OS 🙂 ). The card clears the Zorro II
connector quite nicely (most do not). Installation is a snap except that
you MUST rename "format!com" to "format.com" for the installation to work
(that one is not their fault).
The one sour apple is that the card won't boot with revs 3.5/3.6 of the
bios. The Plus Development folks told me that BEFORE I bought the card. In
fact the guy was really concerned that I clearly understood him. He did
say that they are trying to fix the problem by working with the bios
writer.
On the positive side, the boot from floppy and switch to hd is almost
complete by the time that the amy SS is complete anyway. The boot from
floppy to hd is complete considerably quicker than a boot through janus! As
far as I am concerned, having to have a bootable disk in the A: drive is a
minor inconvenience for such a high performance drive. BTW, directories
list much nicer too…… I had not thought about the fact that much of the
screen disturbance is due to the disk related data that must be transfered
rather than the display data.
I mark this one a highly recommended.
Usual disclaimers apply: your mileage may vary; I don't work for the folks;
if your machine blows up, I am probably legally certifiable anyway……
73, bill
What is the price of the XL 50? I don't want to waste, err spend much
money for the MSDOS side; I use it only for PrintShop and Word (my wife
uses Word at work). —Mike
Mike;
Ahhh, let me go look……. $459.00 is what I paid at a retail computer
store so you probably can beat that some.
73, bill *********** MERRY CHRISTMAS *************
Bill,
Thanx for the info, but that's more than I paid for the BB. —Mike