Date   : Sun, 04 Jul 2004 23:44:23 +0200
From   : D.G.van der Pol <danielg@...>
Subject: Re: Acorn Winchester unit

Op 2-jul-04 om 15:03 heeft Richard Gellman het volgende geschreven:

> Jules Richardson wrote:
>
>> I found an Acorn Winchester unit yesterday. Still has the Acorn
>> Winchester board lurking below the Adaptec ST506-SCSI bridge board, 
>> and
>> a Rodime drive present. However, there's no case lid! If anyone ever
>> finds a shell of one of these in a skip, let me know :)
>>
>> I almost missed picking it up (I was sifting through a lot of junk at
>> the time) as I could see the Adaptec bridge board and figured I didn't
>> need another one of those - I have a few already. Without the case 
>> lid I
>> couldn't tell it was an Acorn unit, but luckily someone else pulled it
>> off the shelf and I saw Acorn written on the back...
>>
>> Q: what ROM(s) do I need present in the host system to drive this? 
>> Does
>> ADFS already contain code to talk to the Winchester board if present 
>> on
>> the 1MHZ bus, or do I need ADFS + some software, or is there a 
>> different
>> ROM altogether that I need?
>>
>> ta
>>
>> Jules
>>
> Yes, the ADFS ROM contains the code to access the drive over the 1Mhz 
> Bus. I'm led to believe there are some bizarre DFSes out there that 
> can handle hard drives too, but I wouldn't know which. ADFS works 
> better anyways.
>
> Note that you can't just nick the ADFS ROM code from a Master 128 if 
> you intend to use a BBC B. Firstly the ADFS ROM in the M128 uses 
> 65C12-specific opcodes, and the B's 6502 will just vomit at those, 
> secondly, if you try to use the ADFS with floppy disks it will b0rk, 
> even if you have a 177x controller fitted, as the B puts the FDC at a 
> different location to the Master.
>
> By the way, if anyone has an Acorn Winchester Host Adapter board (1Mhz 
> Bus -> SCSI board) they'd like to flog me, let me know. I'd like to 
> play with getting my 500Mb SCSI drive hooked up.
>
> -- Richard
>
>
Recently, I build a Winchester Host Adapter board because I would like 
to use some old scsi harddrive to store all my Master stuff on. As far 
as I could find, a standard 8-bit scsi drive should work just fine. I 
have a whole stack of them, ranging from 40Mb till 4 Gb.
Using the small programs in the Service Manual, I was able to debug my 
board as I build it on Vero-board with wires for every connection. Yes, 
it was two days work just to solder everything on. And another day to 
get the small glitches out.
But now I ran into a very stupid problem: All harddrives I have seem to 
be formated with 512bytes/sector or more. Most of the bit newer drives 
can be formatted with 1024 bytes/sector or more, but as the Master uses 
256 bytes/sector, I am not able to format them correctly.
Does this sound familiar, or did I overlook something. I used HDForm 
first to format, them I found Superform somewhere on the net. These 
programs don't seem to care that my drive is using 512bytes/sector but 
as soon as I start to save data on the drives, I run into problemes 
that invalid data is read from the disk.
Does anybody know a way arround this? Or is anybody able to sell me a 
harddisk with 256bytes/sector for very little money? Any help would be 
appreciated.

-Daniel G.