Date : Mon, 23 Oct 2006 15:18:40
From : "Richard Gellman" <splodge@...>
Subject: Re: poorly master
> Charlie.Robson@... wrote:
>> Hi everyone.
>>
>> I have a master that is in need of some TLC. At the very least, a new
>> keyboard. The one I have has a couple of switches missing and some ugly
>> solderwork on the k/b pcb. Many keys do not register. The main PCB looks
>> to
>> be in good shape from a quick visual inspection.
>>
>> When I replaced its corroded battery backup and reset the cmos, the poor
>> blighter hangs at bootup. With a disk drive attached the drive spins and
>> the access led lights up, but I can't break into whatever's happening.
>> Inserting a floppy doesn't result in any seekage. I wonder might it be a
>> stuck key? Shift perhaps? I didn't check but perhaps the default break
>> operation is causing this?
>
> IIRC the disc has to be ADFS. The machine is trying to load the disc
> catalogue.
This is correct. When the Master series has its CMOS cleared, it causes
the default filing system to be 0. The ADFS is written such that if nobody
else claims the current FS ROM #, ADFS will, so ADFS becomes the default
FS. At the same time, it sets the "Directory" and "Boot" options, so the
Master will try to boot an ADFS disk.
Fortunately, the Shift key will actually _invert_ the Boot option, thus
causing it to become "don't boot the disk". The easiest way out of the
situation, is to select DFS and work from there, by holding down CTRL + D,
and pressing break.
A rough guide to the default config. is in the Master Welcome Guide, if
not the following will give you a reasonable configuration:
*CONFIGURE FILE 9
*CONFIGURE LANG 12
*CONFIGURE MODE 135
*CONFIGURE DELAY 30
*CONFIGURE REPEAT 5
*CONFIGURE NOBOOT
*CONFIGURE NODIR
*CONFIGURE NOTUBE
*CONFIGURE TV 0,1
*CONFIGURE FLOPPY
*CONFIGURE FDRIVE 0
This reads: Filesystem: DFS, Language: BASIC, Mode: Shadow Teletext,
Keyboard: delay 30ms, then repeat 5ms when key held down, Do not boot
disc, do not retrieve directory if ADFS is selected on break, do not
enable second processor, position the screen in a reasonably sane
position, use the floppy drive as drive :0 (as opposed to a potential hard
drive) and use floppy drive stepping option 0.
>> If I hold other keys at bootup time I can get to (from memory something
>> approximately like)
>>
>> Acorn MOS 3.10
>>
>> This is not a language
>> *
Now this is interesting. The average Master 128 has MOS 3.20, and doesn't
display its version number on startup. Is this some early prototype you
have? Can you confirm the display output?
The error "This is not a language" means that the ROM selected as the
default language ROM does not have its type bits set to indicate it can be
run in this way. When this happens the error above is printed, and the MOS
drops to the "supervisor prompt", aka a facility for entering * commands
to sort the problem out.
-- Richard