Re: Auto Boot - and the & command.

Hello Spiro,

Sunday, April 7, 2013, 4:24:05 AM, you wrote:

> Hello,

> * On Sat, Apr 06, 2013 at 10:09:16AM +1100 Julian Perry wrote:
>  
>> That's still in the 1541 ROMS, as late as 901229-03 which executed this code if ATN (I
>> think) was low when the drive booted - my first 1541 (long gone)(short
>> board) actually had it.
>> 
>> Somewhere between -03 and -05 this autoexec code was removed, but the

> Does anyone know if there actually exists a -04 ROM? I newer saw one
> mentioned (other than me asking this question over and over again on
> different forums...)
No - I have never seen a 901229-04 ROM . I came to the conclusion that
it must have been an internal revision, never released.

>> "&" DOS command remains. I suspect the autoexec code was used as a
>> development tool, facilitating a direct bootstrap from disk.

> I am not sure if this was a development tool, or if CBM had something
> actually planned with this. If it would not been present in the 2031 and
> 1540, I would have expected it to be related to CP/M. But as the facts
> are currently, this is not very likely.

>> Presumably it was removed because it often caused the drive to load
>> the error channel with error 50 (Record not found) on power up - and the drive
>> error LED would flash.

> Did you actually notice this behaviour ever? My drive has a -05 ROM, but
> I tested with a -03 ROM in order to find out why it might have been
> removed, and I never encountered any problems whatsoever.
Yes. I do recall seeing it frequently. If you asked me for the
sequence to reproduce it, I honestly couldn't tell you. (it WAS 28
years ago!)

The only thing I DO remember was that it started happening when I bought
a printer (Star Micronics Gemini 10X) and serial adapter. Presumably
the loading of the IEC buss by that device fooled the drive into
running the code.

I don't have that drive anymore - I literally wore it out, and it
couldn't hold an alignment anymore. Stripped it for parts. (the
transformer ended up as a modem power supply for our BBS!!!!)`

Julian



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