Re: ][ plus crashing problem

[Rubywand <rubywand@swbell.net>]

Stephen Shaw wrote:
> 
> On Tue, 15 Jan 2002 03:15:20 +0000 (UTC), Jonathan Adams wrote:
> 
> > My Apple ][ plus clone crashes while trying to start certain ProDOS
> > programs. It will get to the ProDOS boot screen, and then it will lock up.
> > These are programs that I know are supposed to work with the ][ plus.
> > Any ideas on what the problem might be?
> 
> ProDOS does certain ID bit checks, that is why it did not work with the
> Franklin clone.
> What version of ProDOS are you using?
> 
 ....

     Here is a snip from the Apple II FAQs which should help ...


ref: ftp://ground.ecn.uiowa.edu/apple2/Faqs/Csa2DOSMM.txt
     http://home.swbell.net/rubywand/Csa2DOSMM.html#039

__________


From: Supertimer, Rubywand, David Wilson, Steve Jensen 

039- How can I boot ProDOS on my Franklin computer? 

     In an old Apple Clinic note, Stephen Craft listed specific locations to 
change after your Franklin freezes. You could then restart via a 2000G from the 
monitor. Here is an updated listing showing the locations to change for 
several versions of ProDOS: 

v1.1.1    $269E: EA EA 
v1.4      $282B: EA EA 
V1.6      $282B: EA EA 
v1.7      $282B: EA EA 
v1.8      $2836: EA EA 
v1.9      $2865: EA EA 
v2.0.3    $2836: EA EA 
  

     It turns out that the bytes Stephen was diddling are D0 03 in the sequence 
69 0B D0 03 A5 0C 60.  The sequence is near the end of a routine that checks 
for the "APPLE ][" string found in all genuine Apple II ROMs but not in most 
Apple II clone ROMs. 

     To fix the booting problem, do this: 

 Start Copy II+ and select "Sector Editor" 

 Swap-in the ProDOS diskette 

 READ Track 0, Sector 0 

 Search for (Hex bytes): 69 0B D0 03 A5 0C 60 

 When you find the above, change the D0 03 to EA EA 
 and write the changed sector back to diskette. 

     The patch eliminates the checksum test/branch and allows ProDOS to boot 
on Apple II clones which would normally fail the check. This patch has no effect 
on ProDOS functioning on regular Apple II's. 
  

     The above patch is absolutely necessary to get a bootable ProDOS working 
for many Apple II clones. Jim Sather (inCider, March 1986) recommends a second 
patch which is optional. It prevents ProDOS from erroneously reporting that 
a //e-style 64K 80-column card is present when running on a Franklin. 

Note: This patch should not be applied except by Franklin 1000 series and, 
possibly, some other clone users. On a //e, //c or IIgs it causes ProDOS to not 
see an 80-column card or some extra memory. 
The patch is not needed for Franklin 2000 series machines (the ones that emulate 
a IIe and IIc) or any of the Laser 128 series. You would not want to apply the patch 
to these units because they have emulated 80 column cards and 128k (expandable 
to 1MB on Lasers). 

     To do the patch, procede as described for the main patch and also do this ... 

 READ Track 0, Sector 0 

 Search for (Hex bytes): AE B3 FB E0 38 

When you find the above, change it to A2 EA EA E0 38 and write the changed sector 
back to diskette. 

__________



Rubywand