[net.micro.cbm] EPYX Fast Load and "Edit Disk" function

sauder@nbs-amrf.UUCP (Jeff Sauder) (04/28/86)

Recently I downloaded a sequential file from a bulletin board, only
to find that the file came across as a program file.  I realize
there are utilities to change the type of a file, but being a true
hacker, I decided that I must attempt to rectify the situation
myself.  According to my 1541 reference manual, the location of the
directory information resides on track 18.  However, when I
attempted to use the "Edit Disk" function of my EPYX Fast Load
cartridge to alter track 18, I found no information on track 18.
(According to the "Edit Disk" function, anyway)  I eventualy
located the correct information on track 12, altered the hex code
so that the program file was now a sequential file, and then
proceeded to use the sequential file for its desired purpose.  My
question, however, is this --  What is wrong with this particular
function on Fast Load?  I know that the information was really on
track 18.  Are all track numbers actually referenced by a number
six less than the true number (i.e. 12 instead of 18)?

Also, I attempted to write directly to track 18 of the disk with
limited success.  I tried to place the information '255' and '129'
into track 18, sector 1, bytes 3 & 4 respectively.  (129 is the
code for sequential files while 130 is the code for program files.
I was trying to replace 130 with 129 and I assumed that I also had
to write the previous 255 to the disk also, because I could find no
way of skipping over a byte within a sector.)  Anyway, I
accomplished the desired feat with undesirable side effects.  My
short little program continued writing '255' and '129' throughout
the entire sector.  All the odd numbered bytes had '255' in them
and all the even numbered bytes had '129' in them.  Is it possible
to write to only part of a sector, or must I write to the entire
sector when attempting a Block-Write?  

You can send me E-mail if you wish, but I'm willing to bet that
some others may be interested in this, too.  Thanks in advance.

-- 

Jeff Sauder     {seismo,umcp-cs}!nbs-amrf!sauder

hsgj@batcomputer.TN.CORNELL.EDU (Dan Green) (05/01/86)

In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP (Jeff Sauder) writes:
>Recently I downloaded a sequential file from a bulletin board, only
>to find that the file came across as a program file.  I realize
>there are utilities to change the type of a file, but being a true
>hacker, I decided that I must attempt to rectify the situation
>myself.  According to my 1541 reference manual, the location of the
>directory information resides on track 18.  However, when I
>attempted to use the "Edit Disk" function of my EPYX Fast Load
>cartridge to alter track 18, I found no information on track 18.
>(According to the "Edit Disk" function, anyway)  I eventualy
>located the correct information on track 12, altered the hex code
>so that the program file was now a sequential file, and then
>proceeded to use the sequential file for its desired purpose.  My
>question, however, is this --  What is wrong with this particular
>function on Fast Load?  I know that the information was really on
>track 18.  Are all track numbers actually referenced by a number
>six less than the true number (i.e. 12 instead of 18)?
>
>Jeff Sauder     {seismo,umcp-cs}!nbs-amrf!sauder

Well, I would bet a shiny new dime that Fast Load references ALL
numbers in base 16 (Hexadecimal).  Therefore, the directory is
on track 18 decimal, which is TRACK 12 in hexadecimal.  Though
I do not own Fast Load, I would guess that you should do all your
figuring in base 16.
-- 
Dan Green    Bitnet:  hsgj@cornella
---------    UUCP:    {decvax,ihnp4,allegra,vax135}!cornell!batcomputer!hsgj
             Arpa:    hsgj@batcomputer.tn.cornell.edu

brown@nicmad.UUCP (05/01/86)

In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP (Jeff Sauder) writes:
>Recently I downloaded a sequential file from a bulletin board, only
>to find that the file came across as a program file.  I realize
>there are utilities to change the type of a file, but being a true
>hacker, I decided that I must attempt to rectify the situation
>myself.  According to my 1541 reference manual, the location of the
>directory information resides on track 18.  However, when I
>attempted to use the "Edit Disk" function of my EPYX Fast Load
>cartridge to alter track 18, I found no information on track 18.
>(According to the "Edit Disk" function, anyway)  I eventualy
>located the correct information on track 12, altered the hex code
>so that the program file was now a sequential file, and then
>proceeded to use the sequential file for its desired purpose.  My
>question, however, is this --  What is wrong with this particular
>function on Fast Load?  I know that the information was really on
>track 18.  Are all track numbers actually referenced by a number
>six less than the true number (i.e. 12 instead of 18)?
>
>Also, I attempted to write directly to track 18 of the disk with
>limited success.  I tried to place the information '255' and '129'
>into track 18, sector 1, bytes 3 & 4 respectively.  (129 is the
>code for sequential files while 130 is the code for program files.
>I was trying to replace 130 with 129 and I assumed that I also had
>to write the previous 255 to the disk also, because I could find no
>way of skipping over a byte within a sector.)  Anyway, I
>accomplished the desired feat with undesirable side effects.  My
>short little program continued writing '255' and '129' throughout
>the entire sector.  All the odd numbered bytes had '255' in them
>and all the even numbered bytes had '129' in them.  Is it possible
>to write to only part of a sector, or must I write to the entire
>sector when attempting a Block-Write?  
>
>You can send me E-mail if you wish, but I'm willing to bet that
>some others may be interested in this, too.  Thanks in advance.

I too have said Fastload cartridge.  Your simple mistake is that you
are taking the decimal track number and applying it to Fastload.
It wants HEX track and sector numbers.  So, you should have entered:
	track  12	sector 01
Then it would have worked (and does work).
-- 

              ihnp4------\
            harvard-\     \
Mr. Video      seismo!uwvax!nicmad!brown
              topaz-/     /
             decvax------/

grwalter@watmath.UUCP (Fred Walter) (05/02/86)

Hello line eater, meet the world !

In answer to your question re:track number 18 being seen as track 12 - your
edit disk function either has a hex (base 16) mode, and you were in it
('12' is the hex value for 18) or it always displays track numbers in hex.

When doing things with sectors on the disk I prefer to read the entire
sector, then use the 'b-p' buffer pointer command to point to the starting
byte that I wish to read or change the value of, then write out the entire
sector again. The correct syntax for the commands is in your disk manual,
but use 'u1' and 'u2' to do your reading and writing, and not the 'b-r' or
the 'b-w', and you'll probably have less problems.

															Fred

UUCP  : {allegra|clyde|linus|decvax|utzoo|ihnp4}!watmath!grwalter
CSNET : grwalter%watmath@waterloo.csnet
ARPA  : grwalter%watmath%waterloo.csnet@csnet-relay.arpa

mjw@aluxp.UUCP (Michael Weber) (05/02/86)

In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP writes:

>...      According to my 1541 reference manual, the location of the
>directory information resides on track 18.  However, when I
>attempted to use the "Edit Disk" function of my EPYX Fast Load
>cartridge to alter track 18, I found no information on track 18.
>(According to the "Edit Disk" function, anyway)  I eventualy
>located the correct information on track 12, altered the hex code
>so that the program file was now a sequential file, and then
>proceeded to use the sequential file for its desired purpose.  My
>question, however, is this --  What is wrong with this particular
>function on Fast Load?  I know that the information was really on
>track 18.  Are all track numbers actually referenced by a number
>six less than the true number (i.e. 12 instead of 18)?
>
>Jeff Sauder     {seismo,umcp-cs}!nbs-amrf!sauder

	Jeff the sector and track information on the EPYX Fast Load
cartdridge must entered in HEX.  18(DEC) = 12(HEX).  I believe you
may also enter decimal numbers if you precede them with a dollar 
sign. $18 = 12.

-- 

Regards,				AT&T Bell Laboratories
Michael Weber				1255 South Cedar Crest Boulevard
ihnp4!aluxp!mjw				Allentown, Pennsylvania  18103

gibson@unc.UUCP (Bill Gibson) (05/02/86)

In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP writes:
>Are all track numbers actually referenced by a number
>six less than the true number (i.e. 12 instead of 18)?

I haven't used Fast Load, but my bet is that the track numbers
are interpreted as hexadecimal, since 12(base 16) = 18(base 10).
Does the product have a manual detailed enough to answer this?

Bill Gibson
gibson@unc                   ...[akgua,decvax,philabs]!mcnc!unc!gibson

werme@alliant.UUCP (Eric Werme) (05/03/86)

The 12/18 problem:  the directory is on track 12(hex), track 18(decimal)

I'm not sure about the B-W problem, I wrote Computers & ME Ltd.'s Note-Us
and do a lot of my own disk I/O.  Unfortunately, I can't remember just how
I did it!  Certainly I sent a full block at a time.  Abacus Software's
"Anatomy of the 1541" is absloute necessity if you intend to get close to
your disk drive....

ali@Navajo.UUCP (05/03/86)

By default the EPYX Fast Load Cartridge uses hex numbers for track and
sector numbers, and that is why "12" worked in place of "18". You can use
decimal numbers by prefixing them with a "#".

Ali Ozer, Ali@SU-SCORE, Ali@Navajo

jrg@hpda.UUCP (05/05/86)

There is no problem with the disk edit function.
It expects HEX track numbers. (0x12 == 18 decimal).

Jeff Glasson
Hewlett-Packard ISO
ucbvax!hpda!jrg

andy@cbmvax.cbm.UUCP (Andy Finkel) (05/06/86)

In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP writes:

>attempted to use the "Edit Disk" function of my EPYX Fast Load
>cartridge to alter track 18, I found no information on track 18.
>(According to the "Edit Disk" function, anyway)  I eventualy
>located the correct information on track 12, altered the hex code
> [...]
>track 18.  Are all track numbers actually referenced by a number
>six less than the true number (i.e. 12 instead of 18)?
>
>Jeff Sauder     {seismo,umcp-cs}!nbs-amrf!sauder

Well, Jeff, I think you've been bitten by a HEX bug...
I don't have EPYX Fast Load, but I do know that 12(hex) IS 18.

Perhaps someone with the EPYX documentation would like to comment
(on whether it takes track numbers in HEX ) ?

				andy finkel
-- 

			andy finkel
			Commodore(Amiga)
			{ihnp4|seismo|allegra}!cbmvax!andy
		or	 pyramid!amiga!andy


"I disclaim all responsibilities, all shapes, all sizes, all colors."

"Remember, no matter where you grow, there you are." - Buckaroo Bonsai.

kdf@ihlpa.UUCP (Ken Frantzen) (05/07/86)

> In article <273@nbs-amrf.UUCP> sauder@nbs-amrf.UUCP writes:
> 
> >attempted to use the "Edit Disk" function of my EPYX Fast Load
> >cartridge to alter track 18, I found no information on track 18.
> >(According to the "Edit Disk" function, anyway)  I eventualy
> >located the correct information on track 12, altered the hex code
> 
> Well, Jeff, I think you've been bitten by a HEX bug...
> I don't have EPYX Fast Load, but I do know that 12(hex) IS 18.

I have the EPYX Fast Load and it does use hex for the sector and
track input as do some other disk utilities. I actually find the
hex format more convenient since I'm usually following the link
pointers displayed in hex to find my problem.