[comp.sys.apple] EXEC-ing Sound Progs

abc@BRL.ARPA (Brint Cooper) (06/02/88)

	Recently, a series of six (6) files was posted to APPLE2-L.
When EXEC-ed, they produce binaries which will generate music when used
with an Apple sound program.

	I have downloaded the third of these six on two different
occasions, and, each time, received "ERROR" upon EXEC-ing them under
PRODOS 1.0.1 on an un-enhanced Apple IIe.

	Does anyone know why?

_Brint

SEWALL@UCONNVM.BITNET (Murph Sewall) (06/03/88)

>    I have downloaded the third of these six on two different
>occasions, and, each time, received "ERROR" upon EXEC-ing them under
>PRODOS 1.0.1 on an un-enhanced Apple IIe.

While I can't help you with the music program question (that error message
occurs when, for any reason the EXECUTIONER file is corrupted) because
I haven't tried to download that.  I can help with ProDOS (BOY is 1.0.1
out of date!).  I got a copy of 1.4 with my latest edition of Copy 2+,
I can upload an EXECUTIONER file of ProDOS 1.4 and mail it to you if you'd
like (many bug fixes since 1.0.1).

JDA@NIHCU.BITNET (Doug Ashbrook) (06/04/88)

>     Recently, a series of six (6) files was posted to APPLE2-L.
> When EXEC-ed, they produce binaries which will generate music when used
> with an Apple sound program.
>
>     I have downloaded the third of these six on two different
> occasions, and, each time, received "ERROR" upon EXEC-ing them under
> PRODOS 1.0.1 on an un-enhanced Apple IIe.

Just last night I had a similar problem downloading a file with
Kermit 3.83.  Normally I have a clean phone connection and no retries
are needed.  But last night I must of had a noisy phone connection
because many retries were occurring.  When the packet was
re-transmitted, Kermit did not throw away the bad packet.  Each time
I attempted to EXEC the file after any retries had occurred, I got
the "ERROR" message.  I was finally able to download the file without
any retries and it then EXECed cleanly.

Has anyone else had any problems with Kermit not discarding bad
packets?

-------------------------------------------------------------------
J. Douglas Ashbrook                                  (301) 496-5181
BITNET: JDA@NIHCU            ARPA: jda%nihcu.bitnet@cunyvm.cuny.edu
National Institutes of Health, Computer Center,  Bethesda, MD 20892

SEWALL@UCONNVM.BITNET (Murph Sewall) (06/04/88)

>Just last night I had a similar problem downloading a file with
>Kermit 3.83.  Normally I have a clean phone connection and no retries
>are needed.  But last night I must of had a noisy phone connection
>because many retries were occurring.  When the packet was
>re-transmitted, Kermit did not throw away the bad packet.  Each time

Did it not discard ANY of the bad packets or only some of them (one
would have been enough to FUBAR the EXECUTIONER)?

>I attempted to EXEC the file after any retries had occurred, I got
>the "ERROR" message.  I was finally able to download the file without
>any retries and it then EXECed cleanly.
>
>Has anyone else had any problems with Kermit not discarding bad
>packets?

I've never had that problem downloading text files.  I occasionally
get a retry and haven't gotten an extra packet (perhaps it depends on
exactly what error requiring a retry occurs).

Is it possible that the bad packets generating retries WERE replaced,
but that at least one packet was accepted (correct checksum character)
that should not have been?  There's a 1 in 256 chance of that happening
in XModem given a bad block, and if I understand Kermit's error checking,
the same odds apply.

I have had trouble downloading binary files (from IBM to IBM over
bitnet where no translations to ASCII intervene, binary transfer will
work).  Evidently the one character block-check (the only level Kermit-65
supports) is insufficient to insure against bad blocks in 8bit transfers.
I've received corrupted binary code even when there were NO errors
resulting in retries (confirmed by uploading the file and comparing
byte-for-byte against the original).

The Kermit protocol provides for up to 3 character CRC error checking.
The MS-DOS docs note that SET BLOCK 3 should be used when transerring
binary files.  However, I've been under the impression that SET BLOCK 1
is sufficient for 7-bit transfers.

I assume that providing for SET BLOCK-CHECK 2 (or 3) in Kermit-65
would involve a LOT of overhead that might create other problems or
expand the code beyond the capacity of 48K Apple 2's (?).

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ARPA:   sewall%uconnvm.bitnet@mitvma.mit.edu       Murphy A. Sewall
BITNET: SEWALL@UCONNVM                          School of Business Admin.
UUCP:   ...ihnp4!psuvax1!UCONNVM.BITNET!SEWALL  University of Connecticut