CDs as a storage device -- my successes and failures thus far
9 messages · 2004-09-16 → 2004-10-24 · Yahoo Group era · View archive on archive.org
Participants: Bruno Florindo, hatulzabad, Philip Kendall, Johnny Red, Jeff, Fred, David Solly, joe schmoe
Preserved from the Timex/Sinclair 2068 Yahoo Group (2001–2019), which is no longer online. Text reproduced from the archive.org archive; email addresses masked.
Messages
1. CDs as a storage device -- my successes and failures thus far
hatulzabad · Thu, 16 Sep 2004 15:11
I have recently acquired a pc with the ability to burn CD-ROMs
and have been experimenting with the idea of saving my library of
Timex/Sinclair 2068 and ZX Spectrum 48 tapes as sound files that
will reload into the original computers as if loading from a
cassette tape. For my first experiment, I saved the contents of a
cassette tape to a WAV file using Roxio. Using the Roxio sound
editor, I was able to partition each program so they would save as
separate bands on the CD-ROM. (I was even able to eliminate the
"kathunk" between programs where the tape had been started and
stopped.) I then saved my work as a music CD. Using this CD, I
was able to load the programs I had saved with the aid of a small
pre-amp. I was also able to skip directly to the program I wanted
from the CD without having to play through the entire CD. This
looked to be very promising except when I tried to do the same with
another tape, it was a total failure. The problem was that the
second tape was very dirty and, as yet, I am not enough of a sound
engineer to know which frequencies to boost or suppress to obtain
a cleaner tape. So the bottom line with this method is that the
chances of being able to burn a CD that will reload into a real
Sinclair computer depends upon the state of the original tape and
the ability to do a clean transfer from tape to CD.
After stewing a bit over my failure with the second tape, I began
to wonder why I could not convert the TAP files I had created with
Lunter's Z80 Spectrum emulator directly into sound files. This
would surly eliminate the hiss and rumble found on most cassette
tapes and greatly increase the chances of a successful load. I
used Lunter's TAP2VOC conversion utility in conjunction with
another utility to convert several TAPs into WAV files which I then
burned as a music CD. The result was I had a CD of beautifully
clean sound files but the files were compressed to such a degree
that they would not load into a real Sinclair computer. They
sounded like the game programs that required Hyperloader. However,
the VOC files I created and burned as data files reloaded
beautifully into Lunter's emulator even though they originated from
a CD. Still, the VOC files were in a compressed state and could
not be played on a standard CD player or reloaded into a real
Sinclair computer. If I hope by this method to have a CD that will
load into a real Sinclair computer, I need to find a way to
decompress the VOC files to a point that they can be recognized by
the original computers.
Some of you may be wondering why I am going to all this trouble
to create sound files when I could just as easily save emulator
MDR, TAP, Z80 and suchlike files. The reason is that I would want
files that will reload into the original computers. The second
reason is because emulator file characteristics change from
emulator to emulator and pc platform to platform, I want something
that is common to all systems.
Thank you all for hearing me out. Any ideas and/or suggestions
would be welcome.
David Solly
2. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
Philip Kendall · Tue, 21 Sep 2004 22:55
On Thu, Sep 16, 2004 at 03:11:56PM -0000, hatulzabad wrote:
>
> Some of you may be wondering why I am going to all this trouble
> to create sound files when I could just as easily save emulator
> MDR, TAP, Z80 and suchlike files. [ ... ] The second reason is
> because emulator file characteristics change from emulator to
> emulator and pc platform to platform, I want something that is
> common to all systems.
Emulators which support .z80 and .tap files are far more common than
those which support reading direct sound input.
More seriously, as long as the format you've got the files in is
non-proprietary, it doesn't really matter what format it's in as you can
always convert it from one to another (as you're happily proving here).
> Thank you all for hearing me out. Any ideas and/or suggestions
> would be welcome.
http://www.worldofspectrum.org/soundload.html#back
Cheers,
Phil
--
"Nah, she's a girl, right? Making boys crazy is like your job
description."
Mike: Buffy: Help
3. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
Bruno Florindo · Tue, 21 Sep 2004 16:33
Hi. For tap files I use the tap plugin for winamp. It will play your tap files and you can save it in any format using the system mixer, or save it to tape using line out.
----- Original Message -----
From: hatulzabad
To: [email]
Sent: Thursday, September 16, 2004 8:11 AM
Subject: [ts2068] CDs as a storage device -- my successes and failures thus far
I have recently acquired a pc with the ability to burn CD-ROMs
and have been experimenting with the idea of saving my library of
Timex/Sinclair 2068 and ZX Spectrum 48 tapes as sound files that
will reload into the original computers as if loading from a
cassette tape. For my first experiment, I saved the contents of a
cassette tape to a WAV file using Roxio. Using the Roxio sound
editor, I was able to partition each program so they would save as
separate bands on the CD-ROM. (I was even able to eliminate the
"kathunk" between programs where the tape had been started and
stopped.) I then saved my work as a music CD. Using this CD, I
was able to load the programs I had saved with the aid of a small
pre-amp. I was also able to skip directly to the program I wanted
from the CD without having to play through the entire CD. This
looked to be very promising except when I tried to do the same with
another tape, it was a total failure. The problem was that the
second tape was very dirty and, as yet, I am not enough of a sound
engineer to know which frequencies to boost or suppress to obtain
a cleaner tape. So the bottom line with this method is that the
chances of being able to burn a CD that will reload into a real
Sinclair computer depends upon the state of the original tape and
the ability to do a clean transfer from tape to CD.
After stewing a bit over my failure with the second tape, I began
to wonder why I could not convert the TAP files I had created with
Lunter's Z80 Spectrum emulator directly into sound files. This
would surly eliminate the hiss and rumble found on most cassette
tapes and greatly increase the chances of a successful load. I
used Lunter's TAP2VOC conversion utility in conjunction with
another utility to convert several TAPs into WAV files which I then
burned as a music CD. The result was I had a CD of beautifully
clean sound files but the files were compressed to such a degree
that they would not load into a real Sinclair computer. They
sounded like the game programs that required Hyperloader. However,
the VOC files I created and burned as data files reloaded
beautifully into Lunter's emulator even though they originated from
a CD. Still, the VOC files were in a compressed state and could
not be played on a standard CD player or reloaded into a real
Sinclair computer. If I hope by this method to have a CD that will
load into a real Sinclair computer, I need to find a way to
decompress the VOC files to a point that they can be recognized by
the original computers.
Some of you may be wondering why I am going to all this trouble
to create sound files when I could just as easily save emulator
MDR, TAP, Z80 and suchlike files. The reason is that I would want
files that will reload into the original computers. The second
reason is because emulator file characteristics change from
emulator to emulator and pc platform to platform, I want something
that is common to all systems.
Thank you all for hearing me out. Any ideas and/or suggestions
would be welcome.
David Solly
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4. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
Johnny Red · Wed, 22 Sep 2004 01:08
Have you checked the bit rate of the VOC file?
VOC files usually have 22222 bits/s and CD uses 44100 bits/s
That might be the problem with what you call "compressed VOC files".
This because you wrote that it look like it was a HyperLoader block. It
was playing too "fast" (about twice as fast).
Johnny Red, Portugal
On Thursday, September 16, 2004, at 04:11 PM, hatulzabad wrote:
> After stewing a bit over my failure with the second tape, I began
> to wonder why I could not convert the TAP files I had created with
> Lunter's Z80 Spectrum emulator directly into sound files. This
> would surly eliminate the hiss and rumble found on most cassette
> tapes and greatly increase the chances of a successful load. I
> used Lunter's TAP2VOC conversion utility in conjunction with
> another utility to convert several TAPs into WAV files which I then
> burned as a music CD. The result was I had a CD of beautifully
> clean sound files but the files were compressed to such a degree
> that they would not load into a real Sinclair computer. They
> sounded like the game programs that required Hyperloader. However,
> the VOC files I created and burned as data files reloaded
> beautifully into Lunter's emulator even though they originated from
> a CD. Still, the VOC files were in a compressed state and could
> not be played on a standard CD player or reloaded into a real
> Sinclair computer. If I hope by this method to have a CD that will
> load into a real Sinclair computer, I need to find a way to
> decompress the VOC files to a point that they can be recognized by
> the original computers.
5. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
Fred · Wed, 22 Sep 2004 11:54
Hi David,
Is your desktop/notebook computer anywhere near your Sinclair? I load
programs from TZX tape image files directly to my TC2048 by plugging the
sound output from my Mac into my TC2048, turning the volume up and using
the playtzx program (available from <http://www.worldofspectrum.org>).
You can find other similar programs (winamp plugins etc.) as well as
utilities to convert .TAP files to .TZX files there. This saves you
messing about with real media, and allows you to access you whole
library directly.
If you are dead set convinced you need to make physical media, playtzx
can also write a .VOC file at the correct sampling rate for CDs
(44.1KHz). I am sure the winamp plugin can also do this.
You can also find utilities to turn .z80 etc. snapshot files into very
fast loading tape images (z802tzx, snap2tzx) that could not be supported
with tape media at all. These files can then be reloaded into a real
machine with the playtzx program etc. above.
hatulzabad wrote:
> So the bottom line with this method is that the
> chances of being able to burn a CD that will reload into a real
> Sinclair computer depends upon the state of the original tape and
> the ability to do a clean transfer from tape to CD.
There are programs that will analyse a tape sample and convert it to a
.TZX tape image file, applying various filters to clean up dirty
samples. Look for maketzx and taper at the WoS website above.
> After stewing a bit over my failure with the second tape, I began
> to wonder why I could not convert the TAP files I had created with
> Lunter's Z80 Spectrum emulator directly into sound files. This
> would surly eliminate the hiss and rumble found on most cassette
> tapes and greatly increase the chances of a successful load. I
> used Lunter's TAP2VOC conversion utility in conjunction with
> another utility to convert several TAPs into WAV files which I then
> burned as a music CD. The result was I had a CD of beautifully
> clean sound files but the files were compressed to such a degree
> that they would not load into a real Sinclair computer. They
> sounded like the game programs that required Hyperloader.
Sounds like the .VOC to .WAV file converter you used messed up the
sample rate in conversion. The .VOC should be written at a 44.1KHz
sample rate if you want to use it for writing to a CD, and the converter
needs to understand that .VOC files with that rate (it is a newer
feature of the .VOC format, and not everything understands it).
> The second reason is because emulator file characteristics change from
> emulator to emulator and pc platform to platform, I want something
> that is common to all systems.
Just about all emulators support the .z80 and .tap formats. Any modern
emulator will support .TZX tape images. Fewer emulators support loading
directly from sound files than emulator formats.
HTH,
Fred
6. Re: CDs as a storage device -- my successes and failures thus far
Jeff · Thu, 23 Sep 2004 15:49
David;
A few of things:
1. The 2068 uses 2040Hz and 1020Hz pulses for storing data to tape
and 806.5Hz for synchronizing the software to the tape input. The
Z80 actually times the period between transitions to determine the
frequencies. Moreover, only one cycle of any particular frequency is
used. If you have sound software with a multiband equalizer or user
specified filter frequencies, you may be able set them to pass the
frequencies of interest and reject the rumble and hiss from the tape
machine. Wow and flutter could be irrelavant if the proper filter
cutoffs were selected.
2. I do not know how the various emulators emulate the tape input
conditioning circuitry in a real 2068, so there might be subtle
incompatiblities that allow some audio files to work with the
emulator and not with the real hardware, especially if the audio
files have been produced or processed by software.
3. There is a specific structure the 2068 writes to tape. See the
extract from the tech manual below. If the data structures are not
correct or the final transition in the audio file is not there, the
2068 probably will not accept the file as valid or may abort the tape
load.
4. It should be possible to write a Windows utility that could
process a WAV file using the specific parameters for a 2068 tape file
(a sort of adaptive filter/processor) to clean it up and recover the
data. The program could also be used to accept binary data and
output a WAV file that is compatible with the 2068.
I hope all of this helps in some way.
Here is an extract from the 2068 tech manual about the tape routines:
4.2 Cassette Tape
Tape I/O is done via Port OFEH. An I/O read of Port OFEH pulls in the
cassette input on Bit 6. An I/O write of Port OFEH Bit 3 controls the
tape output with Bit 3 = 1 genrating a high output and Bit 3 = 0
generating a low output. Data is written to the tape under software
control creating the following frequencies and format:
Sync Pattern of 4032 cycles at 806.5 Hz. (5 sec.)
Header: 17 bytes of data identifying the following data block as
either Program, Number Array, Character Array, or Binary Code and
containing other control information.
The header is written as Data, i.e. the Most Significant Bit first in
each byte, 1 cycle at 2040 Hz. for a Zero and 1 cycle at 1020 Hz. for
a One. The first byte is zero identifying the header. The final byte
is a Checksum calculated by XOR of all preceding data bytes.
Software delay of approximately 835 milliseconds. Sync Pattern of
1612 cycles at 806.5 Hz. (2 secs.)
Transition Pattern of 1 cycle at 2400 Hz. Data Block: Written as Data
(see above) with first byte
= -1 (FFH) and a final Checksum byte. Figure 4.2-l shows the header
formats for the various types of data.
The routines used to actually write and read the tape (W TAPE and R
TAPE) are in the TAPE Module of the Extension ROM (see map in
Appendix A). They are accessible via the Extension ROM Interface
Routine listed in Figure 3.2.2-2. The general flow required to write
a header and data block is:
1. Call W TAPE with A=O. IX contains the address of the header and DE
contains the length.
2. Delay loop approximately 1 second.
3. Call W TAPE with A=FFH. IX contains the address of the data block
and DE contains the
length.
The R TAPE routine performs either a LOAD (transfers data from tape
to memory) or VERIFY (compare data from tape against data in memory)
operation, based on the status at entry: Carry Set for Load and No
Carry if Verify. As for the Write, A=Block Type (0 for Header and -1
(FFH) for Data Block). IX contains the memory address.
The tape routines return Carry=1 for successful completion and No
Carry for error or Break Key detected, Roth W TAPE and R TAPE exit
via the routine W BORD which restores the Border color based on bits
3-5 of the system variable BORDCR. If the Break Key is detected
during this exit routine, a RESTART 8 (ERROR) is executed.
NOTE: The write to Port OFEH in the exit routine restoring the Border
Color has hit 3 = 0. This creates a final transition on the tape
followina a write ooeration. This transition is necessary in order to
successfully read back the final data bit from some tape recording
devices. If you are calling the W TAPE routine so as to bypass the
normal exit path, you must perform this final
write to Port OFEH with Bit 3 = 0 within a similar timeframe.
Addendum to R TAPE routine:
Register DE must contain the length of the-block to be read (DE=17
for the Header, and DE=HDLEN for Data). See Fig. 4.2-l for a
definition of HDLEN.
7. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
David Solly · Mon, 27 Sep 2004 12:00
Hello Bruno....
Where do I get this plug-in? Thanks.
David
----Original Message Follows----
From: "Bruno Florindo" <[email]>
Reply-To: [email]
To: <[email]>
Subject: Re: [ts2068] CDs as a storage device -- my successes and failures
thus far
Date: Tue, 21 Sep 2004 16:33:11 -0700
Hi. For tap files I use the tap plugin for winamp. It will play your tap
files and you can save it in any format using the system mixer, or save it
to tape using line out.
----- Original Message -----
From: hatulzabad
To: [email]
Sent: Thursday, September 16, 2004 8:11 AM
Subject: [ts2068] CDs as a storage device -- my successes and failures
thus far
I have recently acquired a pc with the ability to burn CD-ROMs
and have been experimenting with the idea of saving my library of
Timex/Sinclair 2068 and ZX Spectrum 48 tapes as sound files that
will reload into the original computers as if loading from a
[Snip!!!]
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8. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
Bruno Florindo · Fri, 8 Oct 2004 18:23:
from here.
http://winamp.com/plugins/details.php?id86&download=yes&url=http%3A%2F%2Fdownload.nullsoft.com%2Fcustomize%2Fcomponent%2F2000%2F3%2F5%2FP%2Ftap_player.exe
Cheers.
----- Original Message -----
From: "David Solly" <[email]>
To: <[email]>
Sent: Monday, September 27, 2004 9:00 AM
Subject: Re: [ts2068] CDs as a storage device -- my successes and failures
thus far
>
>
> Hello Bruno....
>
> Where do I get this plug-in? Thanks.
>
> David
>
>
> ----Original Message Follows----
> From: "Bruno Florindo" <[email]>
> Reply-To: [email]
> To: <[email]>
> Subject: Re: [ts2068] CDs as a storage device -- my successes and failures
> thus far
> Date: Tue, 21 Sep 2004 16:33:11 -0700
>
> Hi. For tap files I use the tap plugin for winamp. It will play your tap
> files and you can save it in any format using the system mixer, or save it
> to tape using line out.
> ----- Original Message -----
> From: hatulzabad
> To: [email]
> Sent: Thursday, September 16, 2004 8:11 AM
> Subject: [ts2068] CDs as a storage device -- my successes and failures
> thus far
>
>
> I have recently acquired a pc with the ability to burn CD-ROMs
> and have been experimenting with the idea of saving my library of
> Timex/Sinclair 2068 and ZX Spectrum 48 tapes as sound files that
> will reload into the original computers as if loading from a
>
> [Snip!!!]
>
> _________________________________________________________________
> Take charge with a pop-up guard built on patented Microsoft® SmartScreen
> Technology
>
http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID94&DI34&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines
> Start enjoying all the benefits of MSN® Premium right now and get the
> first two months FREE*.
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
9. Re: [ts2068] CDs as a storage device -- my successes and failures thus far
joe schmoe · Sun, 24 Oct 2004 18:31
Great Job Keep up the good work David.
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