🚀 go-pugleaf

I have a Media Vision Pro audio spectrum Sound Card (PAS)
A microphone plugs into the PAS and it records whatever.
A Guitar can be  recorded, a radio, a CD ,or a cassette player. 
 Its uses a standard stereo jack.
There are several  different speeds and sound compression settings.
A One minute recording of  Guns & Roses uses 50-200Kb disk space
depending on compression.
A cassette could easily be plugged into the card and the data on the
magnetic tape transferred  right onto to a Hard Disk. 

From this point the technology gets simpler. 
There are available Mass data storage Cassettes for Computers that
hold 250-500 Mb. 
They are used to D/L data off the Hard drive and store on a cassette
tape still accessable to the computer just slower reading when the
tape fills up plug in another one.
They are used to  backup the Hard drives data. Set a tape for backup
in the evening, come back in the morning and its done. It takes
several hours to copy a Gigabyte.

The Tapes have to be read from beggining to end because of the design.
The hard drive has added movable reading heads for quicker access to
data.
The cassette has a moveable tape no movable sensors.
 Front to back & back to front.
IBM and others are constantly experimenting with data storage in
different forms . 
They can even save tiny pictures of words and letters to be read and
its on a tape. A sound graph would be simple.
Problems:
1) can't sell old software. 
    If people can store and utilize old favorite software, who will
support  Microsoft.
2 Computer opersting systems are always changing. Hence you buy
hardware, software, and Blue sky If things settle down and stabilize
you can't have your pocket picked 
More Later 
Hammer

Bloody heck, my newsreader won't let me kill this article!

Oh well.  I realized immediately after sending that no work is required at 
all -- who cares if you can decode the data stream on a PC.  

What's important is that you can capture cassette output to a .WAV file 
(or whatever) via the microphone in jack on a PC sound card, then play it 
back any time you like, even trade the sound files with other owners.

That said, does anyone have Sinclair ZX-81/TS-1000 games they'd like to 
capture and send me or upload to an archive? :)

  -Dorian

In article <4etnnl$4fj@news.microsoft.com>, doriang@microsoft.com says...
>
>{Forgive me if this has already been addressed in a FAQ somewhere...}
>
>So we've got dozens of old relics that have nothing to save/load data 
>to/from but a cassette tape recorder.
>
>Now, note that a PC clone with a cheap sound card can generate and 
capture 
>audio signals.
>
>Proposal: Is it possible to write an app that could capture programs & 
>data from an old computer's cassette interface via a sound card?  If so, 
>could it be architected to accomodate all popular data formats and so 
that 
>people could add new formats as they're discovered?
>
>The benefits are obvious: greater reliabilty, limitless, random access, 
>and greater ease in trading/distributing/archiving legacy code for old 
>hobbyist platforms.  Also, those old cassette tapes are losing their bits 
>with every passing year!
>
>Would anyone want to take this on with me?
>
>  -Dorian
>

-- 
The opinions expressed in this message are my own personal views 
and do not reflect the official views of Microsoft Corporation.

I don't have any old computers so I can't trade programs with you.

good idea for using a current PC.

The other thing you could do it bypass the tape / audio circuitry
altogehter and wire up something to hood directly up to a parallel
port. the interface is easy, and you could bypass all the sound
issues. 

Either way is propably equally simple, just depends on your experience
and background.



doriang@microsoft.com (Dorian Garson) wrote:

>Bloody heck, my newsreader won't let me kill this article!

>Oh well.  I realized immediately after sending that no work is required at 
>all -- who cares if you can decode the data stream on a PC.  

>What's important is that you can capture cassette output to a .WAV file 
>(or whatever) via the microphone in jack on a PC sound card, then play it 
>back any time you like, even trade the sound files with other owners.

>That said, does anyone have Sinclair ZX-81/TS-1000 games they'd like to 
>capture and send me or upload to an archive? :)

>  -Dorian

>In article <4etnnl$4fj@news.microsoft.com>, doriang@microsoft.com says...
>>
>>{Forgive me if this has already been addressed in a FAQ somewhere...}
>>
>>So we've got dozens of old relics that have nothing to save/load data 
>>to/from but a cassette tape recorder.
>>
>>Now, note that a PC clone with a cheap sound card can generate and 
>capture 
>>audio signals.
>>
>>Proposal: Is it possible to write an app that could capture programs & 
>>data from an old computer's cassette interface via a sound card?  If so, 
>>could it be architected to accomodate all popular data formats and so 
>that 
>>people could add new formats as they're discovered?
>>
>>The benefits are obvious: greater reliabilty, limitless, random access, 
>>and greater ease in trading/distributing/archiving legacy code for old 
>>hobbyist platforms.  Also, those old cassette tapes are losing their bits 
>>with every passing year!
>>
>>Would anyone want to take this on with me?
>>
>>  -Dorian
>>

>-- 
>The opinions expressed in this message are my own personal views 
>and do not reflect the official views of Microsoft Corporation.


Chris Cothrun
cothrun@ix.netcom.com
Ingenuity Inc.

Now for the worst part of this, potential nightmere.
The famous C64(Commodore,TI,Timex,Sinclair,Atari-64) 
or just C-64 (64 Kb) can be emulated by an IBM clone with a DOS
program, I'll get the D/L for all of you next time I hit alt.bin.c64s 

Also available, are 100's of old C64 games to go with the C64
emulator. The games are as great as they were twenty years ago.
Thats the problem, we continue to become more sophisticated in our
games, with Megabytes strewn about here and there. 
Now a days Those old games are just old games.

	 If you can fool a IBM into thinking its a C64 its going to
develop problems later on in life with co-dependency, low self esteem,
and probably start hanging with a bad bunch of chips. Get a computer
starded on drugs and they will burn up. 
I rue the day a Packard-Bell shows up alone in Warez with your Word
processing software.
Imagine being blackmailed by a Toshiba, that is threatening to Upload
your financial records to some, silicon babe, at Microsoft, for a few
measly bytes of RAM.
 Sad Sad Sad to see the seedier side of silicon life. 
Then we have increased social unrest, and created another minority
group to kick around(Hey! not to bad an idea). I was getting tired of
picking on Russians, and Germans, and Africans. (maybe not the krauts,
I still give them a hard time). There is nothing more heart rending
than a computer family with young ones out on the streets, stealing,
Begging, Pan handling.
 We have all seen it before, don't pretend.
I get rid of them by acting like I can't tell a CPU from a tower.
or forget their names and call a 486 a 286.
That hurts the little Silicon dirt balls. I mean, what the hell, its
only a piece of quartz a common rock. Right, well am I right.

Shit, then the Welfare crap starts, riots, chips against magnetic
discs.
Magneto-Optical's give me a pain they think they are so superior, then
in a short 18 months they are on the bottom of the heap, Bragging on
the good old days, last year.

Even a Dip switch won't feel safe.
The most hypocritical is that you thought it was a good idea.
Do you really care when  you destroy the life of these little
creatures. Just so you can get your jollies off playing PONG.   

		     'nuff said with that there 

Maybe too much said,  but I hate these little crystaline cretins. We
should take them all out, to the woods, hook wires up to them and turn
on the juice. 
		"Thats my solution
				to the silicon wafer revolution"

I don't want a family of those creaps living next to me.
Later 	
Hammer

  

In article <4etnnl$4fj@news.microsoft.com> doriang@microsoft.com (Dorian Garson) writes:
>{Forgive me if this has already been addressed in a FAQ somewhere...}
>
>So we've got dozens of old relics that have nothing to save/load data 
>to/from but a cassette tape recorder.
>
>Now, note that a PC clone with a cheap sound card can generate and capture 
>audio signals.
>
>Proposal: Is it possible to write an app that could capture programs & 
>data from an old computer's cassette interface via a sound card?  If so, 
>could it be architected to accomodate all popular data formats and so that 
>people could add new formats as they're discovered?
>
>The benefits are obvious: greater reliabilty, limitless, random access, 
>and greater ease in trading/distributing/archiving legacy code for old 
>hobbyist platforms.  Also, those old cassette tapes are losing their bits 
>with every passing year!
>
>Would anyone want to take this on with me?
>
>  -Dorian
>
Hmmm...  Someplace I think that I have the schematics for the
Kansas City Standard Casette interface.  I think that that was
the interface that most micros of the late 70s used.  The
actual format in which the programs were stored varied from
machine to machine.  Some machines stored the actual keystrokes
so that loading a tape was just like typing it in at 300 characters
per second.  Others stored interpreter codes (assuming you're
loading a BASIC program).  Some, like the TRS-80 I think, could
also directly load hex from tape.

Hi,
The Technique of copying Magnetic Tape data, to a higher density
storage media, like a magnetic disk was first applied over Ten years
ago by that glorious man "Thomas I. Sinclair" inventor esquisite.
Why,George is credited with creating and marketing the modern door
stop. Millions of these very expensive door stops were purchased in
America.  

Rings up a few ghosts in my my closet
Hammer

Hammer (Hammer@cyber.sp.ace) wrote:
: Hi,
: The Technique of copying Magnetic Tape data, to a higher density
: storage media, like a magnetic disk was first applied over Ten years
: ago by that glorious man "Thomas I. Sinclair" inventor esquisite.
: Why,George is credited with creating and marketing the modern door
: stop. Millions of these very expensive door stops were purchased in
: America.  

: Rings up a few ghosts in my my closet
: Hammer

What *IS* this person babbling about?
--
______________________________________________________________________________
| 			|What to do if you find yourself stuck in a crackin  |
|u5a77@cc.keele.ac.uk	|the ground beneath a giant bolder, which you can't  |
|			|move, with no hope of rescue.			     |
|Andrew Halliwell	|Consider how lucky you are that life has been good  |
|Principal in:-		|to you so far... 				     |
|Comp Sci & Visual Arts	|	-The BOOK, Hitchhikers guide to the galaxy.  |
------------------------------------------------------------------------------

doriang@microsoft.com (Dorian Garson) writes:

>So we've got dozens of old relics that have nothing to save/load data 
>to/from but a cassette tape recorder.

>Now, note that a PC clone with a cheap sound card can generate and capture 
>audio signals.

>Proposal: Is it possible to write an app that could capture programs & 
>data from an old computer's cassette interface via a sound card?

The TRS-80 Model 1 Emulator for PCs, written by Jeff Vavasour, comes with
some utility programs which can read and write TRS-80 tapes using a
Soundblaster-compatible sound card.

You can find a shareware version of the TRS-80 Model 1 emulator at the FTP
site: oak.oakland.edu.  The file is under: simtel/msdos/emulator/model1-d.zip.
I don't remember if the shareware version has the cassette support software;
you may have to register -- it's quite cheap -- to get those utilities.
You'll certainly need to register to get their source code.

- David Librik
librik@cs.Berkeley.edu

On Sat, 3 Feb 1996, Hammer wrote:

> Hi,
> The Technique of copying Magnetic Tape data, to a higher density
> storage media, like a magnetic disk was first applied over Ten years
> ago by that glorious man "Thomas I. Sinclair" inventor esquisite.
> Why,George is credited with creating and marketing the modern door
> stop. Millions of these very expensive door stops were purchased in
> America.  


Wow.... You're an Idiot.

What happens when I press this button.   Oh a tag line
 Andy 
afn09039@freenet.ufl.edu

Hammer@cyber.sp.ace (Hammer) wrote:
>I have a Media Vision Pro audio spectrum Sound Card (PAS)
>A microphone plugs into the PAS and it records whatever.
>There are several  different speeds and sound compression settings.
>A One minute recording of  Guns & Roses uses 50-200Kb disk space
>depending on compression.
>A cassette could easily be plugged into the card and the data on the
>magnetic tape transferred  right onto to a Hard Disk. 
>
How about trying the reverse of this. Write a program to produce the 
right frequency sounds on your sound card. Then download programs for 
say, the C64, and write those programs to a cassette tape using your 
sound card program. If this works correctly, the C64 shoudl be able to 
read the tape. Viola!!! You've got it. (PS, I *know* viola is *not* the 
right word--that is an *intentional* malapropism for the sake of humor.)

[I'm reading this in comp.sys.sinclair]

In article <4etnnl$4fj@news.microsoft.com>, Dorian Garson (doriang@microsoft.com) wrote:
: {Forgive me if this has already been addressed in a FAQ somewhere...}

  Well, the comp.sys.sinclair FAQ isn't posted regularly so I think you can
be forgiven by css at least.

: So we've got dozens of old relics that have nothing to save/load data 
: to/from but a cassette tape recorder.

  Not _quite_ true; the Spectrum can have add-on 3.5" disc drives and write
to DOS discs. And a genuine Spectrum can read ZX81 tapes (I've done it). But
yes, most people would only have cassette capability.

: Now, note that a PC clone with a cheap sound card can generate and capture 
: audio signals.

: Proposal: Is it possible to write an app that could capture programs & 
: data from an old computer's cassette interface via a sound card?

  It has been done for Sinclair machines, using the Z80 and PJPP emulators
 - look in <ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/>. However, a sound
card is not very well suited for computer data signals, and Z80 prefers to
use a dedicated tape interface. Since very few of us still have original IBMs 
with the tape interface, this is mostly done by building a small adaptor and 
plugging it into the LPT1 socket. See Z80.DOC for details.

:  If so, could it be architected to accomodate all popular data formats and
: so that people could add new formats as they're discovered?

  Z80 emulates a real Spectrum very accurately, and can read just about any
Spectrum cassette format (though sometimes the data have to be saved as vast
VOC files). I don't know how many other formats it could be 
persuaded to read though.
  
: The benefits are obvious: greater reliabilty, limitless, random access, 
: and greater ease in trading/distributing/archiving legacy code for old 
: hobbyist platforms.

  A lot of this has been done for Sinclair machines;
<ftp://ftp.nvg.unit.no/pub/sinclair> holds mostly legally-distributable 
software.

(+Rant)It's a pity the rest of Microsoft doesn't share this attitude towards
old hobbyist platforms; making their 8-bit programs freeware (as Hitech have
done with Hitech C) would be a very fine gesture.(-Rant)

--------------------------- 
John Elliott              | \o_~^~                     \|/      _o  \|/
CHAOS in a sig...         |  |                       ==@V        |\  V
--------------------------- /| _,_                 _//\\|.       A  .|.

In article <4eu4mo$gff@news.microsoft.com> doriang@microsoft.com (Dorian Garson) writes:
>Bloody heck, my newsreader won't let me kill this article!
>
>Oh well.  I realized immediately after sending that no work is required at 
>all -- who cares if you can decode the data stream on a PC.  
>
Yea, but if you don't decode it, it's likely to get pretty big.
Most PCM style recordings do get pretty big.  It would be interesting
to investigate the hardware and see just what you could get away
with in terms of sampling rates, etc.  Also, being able to decode
the tapes might make it possible to restore programs where sections
of the tape have become illegible.  Most of the old machines aborted
when they hit an error.  If you could write a PC program to load
the whole tape, you could probably correct most one character
errors, or maybe use two corrupted copies to fill in the gaps
that each has.  You could also clean up a marginal recording,
maybe the tape has stretched some and the frequency shifts a little.
You could make the program smart enough to detect and correct these
problems and produce a "perfect" program tape.

In article <4f3025$hmf@hecate.umd.edu>, bill@umsa7.umd.edu (Bill Sudbrink) writes:
|> In article <4eu4mo$gff@news.microsoft.com> doriang@microsoft.com (Dorian Garson) writes:
|> >Bloody heck, my newsreader won't let me kill this article!
|> >
|> >Oh well.  I realized immediately after sending that no work is required at 
|> >all -- who cares if you can decode the data stream on a PC.  
|> >
|> Yea, but if you don't decode it, it's likely to get pretty big.
|> Most PCM style recordings do get pretty big.  It would be interesting
|> to investigate the hardware and see just what you could get away
|> with in terms of sampling rates, etc.  Also, being able to decode
 

	I have already been successful in doing this with a TI-99/4A computer
The quality of the recording need not be great, The computer is happy with
8Khz, mono recordings.  If you use ADPCM modulation in recording the WAV file
you can get acceptable program sizes of about 150K or so.
	I use the following procedure to get the best recording....
	1. Load program to TI from tape
	2. "Record" the output of the save back to tape to my soundblaster.
You should not do too many in a row, because the circuits used to generate
the recordable signal seems to be flaky(at least on mine-the gain drops rapidly
when the circuits are too hot...)  Also, I had a problem with hum which was solved
by grounding the case of the IBM to the shield of the TI(it is more convenient to
attach a ground wire to one of the shield screws internally--only attempt this if
you feel confident in openeing the case!)  One final step to reduce noise is to
shut off the monitor attached to the TI if it is _directly_ connected (ie. not
using the modulator) If you use a TV, just keep it a good distance from the TI.

Finally, I used cool edit to record with.... Good luck



				--Patrick

doriang@microsoft.com (Dorian Garson) writes:

> {Forgive me if this has already been addressed in a FAQ somewhere...}
> 
> So we've got dozens of old relics that have nothing to save/load data 
> to/from but a cassette tape recorder.
> 
> Now, note that a PC clone with a cheap sound card can generate and capture 
> audio signals.
> 
> Proposal: Is it possible to write an app that could capture programs & 
> data from an old computer's cassette interface via a sound card?  If so, 
> could it be architected to accomodate all popular data formats and so that 
> people could add new formats as they're discovered?
> 
> The benefits are obvious: greater reliabilty, limitless, random access, 
> and greater ease in trading/distributing/archiving legacy code for old 
> hobbyist platforms.  Also, those old cassette tapes are losing their bits 
> with every passing year!
> 
> Would anyone want to take this on with me?

It's already been done to some extent for the TRS-80 model I (and
possibly model III). 

Unfortunately, I don't have a "normal" sound card, just the (pretty
decent) sound hardware built into this Tandy 1000 TL/3. So I have to
write my own software anyway.

Given that there *are* different interfaces to various sound hardware,
I think we need to break the problem down into sections:

1. document the various cassette formats
2. come up with software to read one of the standard sampled sound
   formats (*.WAV?) and interpret it according to one of the formats. 

It might even be a thought to define our own sample format. It'd have
to be an uncompressed format, but at the same time, we probably don't
need to save the "normal" sort of dynamic range info. 

In any case, I do think it's best to have software that translates
sound files to program or data files rather than having them go direct
from the sound card to the program/data file. That way it doesn't
matter *what* you got the data into a sound fuile with, just that you
*did*. 

I think the highest bit rate of any of the old cassette formats was
2400 bps or so. That means that we need a sample rate *considerably*
higher so we can be sure to filter out sampling artifacts, and catch
the (very distorted!) waveforms. 8 times higher is probably overkill,
but that is only 19,200 Hz. So 22khz sampling ought to do it. If I'm
remembering wrong and the highest rate is 1500 bps (used in the TRS-80
Model III/4, CoCo, and Model 100/102/200) then we could even manage
with 11 khz (unless I've overlooked something).

I know of the following formats: 

bps	System
------	--------------------------
250	*TRS-80 Model I/III Level 1
500	*TRS-80 Model I Level 2
1500	*TRS-80 Model III
1500	*TRS-80 Color Computer (all models), Micro Color Computer
1500	*TRS-80 Model IV, 100, 102, 200
1200	*"Kansas City Standard"
????	Apple II
????	Pet 2001
????	Vic-20 (may not be readable on standard casstte recorder)
????	C-64   (may not be readable on standard casstte recorder)
????	Atari 8-bit systems
????	IBM-PC
????	Sinclair (various models, do they all use the same format?)

* = I have docs of the format buried *somewhere* in storage

BTW, the Tandy formats are all actually a "protocol" format, and there
are multiple file types encoded with that protocol (BASIC programs,
data files, machine language executables, etc). But if you can do the
"protocol" you can get the files as a stream of bytes, suitable for
feeding to an emulator. Converting them further is an excercise for the
programmer who wants to do the extra work (but worth it for getting
programs and data extracted to use with other systems)


Leonard Erickson 		(aka Shadow)
 shadow@krypton.rain.com	(preferred)	
leonard@qiclab.scn.rain.com	(last resort)

doriang@microsoft.com (Dorian Garson) wrote:
>

> Proposal: Is it possible to write an app that could capture programs & 
> data from an old computer's cassette interface via a sound card?  

I remember reading in an old Pirate's Handbook that duplicating 
Commodore tapes by Audio means was very unreliable. To get a reliable
copy, you had to load the program and save it back out, and that only
worked for unprotected software. I can't help but wonder if an audio
readout from tape to a sound card would not suffer from the same
problem.

In article <4f5cej$ql2@charnel.ecst.csuchico.edu>,
Phil Hoff  <phoff@ecst.csuchico.edu> wrote:
>doriang@microsoft.com (Dorian Garson) wrote:

>> Proposal: Is it possible to write an app that could capture programs & 
>> data from an old computer's cassette interface via a sound card?  

>I remember reading in an old Pirate's Handbook that duplicating 
>Commodore tapes by Audio means was very unreliable. To get a reliable
>copy, you had to load the program and save it back out, and that only
>worked for unprotected software. I can't help but wonder if an audio
>readout from tape to a sound card would not suffer from the same
>problem.

I think they were probably referring to a tape to tape copy:  play tape
in one recorder and record on another recorder.  Commodores used a special
tape recorder optimized for their computers.  Run of the mill tape
recorders (used for the tape to tape copy) probably didn't give you a good 
enough SNR to reliably copy.  The Spectrum, on the other hand, has an
excellent tape interface designed for common tape recorders; it can
tolerate quite a bit of noise, so a tape to tape copy was fairly reliable.

The sound card recording is as good as a CD recording (16 bit sound cards
anyway) and much better than a tape recording.  If the original tape loads
fine, the sampled one will also work fine.  Loading via sound card is 
already implemented in a number of Spectrum emulators.

Alvin

Phil Hoff (phoff@ecst.csuchico.edu) wrote:

: I remember reading in an old Pirate's Handbook that duplicating 
: Commodore tapes by Audio means was very unreliable. To get a reliable
: copy, you had to load the program and save it back out, and that only
: worked for unprotected software. I can't help but wonder if an audio
: readout from tape to a sound card would not suffer from the same
: problem.

Well, I dunno about using a sound card, but one of the Cosiners has made up
a transfer system that can read C64 tape signals (saved with his own tape
loader) and transfer them to an Amiga via a sampler.  But he has also
managed to make the Amiga emulate the same tape signal so that he can
write (different) files back to tape by recording the Amiga's sound output
and loading it back in at the C64 end!

Can't see why it won't work with a sound card!
(Slight PS, it is possible to copy tapes with audio decks, but its best to
use mono decks (like the ones people used to use with Spectrums).  If
possible its better to get two datasette's and a doubler!)

Jason  =-)

On Sat, 3 Feb 1996, Hammer wrote:

> Now for the worst part of this, potential nightmere.
> The famous C64(Commodore,TI,Timex,Sinclair,Atari-64) 
> or just C-64 (64 Kb) can be emulated by an IBM clone with a DOS
> program, I'll get the D/L for all of you next time I hit alt.bin.c64s 

Can't anybody make this bloke just shut up....

Nele

>   ????	Vic-20 (may not be readable on standard casstte recorder)
>   ????	C-64   (may not be readable on standard casstte recorder)

Should be readable. There was a kit I remember from a few years ago to
use a `normal' cassette machine with the VIC/C64. The only difference
with the Commodore version was a fixed record/replay level. I can find
out the VIC/C64 pinout for the cassette port if you like.

>   ????	Atari 8-bit systems

These also used a proprietry records, but I imagine that what I said
for Commodore also applies here.

>   ????	IBM-PC

Not much point? How much was available on tape?

>   ????	Sinclair (various models, do they all use the same format?)

I think the ZX80/81/Spectrum used the same encoding.

--

----------------------------------------------------------------------------
Robert Manners                                  Osney Laboratory
rjm@swift.eng.ox.ac.uk                          Dept of Engineering Science
                                                University of Oxford
                                                01865 288762
Computer Museum: http://swift.eng.ox.ac.uk/rjm/museum.html
Also:            http://swift.eng.ox.ac.uk

      "There's more to life than books you know, but not much more"
----------------------------------------------------------------------------

Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:

: >   ????	Vic-20 (may not be readable on standard casstte recorder)
: >   ????	C-64   (may not be readable on standard casstte recorder)

: Should be readable. There was a kit I remember from a few years ago to
: use a `normal' cassette machine with the VIC/C64. The only difference
: with the Commodore version was a fixed record/replay level. I can find
: out the VIC/C64 pinout for the cassette port if you like.

: >   ????	Atari 8-bit systems

: These also used a proprietry records, but I imagine that what I said
: for Commodore also applies here.

: >   ????	IBM-PC

: Not much point? How much was available on tape?

: >   ????	Sinclair (various models, do they all use the same format?)

: I think the ZX80/81/Spectrum used the same encoding.

ZX81.. No header and 300 BAUD
ZX Speccy Header and 1200 BAUD

I'd say they where different formats.
(Can't comment on the ZX80 though)
--
______________________________________________________________________________
| 			|What to do if you find yourself stuck in a crackin  |
|u5a77@cc.keele.ac.uk	|the ground beneath a giant bolder, which you can't  |
|			|move, with no hope of rescue.			     |
|Andrew Halliwell	|Consider how lucky you are that life has been good  |
|Principal in:-		|to you so far... 				     |
|Comp Sci & Visual Arts	|	-The BOOK, Hitchhikers guide to the galaxy.  |
------------------------------------------------------------------------------

rjm@swift.eng.ox.ac.uk (Bob Manners) writes:


>>   ????	Vic-20 (may not be readable on standard casstte recorder)
>>   ????	C-64   (may not be readable on standard casstte recorder)

>Should be readable. There was a kit I remember from a few years ago to
>use a `normal' cassette machine with the VIC/C64. The only difference
>with the Commodore version was a fixed record/replay level. I can find
>out the VIC/C64 pinout for the cassette port if you like.

I designed an interface like that when I got my first (second-hand) PET. 
It works with a Tandy CCR82 (I think) cassette recorder, and even 
correctly handles the play-button-pressed signal without mods to the 
recorder or the PET. I'll dig out the circuit sometime if anybody wants it.

>>   ????	IBM-PC

>Not much point? How much was available on tape?

That's surely the easiest machine to transfer tape to PC disk for, isn't 
it. All you need is an original PC motherboard, and a standard disk 
controller and video card. Then a bit of simple software to call the 
relevant BIOS routines to read the tape and write it to disk.

>Robert Manners                                  Osney Laboratory



--
-tony
ard12@eng.cam.ac.uk
The gates in my computer are AND,OR and NOT, not Bill

In article <RJM.96Feb7174404@swift.eng.ox.ac.uk>, Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:

: >   ????	Sinclair (various models, do they all use the same format?)

: I think the ZX80/81/Spectrum used the same encoding.

  I'm sorry to say you're wrong. I've no idea what the ZX80 used, but the ZX81
uses something at about 250 baud, and the Spectrum runs at about 1500 baud.
The Spectrum system works by detecting the time between voltage level 
changes, rather than the levels themselves. 

   The tape signals produced by the standard ROM have the following form:
     * A leader tone, five seconds long for a header block, two seconds
       long for a data block;
     * A sync pulse, to denote the end of the leader tone;
     * A series of 0 or 1 bits.

Leader tone:
     ____      __
    |    |    |    Each edge is separated by 619.4us
____|    |____|                      (2168 T-states).

Sync pulse:
   ___
  |   |            The first edge comes after 190.6us (667T);
__|   |            the second after a further 210us (735T).

Zero bit:
    ___
   |   |           Each edge is separated by 244.3us (855T).
___|   |

One bit:
     ____
    |    |         Each edge is separated by 488.6us (1710T).
____|    |


--------------------------- 
John Elliott              | \o_~^~                     \|/      _o  \|/
CHAOS in a sig...         |  |                       ==@V        |\  V
--------------------------- /| _,_                 _//\\|.       A  .|.

   Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:

     I think the ZX80/81/Spectrum used the same encoding.

   elliott@teaching.physics.ox.ac.uk  (John Elliott) writes:

     I'm sorry to say you're wrong. I've no idea what the ZX80 used,
   but the ZX81 uses something at about 250 baud, and the Spectrum runs 
   at about 1500 baud. The Spectrum system works by detecting the time 
   between voltage level changes, rather than the levels themselves. 


Wouldn't be the first time I was wrong! I thought the Speccy could
read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
unlikely for Sinclair to do this though ...

Cheers,
Bob.

--

----------------------------------------------------------------------------
Robert Manners                                  Osney Laboratory
rjm@swift.eng.ox.ac.uk                          Dept of Engineering Science
                                                University of Oxford
                                                01865 288762
Computer Museum: http://swift.eng.ox.ac.uk/rjm/museum.html
Also:            http://swift.eng.ox.ac.uk

    This message brought to you from an entirely Microsoft free system. 
----------------------------------------------------------------------------

In article <RJM.96Feb8133827@swift.eng.ox.ac.uk>, Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:

: Wouldn't be the first time I was wrong! I thought the Speccy could
: read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
: unlikely for Sinclair to do this though ...

  It _can_ read ZX81 tapes; since the processors run at the same speed and the
hardware's very similar, you just copy the relevant ZX81 ROM code into the 
Spectrum and away you go. This only loads the program as a raw memory dump,
but you get the data. I've written a program to do this, which works fine on
my real Spectrum, but no-one seems able to get it to work on an emulator.

--------------------------- 
John Elliott              | \o_~^~                     \|/      _o  \|/
CHAOS in a sig...         |  |                       ==@V        |\  V
--------------------------- /| _,_                 _//\\|.       A  .|.

Hello:

	I think that you're right till a certain point. It will work indeed,
but is like a deck copy (a copy from tape to tape): with each copy you're
increasing the level of noise...it will be better if it was decoded and
saved afresh!

	I have done in a PC a routine that reads Spectrum tapes and creates
a .TAP file in a disk (a binary image of the contents of the tape, already
translated). Apart for the little space it uses (compared to .WAV), I
think it's easier to manipulate. (at least for my emulation -- still in a 
early state).

	It has it's only problems, but I am considering to put it as GNU or
something like that... to see if other people are interessed in picking were
I left.

	It reads from printer port and from a SoundBlaster: but it's still
some problems with noisy tapes.

		Bye,
		Rui Ribeiro


In article <4fbat8$lbk@dns.crocker.com>, Daniel Dee <daniel> writes:
> >Oh well.  I realized immediately after sending that no work is required at
> >all -- who cares if you can decode the data stream on a PC.
> 
> >What's important is that you can capture cassette output to a .WAV file
> >(or whatever) via the microphone in jack on a PC sound card, then play it
> >back any time you like, even trade the sound files with other owners.
> 
> Agreed.
> 
> I once wrote a VERY short machine language program that reads signal
> coming into the cassette-in port of an Apple 2, and then writes it
> back out to the cassette-out port.
> 
> While cassette-to-cassette audio copy is very unreliable, the above
> method is fairly reliable even for copy-protected tapes. After all,
> the computer has to be able to read the data off the cassette tape,
> what needs to be done is just take the bit that was just read and
> write it back out again.
> 
> I bet the same method will work on any sound card.
> 
> -- Daniel Dee (daniel@wigitek.com)
> 

Hello:

	I am not sure I agree with you. For me your ideia has the same 
problem as tape to tape copy: noise problems. What really is needed
is decoding the tape, and do a program to save again the thing in the 
tape, generating signal afresh. Someone wishes to comment that?

	I am developing now a Spectrum emulation, and I have been developing
a short program to decode Spectrum's tapes and write the binary contents in
.TAP files (shorter than .WAV files, of course). It still got its flaws 
(especialy with tape noise), but it's working. I am planing of releasing it
as GNU or something like that, if there people out there interested in
'fidling' with the program... (PC assembler sources).

	I have also read here in the conference that a guy wrote one
utility to save Spectrum's tapes...



In article <4fbat8$lbk@dns.crocker.com>, Daniel Dee <daniel> writes:
> >Oh well.  I realized immediately after sending that no work is required at
> >all -- who cares if you can decode the data stream on a PC.
> 
> >What's important is that you can capture cassette output to a .WAV file
> >(or whatever) via the microphone in jack on a PC sound card, then play it
> >back any time you like, even trade the sound files with other owners.
> 
> Agreed.
> 
> I once wrote a VERY short machine language program that reads signal
> coming into the cassette-in port of an Apple 2, and then writes it
> back out to the cassette-out port.
> 
> While cassette-to-cassette audio copy is very unreliable, the above
> method is fairly reliable even for copy-protected tapes. After all,
> the computer has to be able to read the data off the cassette tape,
> what needs to be done is just take the bit that was just read and
> write it back out again.
> 
> I bet the same method will work on any sound card.
> 
> -- Daniel Dee (daniel@wigitek.com)
> 

Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:
: Wouldn't be the first time I was wrong! I thought the Speccy could
: read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
: unlikely for Sinclair to do this though ...

Nope. They were totally incompatible.
Even the character sets were different (the character set started at '0' on
the ZX81. The Speccy had ascii characters.

--
______________________________________________________________________________
| 			|What to do if you find yourself stuck in a crackin  |
|u5a77@cc.keele.ac.uk	|the ground beneath a giant bolder, which you can't  |
|			|move, with no hope of rescue.			     |
|Andrew Halliwell	|Consider how lucky you are that life has been good  |
|Principal in:-		|to you so far... 				     |
|Comp Sci & Visual Arts	|	-The BOOK, Hitchhikers guide to the galaxy.  |
------------------------------------------------------------------------------

In message <RJM.96Feb8133827@swift.eng.ox.ac.uk>
(08 Feb 1996 13:38:27 GMT), Bob Manners typed:

> Wouldn't be the first time I was wrong! I thought the Speccy could
> read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
> unlikely for Sinclair to do this though ...

No, the Spectrum couldn't read ZX81 tapes.

I remember typing in a listing from a magazine once (Your Computer,
I think) that was supposed to allow it to do this; but I couldn't
get it to work.

-- 
Richard
-=-=-=-
Richard G. Hallas          -oOo-          Editor of RISC User magazine
Proprietor of KeyNote:  Music Typesetting & General Desktop Publishing
E-mail: Richard@hallas.demon.co.uk * Telephone/Facsimile: 01484 460280

R Ribeiro (rff-ribe@csm.uwe.ac.uk) wrote:
: Hello:

: 	I think that you're right till a certain point. It will work indeed,
: but is like a deck copy (a copy from tape to tape): with each copy you're
: increasing the level of noise...it will be better if it was decoded and
: saved afresh!

: 	I have done in a PC a routine that reads Spectrum tapes and creates
: a .TAP file in a disk (a binary image of the contents of the tape, already
: translated). Apart for the little space it uses (compared to .WAV), I

That sounds ideal, but will it read speed loaders?


I think whats really needed is a complete rethink because at the moment it's not
possible to play multiloads that used different routines to the rom one, on any
emulator that I know of unless you use the actual tape or an image of it stored
as a sound file of some sort. What we need is something like a mixture of the
two, ways of doing it. a .tap format but with a varied baud rate, and an option
in an emulator to 'play' the .tap in like a .wav file so the m/c program is
fooled in to thinking its getting real sound data, having to use an option would
be like pressing play on the cassette recorder so I don't think thats a bad
thing. This would involve a rewrite of most emulators unfortunatly. It 'might'
be better just to hack the games so that they receive normal data using the rom
and so the emulator can fake this in the normal way.

: think it's easier to manipulate. (at least for my emulation -- still in a 
: early state).

: 	It has it's only problems, but I am considering to put it as GNU or
: something like that... to see if other people are interessed in picking were
: I left.

: 	It reads from printer port and from a SoundBlaster: but it's still
: some problems with noisy tapes.

: 		Bye,
: 		Rui Ribeiro


--
Damion Yates - Sheffield Uni, UK.
http://www.bath.ac.uk/~exxdmy

In article <4fcvsn$r4d@news.ox.ac.uk>,
John Elliott <elliott@teaching.physics.ox.ac.uk> wrote:
>In article <RJM.96Feb8133827@swift.eng.ox.ac.uk>, Bob Manners (rjm@swift.eng.ox.ac.uk) wrote:

>: Wouldn't be the first time I was wrong! I thought the Speccy could
>: read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
>: unlikely for Sinclair to do this though ...

>  It _can_ read ZX81 tapes; since the processors run at the same speed and the
>hardware's very similar, you just copy the relevant ZX81 ROM code into the 
>Spectrum and away you go. This only loads the program as a raw memory dump,
>but you get the data. I've written a program to do this, which works fine on
>my real Spectrum, but no-one seems able to get it to work on an emulator.

It hadn't even occurred to me to just plug in a ZX81 tape and load it in
with the ZX81's tape code.  What a great idea!

I've got a commercial program for the TS2068 (it hasn't been sold for 
several years) that reads in ZX81 programs and does token conversion so 
that you can run the BASIC program on the 2068.  They give instructions 
for inserting a capacitor and resistor in the tape lead (some kind of 
filter).  I tried to load ZX81 programs without it, but couldn't.  Maybe 
there's a subtle difference between the Spectrum and TS2068 tape 
interface?  I've never had trouble loading commercial Spectrum software 
by tape.

Alvin

 
In article <RJM.96Feb7174404@swift.eng.ox.ac.uk>, Bob Manners (rjm@swift.eng.ox.ac.uk) writes:
>
>>   ????       Vic-20 (may not be readable on standard casstte recorder)
>>   ????       C-64   (may not be readable on standard casstte recorder)
>
>Should be readable. There was a kit I remember from a few years ago to
>use a `normal' cassette machine with the VIC/C64. The only difference
>with the Commodore version was a fixed record/replay level. I can find
>out the VIC/C64 pinout for the cassette port if you like.
>
>>   ????       Atari 8-bit systems
>
>These also used a proprietry records, but I imagine that what I said
>for Commodore also applies here.
>
>>   ????       IBM-PC
>
>Not much point? How much was available on tape?
>
>>   ????       Sinclair (various models, do they all use the same format?)
>
>I think the ZX80/81/Spectrum used the same encoding.

        The ZX80 and ZX81 were compatible with each other, but only
the ZX81 was compatible with the Speccy (At least in my
experiance.) most strange !!


Cheers !

Chip Pieroni..
 

---
Chip Pieroni

Vintage Systems Finder

        The program BASICA can use tape on certain machines. (Those
fitted with a relay..)


Cheers !

Chip Pieroni.. 

---
Chip Pieroni

Vintage Systems Finder

In article <19960209.005116.65@hallas.demon.co.uk>
           Richard@hallas.demon.co.uk "Richard G. Hallas" writes:

> 
> In message <RJM.96Feb8133827@swift.eng.ox.ac.uk>
> (08 Feb 1996 13:38:27 GMT), Bob Manners typed:
> 
> > Wouldn't be the first time I was wrong! I thought the Speccy could
> > read ZX81 tapes? Maybe it has a backwards compatibility mode? Seems
> > unlikely for Sinclair to do this though ...
> 
> No, the Spectrum couldn't read ZX81 tapes.
> 
> I remember typing in a listing from a magazine once (Your Computer,
> I think) that was supposed to allow it to do this; but I couldn't
> get it to work.
> 
> -- 
> Richard
> -=-=-=-
With ZX Slowloader issue 2 Spectrums could load ZX81 tapes and
they were converted to Spectrum basic.

Brian

-- 
briang@bgserv.demon.co.uk
Brian Gaff AKA B G Services - Still supporting Z80
                              The Spectrum Emulator