swillden@wsccs.UUCP (Shawn Willden) (10/14/88)
I need an interface for a cassette tape for an atari 800XL. I don't know if I need just an interface or an atari tape recorder too. I might be interested in getting a disk drive instead, if the price is low enough. I can probably build my own interface to a tape drive if it is not too incredibly complicated and if someone can tell me where to get a 13-pin male connector. Could someone please point me in the right direction, or at least tell me what I need? If you're considering junking your old atari or have an extra interface lying around somewhere, I would be willing to pay for it. e-mail your responses to me. swillden@wsccs
cfchiesa@bsu-cs.UUCP (Christopher Chiesa) (10/20/88)
In article <736@wsccs.UUCP>, swillden@wsccs.UUCP (Shawn Willden) writes: > I need an interface for a cassette tape for an atari 800XL. I don't > know if I need just an interface or an atari tape recorder too. I might > be interested in getting a disk drive instead, if the price is low > enough. I can probably build my own interface to a tape drive if it > is not too incredibly complicated and if someone can tell me where to > get a 13-pin male connector. 1) You don't need an 'interface' if you obtain an Atari cassette drive - they are made to plug right into the SIO port, although they have only ONE SIO connector and therefore "terminate" any daisy chain. (This implies that you can't have the cassette unit and any OTHER terminating peripheral (the SX212 modem in SIO-direct mode, for example) connected at the same time.) There are two units in existence that I know of, the 410 and (someone cor- rect me if I'm wrong) the 1010. The 410 is of the 400/800 generation, and the 1010 is of the XL generation, but EITHER should work with ANY 8-bit Atari. I personally have a 410 that I rarely use, but have just recently thought of an interesting use for cassette storage, so am loath to sell... sorry. 2) Disk drives are infinitely better: faster, random-access, more space. I HAVE heard, however, from a friend who got the new XM551 drive and does NOT like it... (Ooh, I can feel the flames already... ask 'aegnor@bsu-cs' about Mike W's experience; 'aegnor' is the one who was telling ME.) 3) I don't imagine the interface to a standard tape recorder should be too complicated; data is stored and retreived as audio tones on, I believe, the LEFT channel of a standard stereo recording, with capability to play right-channel audio through the TV/monitor speaker! You should be able to simply connect the audio inputs, outputs, and ground, to the appropriate SIO pins, as well as using some kind of control circuit (I do NOT recommend direct connection here) to turn the cassette player's MOTOR on and off in response to the appropriate SIO signals. (On the other hand, you could probably get away with leaving it ALWAYS on, in some if not all cases. There ARE cases where the computer NEEDS to start and stop the tape, however.) 4) Alas, I don't know where to get an SIO plug, but there must be SOMEPLACE since there is a continuing flow of SIO cables etc. Scavenge a cable if you have to. Probably the easiest way of obtaining one, when you get right down to it. Hope this is helpful; good luck! If you DO hack together an interface to a standard cassette recorder, let me know; I have a reel-to-reel I'd like to try using... Chris Chiesa almost gone from Ball State University -- UUCP: <backbones>!{iuvax,pur-ee,uunet}!bsu-cs!cfchiesa cfchiesa@bsu-cs.UUCP
gdtltr@vax1.acs.udel.EDU (Gary D Duzan) (10/20/88)
In article <4408@bsu-cs.UUCP> cfchiesa@bsu-cs.UUCP (Christopher Chiesa) writes: >In article <736@wsccs.UUCP>, swillden@wsccs.UUCP (Shawn Willden) writes: >> I need an interface for a cassette tape for an atari 800XL. I don't >> know if I need just an interface or an atari tape recorder too. I might >> be interested in getting a disk drive instead, if the price is low >> enough. I can probably build my own interface to a tape drive if it >> is not too incredibly complicated and if someone can tell me where to >> get a 13-pin male connector. > >2) Disk drives are infinitely better: faster, random-access, more space. I > HAVE heard, however, from a friend who got the new XM551 drive and does NOT > like it... (Ooh, I can feel the flames already... ask 'aegnor@bsu-cs' > about Mike W's experience; 'aegnor' is the one who was telling ME.) > Agreed about drives. I think tape recorders hate me (I, naturally enough, reciprocate). There are a couple problems with the XF551, but nothing that can't be overcome with a little hacking. >3) I don't imagine the interface to a standard tape recorder should be too > complicated; data is stored and retreived as audio tones on, I believe, > the LEFT channel of a standard stereo recording, with capability to play > right-channel audio through the TV/monitor speaker! You should be able > to simply connect the audio inputs, outputs, and ground, to the appropriate > SIO pins, as well as using some kind of control circuit (I do NOT recommend > direct connection here) to turn the cassette player's MOTOR on and off in > response to the appropriate SIO signals. (On the other hand, you could > probably get away with leaving it ALWAYS on, in some if not all cases. There > ARE cases where the computer NEEDS to start and stop the tape, however.) > I think you will find it more complicated than you think. Remember that all I/O devices attached to the SIO port MUST BE INTELLIGENT!!! I believe the 1050 drive has a microprocessor almost as powerful as the 6502 (not a great statement, but it is better than nothing). An SIO call sends data to the processor on the device and the device responds with the proper data, not just some sounds. There is a pin on the SIO to allow an audio signal to pass though the computer and out through your monitor speaker and a motor on/off pin, so you could probably get it to play, but reading data off it is out of the question without a processor chip. >4) Alas, I don't know where to get an SIO plug, but there must be SOMEPLACE > since there is a continuing flow of SIO cables etc. Scavenge a cable if > you have to. Probably the easiest way of obtaining one, when you get > right down to it. > If necessary, you could probably tap lines in an existing cable. I know a couple people who built a voice synthesizer called Cheap Talk (it fits in a cassette tape box). The synthesizer was controlled through one of the joystick ports, but instead of hooking the output to an external speaker, he stole the audio in line from an existing SIO cable and send the output there, routing the sound through his monitor. If you want to look at the pinouts of the SIO interface, they are in Mapping the Atari XL/XE version p.198. Gary Duzan Time Lord Third Regeneration Atari Enthusiast Extreme
cfchiesa@bsu-cs.UUCP (Christopher Chiesa) (10/21/88)
In article <2170@udccvax1.acs.udel.EDU>, gdtltr@vax1.acs.udel.EDU (Gary D Duzan) writes: > In article <4408@bsu-cs.UUCP> cfchiesa@bsu-cs.UUCP (Christopher Chiesa) writes: [disk preferences over cassette, deleted...] > >3) I don't imagine the interface to a standard tape recorder should be too > > complicated; data is stored and retreived as audio tones on, I believe, > > the LEFT channel of a standard stereo recording, with capability to play > > right-channel audio through the TV/monitor speaker! You should be able > > to simply connect the audio inputs, outputs, and ground, to the appropriate > > SIO pins, as well as using some kind of control circuit (I do NOT recommend > > direct connection here) to turn the cassette player's MOTOR on and off in > > response to the appropriate SIO signals. (On the other hand, you could > > probably get away with leaving it ALWAYS on, in some if not all cases. There > > ARE cases where the computer NEEDS to start and stop the tape, however.) > > > I think you will find it more complicated than you think. Remember that all > I/O devices attached to the SIO port MUST BE INTELLIGENT!!! I believe the > 1050 drive has a microprocessor almost as powerful as the 6502 (not a great > statement, but it is better than nothing). Alas, I have a bone to pick with you on this information, Gary. Are you sure you're not confusing the CASSETTE drive (and interface) with a DISK drive and interface? I don't quite see the connection between the original question of creating a cassette interface, and the microprocessor in the 1050 disk drive. The original posting had nothing to do with the 1050 or any other DISK drive; the poor fellow simply stated that he wanted to build an interface for CASSETTE. Normally, you would be quite correct in stating that such a project would be complex because the resulting SIO device "MUST BE INTELLIGENT" -- but in the case of the cassette drive and interface, that is NOT so. To wit: OS Listing, page 42 (line 1736, within the SIO Controller code): "All devices EXCEPT CASSETTE are inteligent." OS User's Manual, section 3, under "Program Recorder": "The ATARTI 410 [TM] Program Recorder is a special peripheral. It uses the serial bus to send and receive data, but does not conform to the protocol of the other peripherals that use the serial bus." That pretty well defeats the argument that the interface is complex in terms of its requiring INTELLIGENCE; however, you may still have a point, which I implicitly conceded in my first posting, that the data MAY or MAY NOT be transmitted back and forth as audio tones. > An SIO call sends data to the > processor on the device and the device responds with the proper data, not just > some sounds. I'm sure this is true, in most cases, but the CASSETTE as noted is treated differently. Section 11 of the OS User's Manual, under "SOUND GENERATION," refers obliquely to "... cassette FSK tone generation," and chapter II, section C, page II.26 (my God, I sound like a lawyer; forgive me!) of the Hardware Manual states that "Output data is normally transmitted as logic levels (+4V=true 0V=false). Data can also be transmitted as two tone information. ... In this mode audio channel 1 is transmitted in place of logic true, and audio channel 2 in place of logic zero." Taken together, it sure SOUNDS (no pun intended) as though the cassette WRITE operation, at least, is performed in two-tone mode. Unfortunately, there is no corresponding informaition implying or stating ANYTHING about cassette READ operations. > There is a pin on the SIO to allow an audio signal to pass though > the computer and out through your monitor speaker and a motor on/off pin, so > you could probably get it to play, but reading data off it is out of the > question without a processor chip. Au contraire; it seems rather likely that he could get it to RECORD data, and that PLAYING BACK data is at worst still "up in the air." I'd say he still has a shot at it. And if he succeeds and tells us how he did it, ya know what I'm gonna do? I'm gonna develop some really cool software here at home, at leisure, then save it to cassette as a casette-bootable binary, make a special adapter for my Walkman to connect to the Atari SIO port, take the whole shootin' match to the local department store's Atari XEGS display area, and quickly upload a sharp-looking showoff demo! They won't know where the heck it came from, unless I specifically tell 'em. Hehehe. Chris Chiesa -- UUCP: <backbones>!{iuvax,pur-ee,uunet}!bsu-cs!cfchiesa cfchiesa@bsu-cs.UUCP
ken@hpclkms.HP.COM (Kenneth Sumrall) (10/21/88)
/ hpclkms:comp.sys.atari.8bit / gdtltr@vax1.acs.udel.EDU (Gary D Duzan) / 7:49 pm Oct 19, 1988 / >> >>3) I don't imagine the interface to a standard tape recorder should be too >> complicated; data is stored and retreived as audio tones on, I believe, >> the LEFT channel of a standard stereo recording, with capability to play >> right-channel audio through the TV/monitor speaker! You should be able >> to simply connect the audio inputs, outputs, and ground, to the appropriate >> SIO pins, as well as using some kind of control circuit (I do NOT recommend >> direct connection here) to turn the cassette player's MOTOR on and off in >> response to the appropriate SIO signals. (On the other hand, you could >> probably get away with leaving it ALWAYS on, in some if not all cases. There >> ARE cases where the computer NEEDS to start and stop the tape, however.) >> >> I think you will find it more complicated than you think. Remember that all >I/O devices attached to the SIO port MUST BE INTELLIGENT!!! I believe the >1050 drive has a microprocessor almost as powerful as the 6502 (not a great >statement, but it is better than nothing). An SIO call sends data to the >processor on the device and the device responds with the proper data, not just >some sounds. There is a pin on the SIO to allow an audio signal to pass though >the computer and out through your monitor speaker and a motor on/off pin, so >you could probably get it to play, but reading data off it is out of the >question without a processor chip. > You can make an interface to connect a standard tape recorder to the Atari. However, you must first build a little circuit. The reason is that the Atari uses FSK modulation of the signal when it stores it on the tape, and you must add this FSK circuitry between the Atari and a standard tape recorder. Someone designed such a circuit and published it in the now defunct magazine Popular Electronics. I don't remember when it was published, but it was at least three years ago. If you can't find it, I will go through my back issues and find the issue for you. Also, even though the SIO bus is intelligent, and the 1050 disk drive has a 6507 CPU, (which is a limited addressing, limited interrupts version of the 6502), the tape recorder is a dumb device. It uses the motor start stop to control the tape deck, and has no feedback as to whether the data was written properly. The ONLY time I ever use my tape recorder is when I get old software on tape, and I want to move it to disk. I then junk the tape, and put the tape drive back in the closet. (I used to play Pink Floyd tapes through the TV speaker before I had a stereo in the same room as the Atari, but that was 8+ years ago.) Hope this helps. Kenneth Sumrall ken%hpclkms@hplabs.hp.com ...!hplabs!hpclkms!ken
kimes@ihlpe.ATT.COM (Kit Kimes) (10/21/88)
> [much deleted info] > > Au contraire; it seems rather likely that he could get it to RECORD data, and > that PLAYING BACK data is at worst still "up in the air." I'd say he still > has a shot at it. > I have kept out of this discussion basicly because I am lazy. I know I have a circuit somewhere that shows how to make just such an interface. Lazy is one reason but unnecessary in another reason. I have seen NEW Atari cassette devices for about $25 and I'm sure you could pick up an used one for a lot less. However, one company used to sell such an interface for about $40 (which is way too high even if you could find one) to use with a regular tape recorder/player. I say don't bother, but a used Atari. > > And if he succeeds and tells us how he did it, ya know what I'm gonna do? I'm > gonna develop some really cool software here at home, at leisure, then save > it to cassette as a casette-bootable binary, make a special adapter for my > Walkman to connect to the Atari SIO port, take the whole shootin' match to > the local department store's Atari XEGS display area, and quickly upload a > sharp-looking showoff demo! They won't know where the heck it came from, > unless I specifically tell 'em. Hehehe. > This is the first practical use I have heard for the above mentioned interface. A real stroke of genius! Good luck Chris. Kit Kimes AT&T--Bell Laboratories ...att!ihlpe!kimes
hans@umd5.umd.edu (Hans Breitenlohner) (10/22/88)
There have been some confusing ideas thrown about lately regarding cassette interfaces, so I would like to clear some of this up. (Of course, I don't know why anybody should believe my version over anybody else's!) Atari cassette recorders are dumb. I have seen the inside of one myself, and there is almost nothing in them. Also I understand that the 1010 is no better than the 810, just repackaged. Data is recorded serially (obviously), I believe at 600 baud. For recording the computer generates the tones (for two tone, of FSK recording mode), and the cassette drive simply records the audio signal. For playback the cassette drive converts the tone to a logic level, which is fed back to the computer. The circuit is primitive, nothing so fancy as a PLL. But you do need stuff beyond what a tape recorder will give you. The early issues of Antic had a column just on stuff such as this. I would encourage to try to find some, they make interesting reading.
BobR@cup.portal.com (Bob BobR Retelle) (10/22/88)
Just to add to the discussion of how the cassette drive (C:) works on the 8-bit Atari... As Chris Chiesa indicated, the cassette device is a "special case", and does not operate as a normal SIO device. The POKEY chip translates the logic data into "two tone" audio (much like a modem does), then sends it to the cassette, which records it as regular audio. Reading data is the re
BobR@cup.portal.com (Bob BobR Retelle) (10/22/88)
Oops... sorry about that... "macro fingers" hit "done" rather than "edit"..! Just to add to the discussion of how the cassette drive (C:) works on the 8-bit Atari... As Chris Chiesa indicated, the cassette device is a "special case", and does not operate as a normal SIO device. The POKEY chip translates the logic data into "two tone" audio (much like a modem does), then sends it to the cassette, which records it as regular audio. Reading data is the reverse process, with the audio "two tone" signal being translated back into logic data. Addressing the C: device with a LOAD "C:" or SAVE "C:" is what puts this method into action. A normal audio cassette recorder *will* work, but not very well. The problem is that most audio recorders have too *good* a frequency response, and are designed to work with sine waves... the Atari data recorder has circuitry to clip the audio, square it off, and restrict the frequency response to the narrow range of tones coming from the computer. Thus, using a Walkman *may* work, but not as well as a 410/1010... I used to sell Atari software and experimented for a time with multiple recorder set-ups to do mass duplication, and the results were never very satisfactory with audio recorders... (but what the heck... give it a try..!) In answer to the original request for information about obtaining an Atari cassette recorder, there is a company called B&C ComputerVisions which advertises in the Atari magazines, I see their ad in the November '88 ANTIC magazine. They used to list the cassette drive very cheaply, and may still have them. Other ads in the magazines may be worth calling too... BobR
charles@c3sw.uucp (Charles Green) (11/02/88)
In article <4408@bsu-cs.UUCP> cfchiesa@bsu-cs.UUCP (Christopher Chiesa) writes: >1) You don't need an 'interface' if you obtain an Atari cassette drive - they > are made to plug right into the SIO port, although they have only ONE SIO > connector and therefore "terminate" any daisy chain. (This implies that The Atari 1010 program recorder (I have one) has two SIO connectors. > I HAVE heard, however, from a friend who got the new XM551 drive and does NOT > like it... I have the Atari 1050 disk drive, and DO like it, although I wish it did "true" double density, with twice the data storage of single-density, rather than half again. And imagine what 512-byte sector support could do for program interchange: "Sure, I can read that PC-DOS diskette!" (Happy Computers Inc, are you listening?). > about Mike W's experience; 'aegnor' is the one who was telling ME.) > complicated; data is stored and retreived as audio tones on, I believe, > the LEFT channel of a standard stereo recording, with capability to play > right-channel audio through the TV/monitor speaker! You should be able > to simply connect the audio inputs, outputs, and ground, to the appropriate > SIO pins, as well as using some kind of control circuit (I do NOT recommend As already pointed out, the Atari uses the Pokey two-tone mode to output FSK on the serial output pin. (This FSK is, alas, apparently not phase-coherent, which may be why we are limited to 600 bauds.) Thus, you can *record* Atari tapes, with no further electronics, on a standard cassette deck. To read them back, however, you must present the decoded data to the serial input pin. That requires an FSK demodulator, the only "magic" in the Atari program recorder. Before I bought my Atari 1010, I bought an Exar XR2211 FSK Demodulator chip, and got excellent results writing and reading tapes. In fact, the 1010 gave much *worse* performance than my simple one-chip solution! One of these days, I'll do some serious experimenting with some custom tape I/O software and the XR2206 (phase-coherent) FSK modulator. If a Bell 103 can do 300 baud in 1.5kHz bandwidth, 12kHz on a tape deck would give 4800bps and using all four tracks in a stereo deck will yield 5 Megabytes on a C-90. -- Charles Green charles@c3pe.UUCP {decuac,cucstud}!c3pe!charles
slackey@bbn.com (Stan Lackey) (11/02/88)
>In article <4408@bsu-cs.UUCP> cfchiesa@bsu-cs.UUCP (Christopher Chiesa) writes: >One of these days, I'll do some serious experimenting with some custom tape >I/O software and the XR2206 (phase-coherent) FSK modulator. If a Bell 103 In my pre-atari, pre-sinclair days, I was fooling around with a home-built 6800-based system. I built a simple mod-demod with a 555 (voltage controlled osc) and 556(?) phase locked loop. I connected a UART to the 6800, and connected the serial I/O from the UART into my widget. I used freq's like 3000Hz for a 1 and 3300 for a 0 or so. It worked totally reliably at 1200 baud! I guess I should have tried it at higher baud rates... I had fun anyway. -Stan
cfchiesa@bsu-cs.UUCP (Christopher Chiesa) (11/03/88)
In article <31750@bbn.COM>, slackey@bbn.com (Stan Lackey) writes: > >In article <4408@bsu-cs.UUCP> cfchiesa@bsu-cs.UUCP (Christopher Chiesa) writes: > >One of these days, I'll do some serious experimenting with some custom tape > >I/O software and the XR2206 (phase-coherent) FSK modulator. If a Bell 103 > No, I DIDN'T write that. That was written by the person who quoted part of my earlier posting. Chris -- UUCP: <backbones>!{iuvax,pur-ee,uunet}!bsu-cs!cfchiesa cfchiesa@bsu-cs.UUCP