PDA

View Full Version : RCP/M, PMMI Modem, and Altair modem program



virtualaltair
July 5th, 2010, 08:33 AM
I'm trying to transfer a program to an Altair hard-sectored CP/M system. The system has modem7 and a PMMI S-100 Modem. The system does not have a file transfer program for a direct connection to an Altair/Motorola 6850 serial port.

Are there RCP/M systems still on the telephone network?

Does anyone have an auto-answer system that can negotiate a 300-600 Baud telephone connection and xmodem file transfer with a PMMI modem?

Does anyone have a modem/xmodem program configured for Altair/Motorola 6850 I/O?

Tom Sanderson

Chuck(G)
July 5th, 2010, 09:39 AM
Does your Altair have BIOS support for the serial port? If so, you can bootstrap your way to serial transfer using PIP.

You might also look through the overlays for Chuck Forsberg's IMP to see if there's a 6850-based one there.

MikeS
July 5th, 2010, 11:51 AM
Does your Altair have BIOS support for the serial port? If so, you can bootstrap your way to serial transfer using PIP.

You might also look through the overlays for Chuck Forsberg's IMP to see if there's a 6850-based one there.Failing that, if all you need is a system that'll answer at 300 or 600 and let you D/L a file with xmodem, that sounds easily doable unless that PMMI modem card has some non-standard quirk(s)?

Send me the file and arrange a time if you want to try it.

virtualaltair
July 5th, 2010, 06:28 PM
Does your Altair have BIOS support for the serial port? If so, you can bootstrap your way to serial transfer using PIP.

You might also look through the overlays for Chuck Forsberg's IMP to see if there's a 6850-based one there.

I tried PIP and could not find support for a serial port. Thanks for the pointer to IMP.

Tom

virtualaltair
July 5th, 2010, 07:15 PM
Thanks Mike,

I have MDM 7.12 configured for a Vector Graphic Bitstreamer. I have a Bitstreamer in an Altair. If I can get MDM 7.12 to the Altair, I can use it to move a M6850 version when I find one.

My CP/M boot disk has modem and modem 7 configured for a PMMI. The Altair can pulse dial through my Vonage adaptor and I need a compatible system to call for a file transfer. I do not know for sure if the modem transfer process works with VoIP.

I don't remember if Modem7 defaults to 300 or 600 Baud. I don't believe modem 7 has a baud rate change command. From what I understand both 300 and 600 Baud are "standard" and within the limits of the "standard" phone system.

The quirk is that the standard evolved for newer faster modems. The auto-negotiation for speed is not supported by the PMMI. From what I read, the auto-answer system must be set to expect the PMMI Baud rate.

Does this still sound doable?

My task of building a better hard-sectored Altair CP/M boot disk has given me a list of questions:

How many people have Altairs with working drives?
How many Altair owners use CP/M?
How many S-100 owners use modems and the phone system?
Are their any public RCP/M systems in 2010?
Does anyone still use the PMMI?
Will the old hardware and software work with VoIP
Will the old hardware and software work with a cell phone and Bluetooth gateway?


Tom

Chuck(G)
July 5th, 2010, 07:55 PM
Do you have another modem capable of 300 bps? You can wire them back-to-back if you can ignore the lack of dial tone and ring and set one to use reverse frequencies (most Hayes-compatible modems can do this).

I have no experience with the PMMI. When I had my S100 system (I've got an Altair, but moved up to an Integrand when I installed disks), I used a Racal Vadic 3451 modem with the MITS SIO1 card.

MikeS
July 5th, 2010, 08:09 PM
Do you have another modem capable of 300 bps? You can wire them back-to-back if you can ignore the lack of dial tone and ring and set one to use reverse frequencies (most Hayes-compatible modems can do this).Yeah, trivial with Hayes-compatible modems, but not so easy with the old "dumb" modems...


I have no experience with the PMMI. When I had my S100 system (I've got an Altair, but moved up to an Integrand when I installed disks), I used a Racal Vadic 3451 modem with the MITS SIO1 card.Same here, no experience with the PMMI or any non-RS-232 modems for that matter, but I haven't had any problems connecting to a Hayes-compatible with a dumb 300 bd modem (such as in my R-S M100 for example).

MikeS
July 5th, 2010, 08:34 PM
Hi Tom:

I think I've seen you on the Vector Graphic mail list? Not that it's relevant, but I've got a couple of VG boxes, also with Bitstreamers and the RS-232 monitor ROM that includes a primitive 300bd comm function IIRC.

Off-hand I don't see why you couldn't connect to a 'normal' modem/terminal program at 300bd and transfer files with xmodem; VoIP might cause problems, but 300 bd is pretty tolerant.

Worth a try; if you want, PM me and I'll send you a phone number and get one of my systems ready to answer. If you've got a comm program that you want to download, send it to me in an email and I'll put that up for you, assuming the connection works.

Don't have any answers to your questions; there are a few Altair owners on here that might have some info. There's occasionally been talk about putting up an RCP/M system but I don't know whether there actually is one on line anywhere; most BBSs are accessed over the Internet these days using an RS-232<>Telnet bridge of some kind, either a dedicated unit like the Lantronix:
http://www.lantronix.com/device-networking/external-device-servers/uds-10.html
or bridge software running on your Internet-connected computer like TCPSER for example. Either way your classic box thinks it's talking to a Hayes-compatible modem.

AFAIK VoIP doesn't do data very well, but at 300 bd you might be OK; another issue with Bluetooth etc. is that data is sent in packets, which can cause issues with protocols like xmodem etc. because of the latency. Again, others on here like James in Australia have more experience with these issues than I do; maybe one of them will chime in.

mike

virtualaltair
July 6th, 2010, 06:56 AM
Mike,

I am on the Vector Graphic list. Here is my VG collection: http://vector-graphic.info/. VG is relevant to me, because I use my VG equipment to support my Altairs. My Altair Attache (http://tom12.tech.officelive.com/attache.aspx) contains a mostly VG board set. I'm setting up a direct connection to my Altair (http://tom12.tech.officelive.com/8800bSN300000104.aspx).

The PMMI (http://tom12.tech.officelive.com/PMMI.aspx) was my first S-100 board and I still love it. The Tarbell 1011D (http://tom12.tech.officelive.com/Tarbell1011D.aspx) was my second S-100 board. My interest was RCP/M and modem communication. I set up an RCP/M and all my CP/M source code is on 8-inch SSSD diskettes.

My goal is to get all my source code to the internet. I want to set up an Altair RCP/M and VG RCP/M and document the configuration. The evolution of the phone system may limit the use of the old technology, but learning the limits are part of the fun. I can still get a land line, but will there be anyone left to call my RCP/M.? I'm building multiple Altairs (http://tom12.tech.officelive.com/) so at least they can network with each other.

My Altair console is on the internet using a serial server (http://tom12.tech.officelive.com/GW312.aspx). I may follow the trend and set up BYE on the internet. That is the server side. Where do I get a CP/M Telnet client? Testing file transfer over the net will be more fun. I can connect two S-100 systems to the net. To what extent can I use CP/M software? I can set up phone modems. To what extent can I use the modern phone system? Do I need an iModem protocol?

Mike, I'll contact you to exchange phone numbers and send the program MDM712B6. The program is MDM 7.12 configured for port B of a Bitstreamer. The 8251A/9551 initialization works at 6MHz. The program should work on your VG boxes.

Chuck, a direct connect should work with dump rubber cup modems, but the PMMI software will wait for a dial tone or ring.

Tom

glitch
July 6th, 2010, 08:17 AM
The Grex system still supports XMODEM transfers. I know their dialins will accept calls as low as 1200 baud, but I don't have a slower modem to try with. You can dial them at (734) 484-0512 -- if the connection works, read through the information on creating a new account at http://www.grex.org . I use my account with them to transfer files from my various computers over ftp or sftp and then pull them down using Kermit or XMODEM.

virtualaltair
July 6th, 2010, 09:55 AM
The Grex system still supports XMODEM transfers. I know their dialins will accept calls as low as 1200 baud, but I don't have a slower modem to try with. You can dial them at (734) 484-0512 -- if the connection works, read through the information on creating a new account at http://www.grex.org . I use my account with them to transfer files from my various computers over ftp or sftp and then pull them down using Kermit or XMODEM.

Thanks, I tried the connection and received the following message from Modem 7:

Connection established - Select options:

That indicates that the modems were communication and ready to negotiate bit rate. I selected T for Terminal mode and pressed Enter a few times. HyperTerminal displayed }{}}}}{}}{}}}{} . That indicates that bit rate negotation was not successful.

This is an example of the problem as I understand it. The 14.4k modem at Grex answers the phone and tries to negotiate with a smart modem. The PMMI is not smart enough to negotiate with modems faster than 1200 BPS. I think only old 1200 BPS modems might work.

Here is a quote from from Rich Cini in Thread: Bulletin board and Modem question (http://www.vintage-computer.com/vcforum/showthread.php?14712-Bulletin-board-and-Modem-question)

"The only comment I'll make with regards to modems is that the auto-negotiation feature of the new modems (even 1200 baud modems) messes up the PMMI (and probably other 300-only baud modems). I found that I could only successfully connect to the 300-baud host if I forced the 1200-baud modem to work at 300-baud (on Windows, use a 300 baud port speed)."

This makes the connection sound possible, but only if the host is expecting my call or uses a PMMI. When I get BYE running, Smart modems can call me if they set their terminal program to 600/450/300/110 baud. I'm using the PMMI because I like it and it already is on MITS format diskette. I'll upload smart modem software after I get a direct 9600 Baud connection set up.

Tom

virtualaltair
July 12th, 2010, 02:36 PM
I have a Remote CP/M running using a PMMI modem, Vector Graphic board set, and 54K Vector Graphic CP/M.

Does anyone have a modem, phone line, and time to call my system to test a file transfer over Vonage VoIP? If so, please send me a private message to get the phone number and arrange a test.

Tom

Dr_Acula
July 23rd, 2010, 01:53 AM
Sorry to chime in a bit late on this thread - I've been on holidays.

Re "I tried PIP and could not find support for a serial port. Thanks for the pointer to IMP. "

Getting PIP to work is a bit tricky. CP/M may well have already mapped the serial port(s) to internal CP/M devices such as Reader and List. I did some quick research on the Altair and it depends on which computer you have, but I see some have DIP switches for the serial ports.

A lot of my work uses the Altair SIMH so I'm familiar with the port settings for that and it may be they are similar - eg between 10H and 20H.

I'm working on packet software at the moment using MP/M as a router, but one of the parts of this project is to interface to a machine that has virtually nothing on it. Build it up with PIP as Chuck says, pip over xmodem, recompile xmodem for the machine's port settings etc. You need some background information for that.

As a testbed I'll be starting with a CP/M board with PIP and maybe Mbasic and not much else. It is a bit of an intellectual challenge to try to build it up from there, with ideally the smarts on the controlling machine.

At the very minimum I'm thinking maybe Mbasic and OUT and IN commands, or PIP using existing devices and let CP/M do the work.

I don't think the first program you PIP is xmodem though, as xmodem needs port settings to be known, and they will be different for every machine. I think the first program to PIP over is some sort of sniffer program that tests all serial ports and then the MPM board uses that information to build a custom version of xmodem, compiles it and sends it over. Then use xmodem to send over a terminal program that can talk to the packet network.

What does the hardware look like on the back - is there a serial port anywhere?

And what sort of software do you have? Any chance of Mbasic - if so then you could write a little program to send a byte to ports 0 to 255. On an Altair, I'd hope for some action from port 10H up.

Alternatively, DDT may be useful to get the bios jump at 0005H and see where it goes and see where the ports are for the bdos calls for the reader and list devices. Do you have DDT?

virtualaltair
July 26th, 2010, 09:56 AM
Hello Dr_Acula,

I was hoping to hear from you. It's not too late. Several people similar interests, but work in different years. I'm documenting what I find in web pages for the person next year.

My test bed is very different. I'm not starting with a bare system. I'm upgrading what I have and will work my way backwards to early Altairs, non-MITs drives, and no hardware drives. I've quit using the PMMI modem (http://tom12.tech.officelive.com/PMMI.aspx) for now and also waiting to implement "AT" command set modems. I'm doing parallel development using the Altair 88-2SIO (http://tom12.tech.officelive.com/882SIO.aspx) and Vector Graphic Bitstreamer II (http://tom12.tech.officelive.com/BitstreamerII.aspx). For now, I am ignoring the Altair 88-SIOA (http://tom12.tech.officelive.com/Altair88SIOA.aspx) and non-MITS boards (http://tom12.tech.officelive.com/SolidStateMusicIO4.aspx) often used by early Altairs.

I've made a lot of progress. I have the BSTAM communications software on both VG and MITS hard-sectored format. I have a Bitstreamer and MITS 88-2SIO boards in a VG configuration system (http://tom12.tech.officelive.com/attache.aspx) and a MITS 300/25 (http://www.virtualaltair.com/virtualaltair.com/vac_altair_mits_300_25.asp) configuration. I used BSTAM to transfer BYE, MEX, Modem7, Kermit, Sweep, and Wash to Altair format. PIP is out of the picture for now. I can also Squeeze/Unsqueeze files and use LBR libraries.

I have a PMMI BYE working for 54K VG and 60K MITS CP/M 2.2. I want to upgrade my RCP/M to a newer version, eliminate modems, and use an RS-232 connection to an Ethernet serial server. I'm updating utilities too.

The goal is a common set of tools with source code for 8251A/9551 IO, M6850 IP, standard MITS and VG addresses, VG CP/M, MITS Burcon CP/M, and Tarbell SSSD CP/M. I want a RCP/M a file transfer without Telnet. I'm using a GW312 serial to Ethernet server (http://tom12.tech.officelive.com/GW312.aspx). Is anyone else using a serial to Ethernet device compatible with Tactical Software virtual COM drivers?

I have a sub-domain that address my router and the firewall routes serial server traffic to two RS-232 ports. I can do console operation and file transfer without Telnet. Now I want to configure BYE and Xmodem.

I don't remember the difference between BYE or MBYE. I'm looking for a recommendation and pointer to the best/latest source code for a RCP/M. I have BYE 7.2 for a starting point. I'll want MDM 7.?? and XMODEM source too.

I'm not finding much code for the M6850 in MITS boards. The 8251A code uses software Baud rate selection, the Bitstreamer uses switches. I'm using CP/M MBASIC4 an Altair BASIC to initialize and test the M6850.

I'd appreciate any advice on source code versions and source, BYE RCP/M without a modem, and Ethernet to serial connections. I'm currently researching 88-2SIO configuration and ready to learn what signals BYE needs to work without a modem.

The back of my Altair has six 25-pin connectors:

Three connectors are VG standard Bitstreamer ports A, B, and C. - Ignore for now

One connector is a MITS Turnkey Module M6850 at 14H/15H for MITS BSTAM. Later, the port will be useful for an APE (http://frankbarberis.tech.officelive.com/default.aspx) modem program.

The last two connectors are for the MITS 88-2SIO console a modem ports. The MITS console only uses transmit, receive, and ground. The second port configuration is mostly undefined for MITS software. I think the default MITS handshaking and internal cable connections need some refinement.

My next tests are an Altair 8800 to 8800b RS-232 link from Albuquerque to Denver. Does anyone have an RCP/M system on the internet?

Tom Sanderson
http://tom12.tech.officelive.com/default.aspx

Dr_Acula
July 30th, 2010, 01:30 AM
That sounds very interesting. I'm not an expert in this but I have some things that will be useful to you and some of the things you are doing look very interesting.

About 12 months ago we had a N8VEM up for a week or two using a MSS100 serial to ethernet device. I've still got those ready to go and have the router configured for a fixed IP address, but the N8VEM was using a ram disk (448k) and it didn't have many files, plus it was possible to crash it remotely and then it needed rebooting. So I've had to go back to a more stable system, and that little project has taken a year.

However, MPM on the propeller is looking more stable now, plus it is possible to host around 50mb of files on an sd card. So I'm almost back to where I was last year. I'd love to have something up permanently - and also maybe make it "crash proof". It would be great to do a link-up.

Re xmodem, yes I have a source. Just need to patch three variables - input port, output port and input status port. Maybe patch the bit that changes when a byte is available on the input. I checked your link but not sure where the port addresses are.

Re "I can do console operation and file transfer without Telnet " - ie do you mean raw bytes in and out?

I need to find out more about these BBS programs. Could they do file transfer? My vague understanding of BBS programs were they run under an operating system and made the OS crash proof. eg on an OS you could upload a program and run it and it might be a program that just did a mindless loop and to the outside world the computer was broken. With a BBS that would be hard to do, right?

I'm not sure about sources but I think there are others here who can help.

virtualaltair
August 5th, 2010, 02:07 PM
>Re "I can do console operation and file transfer without Telnet " - ie do you mean raw >bytes in and out?

I'm using proprietary drivers that make virtual COM ports on Windows PC. The drivers have a TCP/IP connection to a remote serial to Ethernet server. The server is connected to the Altair console port.

I recently discovered that a PC terminal program can connect to the server with a standard TCP/IP connection.The standard TCP/IP connection had some character set problems, but could function as a Altair console without using the virtual COM port drivers or Telnet.

IPCOMserver can use the virtual COM ports to implement a Telnet server. I see little reason to use Telnet.


>I need to find out more about these BBS programs. Could they do file transfer? My vague understanding of BBS programs were they run under an operating system and made the OS crash proof. eg on an OS you could upload a program and run it and it might be a program that just did a mindless loop and to the outside world the computer was broken. With a BBS that would be hard to do, right?


I used some early BBS systems, but mostly visited RCP/M systems. Later, I used TBBS on PCs. I suggest you make you questions operating system specific.

CBBS was likely the first CP/M BBS. I don't remember much except that it had a lot of ASM code. I got a diskette from Ward, but was intimidated by ASM. I still have the diskette.

Next, I looked at RBBS. RBBS was written in Microsoft BASIC and could be compiled by the Microsoft BASIC compiler. I don't remember what function was in RBBS. I do remember that compiling a large BASIC system was work on a small diskette development system.

At this point my interest forked away from the BBS culture. I think a CP/M BBS might have a menu based file transfer option. My model was to use mini-RBBS. I had only minimum BBS message function. I also maintained a much smaller BASIC project.

The RCP/M BYE program would load and run the mini-RBBS. That provided welcome instructions, user communication, and logging. The assumption was that the caller would exit the message system to do file transfer and command line operations.

Think of my mini-RBBS as an remote only e-mail client.
BYE was desktop sharing.
XMODEM.COM was file transfer server.
Modem was file transfer client.

Modem 7 and MDM7xx were menu driven file transfer clients that included command line and utility program function as menu items. The file transfer clients became terminal programs that could transfer files using a RCP/M command line utility or a BBS File Transfer Area.

The BBS became the user interface for users not wanting to work at the command line. The RCP/M was mainly for developers to distribute and update source code. The BBS interface evolved more social and less technical.

The XMODEM.COM and Modem 7?? interaction was like cutting and pasting between shared desktops. A BBS was Facebook or a support forum.

A BBS or RCP/M was not crash proof. Loss of phone connection might trigger a reset. A constant voltage transfer would prevent many crashes on systems with a linear power supply. The clock board might need battery backup and a trickle charger.

The BYE program did protect from BDOS errors when callers selected a non-existant drive. A crashed system or a system in a loop would need a manual reset. Other options might be using a telephone answering machine remote control tone or an RS-232 signal for triggering a reset.

Tom

Altair 88-22SIO (http://tom12.tech.officelive.com/882SIO.aspx)
88-2SIO to GW312 External Cable Cable (http://tom12.tech.officelive.com/GW312toAltair882SIOCable.aspx)

altairsysop
December 19th, 2016, 02:41 PM
Fast forward six years to 2016 and I (virtualaltair) have an Altair RCP/M running. I (virtualaltair) lost my login information an re-registered as altairSYSOP.

The PMMI modem remains one of my favorite S-100 boards, however the internet and decline of the POTS telephone network make it less valuable. The PMMI modem is historically important, but there are now issues with speed negotiation and VOIP codecs. One land line is expensive considering the number of people with only a cell phone. A second land line was useful in the past and would be useful now.

RCP/M software exists for "AT" command set modems. I took the approach of using a "dumb" RS-232 connection without a modem. Mike Douglas modified BYE 2.74 to use a MITS Altair 88-2SIO port 2 with CTS enabled. The Altair RS-232 port connects to a GW312 Serial Ethernet server. The GW312 can connect using Virtual COM Ports or Telnet. Telnet is currently in use because it does not require installing virtual COM drivers

BYE 2.74 and XMODEM 4.7 combine to form a simple RCP/M with MINI-RBBS installed. The VirtualAltair.com RCP/M may be the Last RCP/M running. The Altair RCPM is running on an Altair Clone and a real Altair mainframe.

The VirtualAltair.com RCP/M welcomes callers and requests help upgrading BYE.COM and XMODEM.COM plus adding IMP/KMD, MDM740, and XMODEM software.

Telnet: altair.virtualaltair.com:4667 for the VirtualAltair.com RCP/M. Use MAIL.COM for MINI-RBBS messages.

Tom

altairsysop
December 19th, 2016, 03:45 PM
VirtualAltair.com RCP/M

http://telnetbbsguide.com/bbs/virtualaltair-com-remote-cpm/

Remote CP/M System running on Altair 8800 and/or Altair Clone. New system just getting started (Dec. 2016) using circa 1981 CP/M software. File transfer with XMODEM.COM and simple BBS using MINIRBBS. Run A:MAIL for message system.

Telnet: altair.virtualaltair.com:4667

Tom