On 2003.05.29 20:27 Jerome H. Fine wrote: I am not John, but this may be the explanation: The RX02 uses double density only for the data inside the sector. The sector header is (mostly) the same as a RX01 sector header and it is rcorded in single density. Result: A RX01 holds 128 Bytes per sector, a RX02 holds 256 bytes per sector, thus doubling the capacity. So the floppy controller has to switch the data rate from sector header to sector data... A really, uhhm, "interresting" design. -- tsch??, Jochen Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/

--- Jochen Kunz <jkunz(a)unixag-kl.fh-kl.de> wrote: That is, essentially, the case. A DEC drive can take an IBM-formatted floppy (RX01 format) and scribble the right things on it to make it an RX02 floppy, but only third-party drives (Data Systems Designs, et al.) can start with a blank floppy. Unlike "modern" machines, there is no "floppy chip" in an RX01 or RX02 drive - it's all done with TTL, PROMs and discrete components. When floppy controller chips became popular, they didn't spend a lot of time on "oddball" formats. The data-portion of the RX02 is what a PeeCee FDC can't digest. It *might* be possible to program an Amiga to digest RX02 disks (it also lacks a dedicated FDC - it uses a 4096-bit shift register in the sound chip to import the data, and (for MFM formats) miniterms applied by the graphics co-processor to translate back and forth to plain binary data). The Catweasel should be able to handle it, but, as has been hashed out here before, you'd have to roll your own with it; the software support is severely lacking compared to the capability of the hardware. -ethan

Jerome Fine replies: I have an DSD unit with a floppy (DSD 880/30) and have performed an LLF on an RX02 media. But I did not know that the PDT-11/150 was also able to do an LLF as well. Thank you! However, does the PDT-11/150 use an actual DEC RX01 floppy drive or something a bit different? With the answer to this question, it should be possible to determine if the RX01 has some of the smarts to do an LLF, but when connected to a Qbus RX01 controller, the combination is not capable - OR DEC did not make public the command codes to cause the RX01 drive to do an LLF? Please confirm that the PDT-11/150 uses ONLY RX01 media. ALSO, is the device driver for the PDT-11/150 the PD.SYS file? I seem to remember that the PDT-11/150 did NOT have a hard drive, is that true? If the PDT-11/150 does have a hard drive, which hard drive and what is the name of the file for the device driver? That was the essence of my reply above with the two different commands under RT-11 using a DEC RX02 floppy drive. What would be helpful is is you would confirm (or deny - since I am always making mistakes) that the FORMAT command under RT-11 for 8" floppy media on a Qbus/Unibus system ONLY sets the density bit in the sector header of the media. BUT, before that can be done, a successful LLF must occur with that media. The DSD 3rd party floppy drives were one method. You have confirmed that a PDT-11/150 is a second method. While I have no doubt that the PDT-11/150 can do an LLF on an 8" floppy media and your demonstration was evidence of that fact, I do not agree that it was proof. I have, on many occasions, had an 8" floppy which I could not read on a DEC RX02. It had already had an LLF, but all attempts to read the media were unsuccessful or unreadable. On a Qbus PDP-11/23 with a DEC RX02 drive, I used the RT-11 command: FORMAT DY0: and it was successful and I could again read the 8" media. So while the magnet would likely do a bulk erase, it is not proof that it was done and that an LLF was required - yes 99.9% of the time I would agree it would be necessary, but very rarely it might not. You mentioned that a few years ago. Did the LLF process use the RT-11 command or was XXDP used? Since I can't remember if XXDP ran on a PRO350, I am curious. Also, I just remembered that a Rainbow could also do an LLF on an RX50????????????? Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.

--- Martin Scott Goldberg <wgungfu(a)csd.uwm.edu> wrote: There was a game for the PET that linked user ports that was available years before the ST came out. It was well documented in Byte magazine. I never bought it because I had only one PET. Each player had a fixed base and a roving tank. The goal of the game was to lob an ICBM on the other player's base. You located it by exploring with the tank. I cannot recall the name at the moment, but it's come up for discussion on the list before. Beware making "first" claims. There's frequently an antecedent. -ethan

On Sun, 1 Jun 2003, Fred Cisin (XenoSoft) wrote: Another one is TelePong on the Apple ][. It was one of their very early software releases and came with their original serial card. It allowed you to hook two Apple ]['s together through either a null modem or a modem connection and play Pong against a remote opponent. I plan to exhibit this at a VCF some year. Maybe this one. Hmmm, a good theme for this year's VCF would be "Networked Computer Games through the Ages". Hmmm... -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org * Old computing resources for business and academia at www.VintageTech.com *

It was thus said that the Great Ethan Dicks once stated: I thought of that as well (it was the December 1980 issue of Byte by the way, and later one it became Flash Attack available on the MajorBBS) but I discountd that as I thought it used the serial port to hook only two machines together; technically that may make it a "network" but not in the general sense of the word (multiple machines). The article itself was written by Tim Striker and someone else I don't recall and pretty much worked as described. Later on, Tim founded Galacticomm, which started out as a hardware company making multi-port serial boards but switched to software when one of their demo program, the MajorBBS, because a hit. I the late 80s, Tim (or maybe it was Scott Brinker [1]) rewrote Flash Attack for the MajorBBS. I even wrote a program [4] to help me play the game (which was encouragd by the company as they realized people would cheat, so they made the cheats available 8-) -spc (Interesting game ... ) [1] Nice guy, but wierdly intense in that optimistic Richard Simmons type of way. I first met him in the late 80s/early 90s when he was still in high school running one of the larger dialup BBSes in Ft. Lauderdale; this was when Flash Attack came out. A few years later in the mid 90s he became President of Galacticomm and during his stint the MajorBBS was being ported to Unix [2] and I was hired to help the port---I ended up quiting two weeks later over differences in coding styles [3]. [2] http://www.kenmaier.com/gcomm/mbbsunix.htm [3] They used K&R style and actively discouraged comments; no function or global variable could not be longer than seven characters (ANSI C89 limit, but realistically the compilers they used allowed more) and they themselves could not rationalize *why* they enforced that style (other than, that's what Tim, Scott and Bob [Stein] were used to). My arguments were dismissed, then so was I. [4] Still have the code and it works for both the PC and PCjr [5]. It was also smaller, faster, less intrusive (it was NOT a TSR) and did not require floating point math, unlike the program written by Galacticomm itself. I could also beat people dialed in at 1200 than those dialed in as 2400 ... [5] Subtle differences in how the keyboard interrupts work; enough that you have to code around them.

On Mon, 2 Jun 2003, Alan Greenstreet wrote: So this would have been in 1984 maybe? -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org * Old computing resources for business and academia at www.VintageTech.com *

--- Sean 'Captain Napalm' Conner <spc(a)conman.org> wrote: Thanks. I *thought* it was in 1980, but I wasn't certain enough to claim it. PETs don't come with serial ports. The VIC-20 and C-64 had ROM code to give you a bit-banging TTL serial port up to 1200 baud, but that came after the PET. The Flash Attack communication protocol uses a custom cable that transfers a nybble with full handshaking. One end of the cable also has a specific pin grounded (the other end is floating) to allow the computers on either end to determine who sends first. I made a similar cable and used it extensively to transfer data between my C-64 and my PET in 1982, long before I got a 4040 drive. All you need for a network is two machines. I've attached several VAXen over point-to-point sync serial links and run DECnet over them. Multiple machines and routing (or token passing) is another level of networking, to be sure, but that doesn't disqualify a network with only two endpoints. -ethan