fjmora@CS.WM.EDU (Fredric Mora) (08/01/89)
In Info-Atari16 Digest V89 #344, Larry Rimal writes: >As a side note, hardware hackers love the ST. Easy to modify, tough >as nails, and quite versatile, it is a joy to play around with. All that >is missing are slots! ^^^^^^^^^^^^^^^^^ I definitely second that. In fact, I sent a mail to John Townsend at Atari about the possibility of Atari making an expansion box for the Mega ST. Such a box would have a slot plugged in the Mega internal connector and reproduce the connector (say, 4 to 6 slots) in a Mega-like box. John answered briefly: >It has been suggested before.. however, I think it is harder than it >sounds.. > >-- John The following is my detailed answer to J.T. explaining why I think it's not complicated at all. Please feel free to flame me if you think what I say is wrong. If you agree with this expansion box suggestion, please make sure some people at Atari know it (for example, E-mail to JT at portal!atari!towns@uunet.UU.NET). Ken Badertscher and Allan Pratt seem to be more software oriented, I am not sure that this should be sent to them. I think that such a peripheral is now needed by ST users and that Atari could sell it and make money while responding to users' wishes. I know that Atari wants us to upgrade to the TT and buy VME boards when it becomes available, but I don't want to trash my ST for a new toy, even a nice one. I welcome any feedback. ---------------------------- >To: portal!atari!towns@uunet.UU.NET >Subject: Re: A little suggestion Thank you very much for your answer about my suggestion of a bus extension box for the Mega ST. You write: >It has been suggested before.. however, I think it is harder than it >sounds.. > >-- John Certainly, I agree. First, the box would have to include a power supply (say, 65W. Costs $39 in retail PC-compatible shops). Careful connection of the 2 grounds (the Mega's and the box's) is required. That can be done, at least by dealers. Second, we are talking about plugging a connector into the internal Mega slot and sending the signals on a backplane. This requires buffering the 68000 bus and shielding the box. The designers would probably need to alternate each signal with a grounded trace on the printed circuit board for better noise immunity. Also, mechanical shielding problems may appear and need to be addressed carefully because of the FCC standards. I don't think that this is a major problem. It's more a mechanical design problem than an electrical engineering problem. Thus, it seems to me that this extension box could be designed and marketed without major troubles. After all, no software revision or hard architecture change is considered. Maybe there is a major problem that I do not see here. Please feel free to flame me if I forget an important technical detail. And as more and more cartridges or boards are competing for the cartridge slot of the ST or the internal connector of the Mega, the customers will increasingly feel the need for this bus extension box. It would give ST owners a reason to upgrade to the Mega ("Tired of plugging/unplugging your Spectre, sound digitizer and video digitizer cartridges? Here is the solution," the ads would say) that they don't really have now (they make good RAM extension boards for the ST, why should I get a Mega just for more RAM?). Also, don't forget that the European market already offers two uncompatible "standards" for this kind of extension boxes. I can send you the ads in the German "ST-Magazin" and the French "ST-Magazine" if you want a proof. This actualy hurts the ST, like all incompatibility problems. It's about time Atari Corp. pushes its official standard, the Mega bus board format, and support it with such an official extension box. Developpers would feel much more confident. Than you for your consideration. Regards, Frederic Mora GEnie: The College of William and Mary F.MORA Dept. of Computer Science INTERNET: Williamsburg, VA. 23185 fjmora@cs.wm.edu USA ************************************************************************** * "Was uns nicht toetet, macht uns staerker." - Friedrich Nietzsche * * What does not kill us makes us stronger * ************************************************************************** - Come, come, little line eater, I won't harm you (evil grin)...
jbww@ukc.ac.uk (J.B.W.Webber) (08/04/89)
In article <8908010836.AA07638@nh.cs.wm.edu> fjmora@CS.WM.EDU (Fredric Mora) writes: >In Info-Atari16 Digest V89 #344, Larry Rimal writes: >>As a side note, hardware hackers love the ST. Easy to modify, tough >>as nails, and quite versatile, it is a joy to play around with. All that >>is missing are slots! > ^^^^^^^^^^^^^^^^^ > >I definitely second that. In fact, I sent a mail to John Townsend at Atari >about the possibility of Atari making an expansion box for the Mega ST. Such >a box would have a slot plugged in the Mega internal connector and reproduce >the connector (say, 4 to 6 slots) in a Mega-like box. >I think that such a peripheral is now needed by ST users .... > >John answered briefly: >>It has been suggested before.. however, I think it is harder than it >>sounds.. > >Certainly, I agree. > >First, the box would have to include a power supply (say, 65W. Costs $39 >in retail PC-compatible shops). Careful connection of the 2 grounds (the Mega's >and the box's) is required. That can be done, at least by dealers. > >Second, we are talking about plugging a connector into the internal Mega slot >and sending the signals on a backplane. This requires buffering the >68000 bus and shielding the box. The designers would probably need to alternate >each signal with a grounded trace on the printed circuit board for better >noise immunity. Also, mechanical shielding problems may appear and need >to be addressed carefully because of the FCC standards. I don't think that >this is a major problem..... > > O.K., can't resist putting my ha'porth in, here. First I must say that I am as keen an enthusiast for rack systems as you will find. I have been designing and building laboratory instrumentation hardware/software modules into 19" racks ever since the 6800 and 8008 first appeared, using a number of processors (including the 68000) and maths processors. (Yes, Virginia, before the 68000, came the 6800, 6802, 6809 ...) However, on my desks there are now STs - how come ? I guess the answer is that a rack costs - not just money, but also time, documentation, care of edge connectors, construction of multi-way cabling to instrumentation, etc. Does one site the computer at the experiment (which part of it), or take the signals to the computer ? ( I have seen some people's experiments end up with half a dozen computers scatterd over a room.) So, is a rack system such as is proposed for the ST possible ? Sure. Is it optimal ? Perhaps, five years ago, not now. (See above, for reasons.) For a start, the 68000 is dirt cheap (a few pounds); by the time one has payed for all the hardware, one might as well add a processor. Now one is talking about another computer, so how are the two to communicate ? I use serial port/midi port quite frequently; these are often enough for sending commands and occaisional data. For good data rates, one wants something more; the ST DMA port is a natural. I have looked closely (logic analysers, etc) at the ST DMA port, but was not able to get solid enough documentation to spend time on it. I may yet return to using this, but one of its real limitations is that it only allows for one master. Thus a SCSI bus interface will probably make more sense, if one is after a high performance multi-wire systems interface. (I do have IEEE488 available from my racks, but don't fancy that I now have the time to write the ST end of a multi-tasking driver.) A SCSI approach is still quite complex, and pricey; I have only just upgraded to a SCSI hard disk on the ST at work. So, what path am I following ? Transputer Links. For those who have not met them, Transputers are a range of processors, (16bit to 32Bit), with 4 communications links integrated on the chip, together with, in particular versions, other resources - floating point processors, disk handlers, varing amount of memory, etc. Links run at 5, 10, 20 Mbit.s-1 (selectable), and an 18 pin DIL chip is available to provide a link-to-8bits-parallel interface. This makes them cheap enough to put with single chip controllers, to interconnect instrumentation dispersed around the experiment. The link connection is just two twisted pairs, one for each direction. Most importantly, a cartridge plug-in for the ST can be done for well under 100 pounds. O.K., the ST can't support 10 MBits in/out from the cartridge, but it is good enough for most things (all transfers are acknowledged, so data is not lost). The original version of the ATW (the Mega supported ABAQ) provided a link adaptor on the Mega internal 68000 bus connector; this is undoubtedly a very good way of doing it. For high performance interconnection and greatly increased processing power, one can add transputers at nodes; each link may only have two ends - this follows from the fact that transfers are acknowledged. I guess what I really like is just the two twisted wires, and cheap interface. 10 Mbit.sec-1 is about 1MByte.sec-1, and I don't try and send data at 1MByte.sec-1, down more than a few meters of multiwire cabling. The rest is all bonus. Hope this gives people some ideas; sorry for rabbiting on for so long, cheers, beau webber jbww@ukc.ac.uk University of Kent, Physics Lab.
terry@saxon.HAC.COM (Robert Terry) (08/18/89)
This is my first post to any news-group here. :) I recently obtained a quite a few files from comp.binary.st (sp?) to run on my ST Mega machine. Undecoding the files was the easy part. I wasn't able to "extract" the sub-files from undecoded files. When it failed each time, it said that I need a newer version of "ARC.TTP". Could anyone out there please direct me to the ftp address and obtain the most recent arc.ttp program? Thank you very much! :) Please reply by email. As of now, I have 382 messages to catch up on this news-group!! :] My email: terry@tcville.hac.com P.S. I hope I didn't goof here! :) Robert Terry Hughes Aircraft Co. TDD: (213) 616-6846 Image and Signal Processing Lab email: terry@tcville.hac.com PO Box 902, E53/E250