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Tim's own version of the Catweasel/Compaticard/whatever

by CLASSICCMP＠trailing-edge.com

>Since soldering is so much more reliable, and just as fast once you get >used to using the soldering iron, I don't see the point of said >breadboards. But anyway... I've been using these breadboards for about 20 years now and I still like them for a lot of things. They certainly aren't good for all possibilities, but I regularly do digital logic into the 50 MHz range with them and have few problems. Modern CMOS logic families seem to be a lot more forgiving for poor bypassing and high-impedance power sources than good old-fashioned "straight" TTL. In fact, just for fun, I've pulled out *all* the bypass capacitors around a 40 MHz HC TTL circuit and found that it operated identically to before the bypass capacitors were pulled. Compare this to old-fashioned straight 7400-series logic where if I don't put bypass capacitors everywhere all the flip flops randomly choose a new state every time the clock ticks! On the subject of breadboarding with solder and wires: are there PC-boards designed specifically for "place-and-tack" surface-mount prototyping? I'm envisioning a power grid, a bunch of SOIC pads with small fanout, a place for some surface-mount discrete parts, and maybe some way of putting a header connector on the board. That'd be really useful. Sort of like those through-hole prototyping PC boards that used to be popular. Tim.

25 years, 11 months

Tim's own version of the Catweasel/Compaticard/whatever

by mann＠pa.dec.com

Let me interject a few notes about the Catweasel here. Quoting from Tim Shoppa's original message: > 1. The Catweasel uses some custom LSI parts, as far as I can figure out. It uses a PLD. The 1996 version, which I have, uses a MACH 211. I'm not sure what the new 2000 version uses; probably something similar. The PLD equations aren't released, though, so knowing this doesn't tell you much. > My circuit is much more "hackable", anyone with a TTL databook can figure > out what it does and improve on it. Or you can build one yourself from > scratch. (Other than the 128K*8 SRAM, all the other parts were literally > purchased from the local electronics shop. Heck, most of the chips can > be bought at Radio Shack!) Total cost for the chips in my buffer is > about $30.00, about half of that in the SRAM chip. I sympathize with that, but for those of us who are much better at software than hardware, something off-the-shelf is a big plus. You can get a Catweasel for $85 to $95 completely assembled. > 2. The Catweasel uses a proprietary, largely undocumented programming > interface. My circuitry is entirely open, and I think it's pretty easy > to program. (My first hack at acquiring data with the new buffer was > dashed off in about half an hour under QBASIC.) You can now get the documentation for the programming interface just by asking the designer (Jens Schoenfeld). He told me that it isn't secret anymore. The document is in German, but I could provide a translation if anyone needs it. (My German isn't that great, but the document is so simple you can almost read it without knowing any German.) There is also an open-source Linux driver, and the program I wrote for reading FM and MFM disks to one of the TRS-80 emulator formats (cw2dmk) is also open source. > 3. The Catweasel requires a bus slot inside a PC-clone. My new buffer uses > a much more general purpose parallel interface. So you can hook it up > to a laptop, or even to something that isn't a PC-clone at all. That's a real plus; on the other hand, if you do have a PC clone with an ISA slot, it's more convenient having the board inside the computer than hanging off the parallel port (especially if you're already using the parallel port for something else). > Those are what I see as advantages over the Catweasel. There are also > some disadvantages: > > 4. You can't just go out and buy my buffer, but you can buy Catweasels > off the shelf. > > 5. My buffer is strictly "read-only" as I use it. I think the Catweasel > (and Compaticard) both allow writing. Yes, the Catweasel allows writing. I haven't tried this yet, though. Another point to note is that the Catweasel samples at 7 or 14 MHz (software selectable). In reading some old 8" MFM disks, I found that there had been a lot of bit-shifting over the years (or maybe there was not enough write precomp applied to begin with), and I had to use an extra heuristic to make them readable at all. I'm not sure that 4 MHz would have been a high enough sample rate for these. Tim Mann tim.mann(a)compaq.com http://www.tim-mann.org Compaq Computer Corporation, Systems Research Center, Palo Alto, CA

25 years, 11 months

Tim's own version of the Catweasel/Compaticard/whatever

by CLASSICCMP＠trailing-edge.com

>One final point that perhaps Tim could answer. If he does provide a >schematic, would he have any objections if somebody else created a CPLD >(or FPGA, or..) version? Giving him full credit for the original idea, of >course. Because if he doesn't mind, then the whole issue goes away. You >can build whichever version suits you... The entire idea of discussing my circuit here was to get some ideas for improvements, *and* to make it clear that this was entirely an "open" hardware design and a "non-secret" programming interface. The circuit is hardly original enough for me to claim it to be my idea, especially as other manufacturers have been making proprietary interfaces that do the same thing for at least a decade. I wanted to make the design public so that it will last for longer than your typical PC-clone piece of hardware. Tim.

25 years, 11 months

Cipher Streamer / DEC TS05 Tape Drive

by dhquebbeman＠theestopinalgroup.com

> >It seems strange for the drive to look so otherwise perfect and > >these items to be mush. Any thoughts? > > Storage conditions, especially atmospheric ozone. I spent 6 years > living in LA, and the lifetime of my natural-rubber bike tires there > was measured in months. Foam would either dry up and turn brittle > or go the other way and turn gooey, typically within a couple of > years of manufacture. > > Obviously temperature and exposure to UV light/direct sunlight are > factors too. Well, heat I'd buy, but other areas of the drive would have shown the effects of sun, and the hub is inside, away from light. I was wondering what storing the unit in the presence of unsealed containers of petrochemicals might do... or even worse, whatever a medical school (formaldehyde?) might have in storage... -dq

25 years, 11 months

old Mac parts

by Marion.Bates＠dartmouth.edu

Hey, I have a friend who's interested in selling the following items, and he asked me to post this to the list. Reply to me if you're interested and I will put you in touch with him. -- MB ---------------------------------------- I looked at some of my junque and the only thing that is all together is one 400K external drive. I found 1 128K board, 1 128K board upgraded to 512 and one later 128/512K board set up as 512K. I haven't looked at all of the cases yet to see if I can make some 128's or not. I found some old HD20 parts that may be for the original, runs off the external drive port on a 512K (fat Mac), using a floppy to start up and recognize the hard drive. The only profile part is a controller board (I think - if I am remembering right). It's all in my basement. The three IBM PC Jr's are still in the garage and haven't been run in years.

25 years, 11 months

paging Will Jennings

by rigdonj＠intellistar.net

Will, I tried to reply to your message but the message was rejected. Check your return address. Joe

25 years, 11 months

Looking for....

by LFessen106＠aol.com

In a message dated 7/5/00 2:00:03 PM Eastern Daylight Time, rigdonj(a)intellistar.net writes: > Where are you? > > I know where there's a few located in central Florida. > > Joe > Eastern Pennsylvania. -Linc.

25 years, 11 months

FSOT: Perkin Elmer stuff

by rigdonj＠intellistar.net

Hi, I picked up a couple of blue three ring binders with Perkin Elmer logos on them. Both have manuals in them. One is for PECESS Software Packet for a UV/VIS/NIR Spectroscopy and has some printouts with BASIC listings. The other has a manual for Command Descriptions Reference Manual for CDS-3 Application program. Does anyone want them? I'll trade for something I can use like HP manuals, Tektronix 4041 manuals or ???? Joe.

25 years, 11 months

Cipher Streamer / DEC TS05 Tape Drive

by CLASSICCMP＠trailing-edge.com

>On my much-older and much-more-clearly-used Cipher on the Prime, >the rubber pads are fine; on this nearly-new-looking TS05, they >have lost all firmness and have turned almost to the consistency >of tree sap. They didn't drip, they weren't that bad; but one >attempt to load a tape left most of the pads on the inside of the >tape reel. > >It seems strange for the drive to look so otherwise perfect and >these items to be mush. Any thoughts? Storage conditions, especially atmospheric ozone. I spent 6 years living in LA, and the lifetime of my natural-rubber bike tires there was measured in months. Foam would either dry up and turn brittle or go the other way and turn gooey, typically within a couple of years of manufacture. Obviously temperature and exposure to UV light/direct sunlight are factors too. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

25 years, 11 months

Cipher Streamer / DEC TS05 Tape Drive

by dhquebbeman＠theestopinalgroup.com

Hello, The TS05 I picked up last week looked to be in perfect condition. There was very little dust on or in it. However, I did notice a slight amount of rust on the shaft coming out of the take-up motor (the top of the shaft is visible through the hub). On further inspection, there is a slight amount of oxidation on the surface of the takeup hub; this can be easily removed with Scotch-Brite, I think. But what disturbs me is this... I found one particular sign that this drive may not have been used for some years. The supply hub has three short arms which emerge from their normal position tucked inside the supply hub and which press against the inside metal rim of the tape reel in order to hold it in place. Each little arm has a small rubber or latex pad which helps to provide grip against the tape reel. On my much-older and much-more-clearly-used Cipher on the Prime, the rubber pads are fine; on this nearly-new-looking TS05, they have lost all firmness and have turned almost to the consistency of tree sap. They didn't drip, they weren't that bad; but one attempt to load a tape left most of the pads on the inside of the tape reel. It seems strange for the drive to look so otherwise perfect and these items to be mush. Any thoughts? Plus, anyone been there/done that? I need to replace these pads, and they weren't listed in the Cipher manual as a replaceable part (you have to replace the entire supply hub, it would seem). tia, -doug quebbeman

25 years, 11 months

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