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Program Challenge (was Re: z80 timing... 6502 timing)

by spc＠armigeron.com

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27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

--- Sellam Ismail <dastar(a)ncal.verio.com> wrote: > On Mon, 19 Apr 1999, Ethan Dicks wrote: > > > I wish I had one of the stereo inspection microscopes... > > I have a similar device that was used for inspecting ICs. Its basically a > microscope with a fine adjustment platform... That's it. The one I'm thinking about has optional air bearings that can be clamped down with a foot pedal. You clamp the board into the frame, drag it around like a microfische, then lock it into place with the pedal. The field of view is adjustable, and can zoom in to entirely encompass a 1/4 W resistor or out to encompass several SMT ICs. > I assume you are thinking to replace the wire strand completely, and not > attempt to solder the two broken ends together? I need to get some pictures of this... Imagine a core plane... ||||||||||||||| --///////////////-- --///////////////-- --//XXX//////////-- --///XXX/////////-- --///XXX/////////-- --////XX/////////-- --///////////////-- --///////////////-- With the X's representing physically broken and/or absent cores. On my particular board, each bit of 4096 cores is a square approx 2" on a side (about 1/32" per core site), with the damage to two bits on the same edge of the PCB. I was originally planning on lifting the X and Y wires from one corner of the bit to be repaired, unthreading the cores only where necessary, and making any splices to the sense/inhibit wires at the edge of the core (as I belive there already are). If I scavenge wire and cores from the parity plane, I have more than enough raw material. If I attempt to sacrifice one bad bit for the other, I don't have the surplus wire (the X and Y wires must be preserved from edge to edge of the core PCB) I have just thought of another, more devious method, but on second thought, it would have to be clever indeed... Change the diode board such that the damaged bits are not both accessed at the same time (i.e. X32, Y16 on plane D4 is broken, but X32, Y16 on plane D3 is _not_ broken) and convert the two broken bits into two fields of 2048 cores each (and use the parity bit intact). It turns a 13-bit memory into a memory of 11 intact planes and two half-planes. I'll have to study the geometry to see if this is possible. Alternately, if the individual columns are intact, I could do sort of a "one from column A, two from column B" approach. As long as the sense amps don't balk at the extra resistance of doubling the length of of the sense wire, it could work. -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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Repairing core (was Re: How scarce (valuable) is core for the PDP-8?)

by allisonp＠world.std.com

<Do you have an opinion on how historically accurate is reasonable to <attempt? By this I mean that the parity plane (all by itself on a 3/4 <empty PCB) has no damaged cores. If I move the sense/inhibit wires from <its slot on the paddle boards, I can borrow them intact to act as one of <the damaged bits, I can then disassemble the more damaged plane (or perhap <the less damaged plane depending on where the damage is easier to get to) <and only have to repair _one_ plane. Your odds of success are much higher and it will be far less difficult. <In short: more like the original - disassemble the parity plane, removing <it from the stack, converting a 13-bit broken stack with 4 PCBs to a 12-bi <working stack, or, disassemble a broken plane, swap the data wires from it <to the parity plane, keeping all four PCBs inside the stack. The second <solution seems to make more sense from an effort and safety standpoint, th <first solution seems to me to be more "pure". In the era, if it were not used for parity (that wasn't common) then plane would then be considered "spare". Since an 8L was maxed (it could be hacked larger) as a 8kw machine that would be a nice box. Allison

27 years, 3 months

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FS: Russian computer

by adavie＠mad.scientist.com

I've been offered a Russian Computer - "So, the computer 'Elektronika MS-1502' is IBM-compotable, it likes IBM PC. It has a monitor, a memory volume 512 kb. It works with using a recorder, but if there is a device it can work with using a drive." This is probably too big for me, and sideline to my interests. If there's anyone on the list who would like to arrange to buy this machine from it's owner (it will be relatively cheap, I'm sure), then please contact me privately on adavie(a)mad.scientist.com and we can talk about your needs. You will, of course, have to arrange shipping out of Russia. I can handle payment for you. I have no financial or other interests in this machine, other than trying to find a buyer as a favour for this Russian gent who supplies me with calculators. Cheers A

27 years, 3 months

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Repairing core (was Re: How scarce (valuable) is core for the PDP-8?)

by CLASSICCMP＠trailing-edge.COM

>Unfortunately, my rant is not going to stop the lame-o's selling it from >hyping it up as some cool collectable, and it's not going to stop the >techno-wannabees from buying it to stick on their wall. Just wanting to point out that "display core" isn't a completely new phenomenon: Historically (going back at least 15 years), folks leaving the labs where I've worked - either retiring or moving on to other jobs - have been presented with core planes from machines that they worked with as "going away presents", frequently framed and behind glass. Ah, the memories!

27 years, 3 months

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Program Challenge (was Re: z80 timing... 6502 timing)

by KFergason＠aol.com

In a message dated 4/19/99 4:12:54 PM Central Daylight Time, cisin(a)xenosoft.com writes: > I must be missing something here. 9 does NOT produce the longest string > < 10, 8 does. (IX v VIII), and 3999 isn't the longest string. > > 3888 would seem to produce: > M M M D C C C L X X X V I I I \0 > which is 16 characters, including null. > > BTW, what comes after M? Is it correct that in Roman numerals there can > never be 4 consecutive occurences of the same letter? (The original Y4M > "bug"!!!) > No. Apparently the modern usage of Roman numerals is different than the Roman usage. Romans were known to do VIIII to mean 9, and were not really consistent in their usage. Interesting article in the Houston Chronicle discussing this a couple of months ago. 1999 can be made at least 3 ways, so a decision had to be made on which way should be used. (Hollywood movies, etc) Kelly

27 years, 3 months

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Repairing core (was Re: How scarce (valuable) is core for the PDP-8?)

by ethan_dicks＠yahoo.com

--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote: > > I kicked off this whole mess with... > > > > I have a chance to buy a 4kW core stack for the PDP-8/i (-8/L). It's > > more than I want to pay, $100. Then --- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote: > > Well, I've not bought core for a few years, and I payed a lot less than > that. Me, too. > But I believe core is now soemthing of a collectable (alas by > people who are not going to use it :-() Sigh. :-P > [...] > > > OTOH, I do have a broken (20-30 fractured cores) -8/L stack that I've > > contemplated repairing. It's a parity stack, so I can scavenge wire > > and cores from the parity plane (or just use the parity plane intact > > as another bit, then use one pad of broken core to repair the other, > > less damaged pad of broken core). > What I would do : > > I'd buy the core at $100, since that way you do have the working 8K for > your PDP. Then I'd try to mend the broken core plane that you already > have. If you fail, well you still have a machine with 8K in it (you'd be > kicking yourself, I think if you couldn't fix the old core and couldn't > still get a replacement). It seems the prudent thing to do, I was mostly just writhing about having to pay double of what _I_ think it's worth. I was polling for a sanity check to see if my expectations were unreasonable, or if the expectations of those stick-it-on-a-bookshelf collectors were. > If you do manage to mend it (and I think it's possible to re-string > larger-sized cores by hand) These are fairly large... much larger than on a 4kW stack for the PDP-11/20, but that's a three-wire plane. > then either make a 12K machine (if you can do that)... Not inside the -8/i (massive backplane, room for CPU, EAE, 8kW core and lots of I/O options. The -8/L expansion box _might_ take a total of 8kW) > or sell one of the core units to another collector (and if $100 is > the going rate you could probably get that for it). Or, of course, keep > it as a spare. I vote spare unless the price of core soars by one or two orders of magnitude. > > of time spent, it's cheaper for me to work a few hours and earn the money > > that the core pirate wants; in terms of lessons learned, repairing a > > 30-year-old core stack would be a big thrill, *if* it worked. > > Sure. Fixing old computers rarely makes financial sense, but then hobbies > rarely do. If I were in this for the money, I wouldn't be in it for the money. :-) > But learning how to mend core memory is an interesting thing > to learn to do IMHO (if I had a broken core unit you can bet I'd be > trying to fix it...) Do you have an opinion on how historically accurate is reasonable to attempt? By this I mean that the parity plane (all by itself on a 3/4 empty PCB) has no damaged cores. If I move the sense/inhibit wires from its slot on the paddle boards, I can borrow them intact to act as one of the damaged bits, I can then disassemble the more damaged plane (or perhaps the less damaged plane depending on where the damage is easier to get to) and only have to repair _one_ plane. In short: more like the original - disassemble the parity plane, removing it from the stack, converting a 13-bit broken stack with 4 PCBs to a 12-bit working stack, or, disassemble a broken plane, swap the data wires from it to the parity plane, keeping all four PCBs inside the stack. The second solution seems to make more sense from an effort and safety standpoint, the first solution seems to me to be more "pure". Thoughts? -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

--- Lawrence LeMay <lemay(a)cs.umn.edu> wrote: Someone else suggested: > > I'm not sure I do, either. Maybe he means Charles Lasner, a frequent > > contributor to alt.sys.pdp8 (aka PDP8-LOVERS) up until a few years ago? > > Bingo, Thats who I meant. Charlie is indeed most wise, if you can read through his reams of detailed answers. I have always found him to be a great help in ferreting out bizarre tidbits of trivia. Having been to his house in Queens, I can say that he does have quite the wide range of hardware knowledge, but I think even he would blanch at attempting to disassemble a core pad and scavenge the bits (literally) to repair a broken plane. I know I'm intimidated by the prospect, but I figure worst case I broke something that was already broken. I wish I had one of the stereo inspection microscopes that I used when I worked on the factory floor at a Lucent plant in Columbus. It has a sliding base and an optional pneumatic pedal to fix the jig in place. We used it to inspect solder fillets on SMT edge connectors for circuit packs (the AT&T name for a PCB) for phone switches. If I had one of those for a month, I could probably get the view necessary to attempt to thread hair-fine wire through the cores. I do have a Weller temp-controlled iron to avoid scorching the PCBs and I do have a 1/64" tip for it (normally, I use a 1/32" tip for general SMT rework). The only hard problem I have is how to test the memory without assembling the entire plane first (due to the interconnections between the diode matrix boards and the individual core plane PCBs). Someday, when I have better tools and *lots* of free time... -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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z80 timing... 6502 timing

by edick＠idcomm.com

I don't know why this has to be so complicated. There need to be constraints in order to ensure a level playing field, but since there are two related objectives, (1) to find out which of the two processors in the title of this message is "faster" and (2) to generate the fastest code for them for comparison. If people want to perform the exercise on other than these two processors, that's fine. It might show that the quality of the code makes more difference than the relative speed of the processor, which shouldn't surprise anyone. It wouldn't hurt, at least. It won't show what the fastest, leanest, most efficient, or any other comparative of the various ways of coding the problem would be for those two processors unless there's 1:1 mapping for the instructions, however. Having more attempts submitted will undoubtedly teach someone something and that's good. What it will also do, is show everybody more innovative approaches to solving the problem. Dick -----Original Message----- From: Fred Cisin (XenoSoft) <cisin(a)xenosoft.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 18, 1999 5:20 PM Subject: Re: z80 timing... 6502 timing >> > >Sure! Let's have a driving contest to see who can drive the fastest, but >> > >first we all have to build our own cars. THAT MAKES AN AMAZING AMOUNT OF >> > >SENSE! >> > Shsssh! We're building a race track first. >> No, that's too simple. First we have to go terraform Mars so that we can >> build the race track there. We don't want to give anyone an unfair >> advantage by letting them race their cars in a familiar atmosphere. > >I'm having a little bit of difficulty with not being able to use modern >tools and materials for the metallurgy for building my engine. :-) >Will I have to build it on Mars, also? > >If you really want to see a drivers only contest, watch IROC racing (was >just on ESPN this afternoon) - a dozen identical cars, and in 40 laps, the >pack spread out to a few car lengths. The winner was a Pontiac. So was >the loser, and every other car in the race. I think that it is more fun to >watch an event where the vehicles differ. > >We really need two sections of the whole competition - one section with >fixed platforms, and one section permitting custom hardware. >

27 years, 3 months

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IBM Optical drive questions

by SUPRDAVE＠aol.com

In a message dated 19/04/99 17:16:44 Eastern Daylight Time, roblwill(a)usaor.net writes: << My other question is if Optical disks are re-writable? I've talked to two people, and one of them says that Optical disks aren't re-writable, mangeto-optical disks are. The other person said that no optical disk is re-writable, and that only floptical disks are (isn't that a form of optical disk?) >> the type 3431 is rewritable. the 3363 is write once- read many.

27 years, 3 months

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Program Challenge (was Re: z80 timing... 6502 timing)

by mbg＠world.std.com

>> You naughty _naughty_ programmer! That's not at all in the spirit of >> the competition! >> (Wish I'd thought of it.) > >shhhhhhhhhh! Now they'll try to plug up the look up table loophole. > >Y'know, if the rules don't SAY what it has to be, ... The rules don't say you can't... but you do have to account for all memory used, for code and data... I've coded a version for pdp-11s, but since I have yet to test it (though of course it will work first time :-) I'm not going to post it yet... It takes up 62 words (132 bytes), uses 4 words on stack and 9 words of pure data space... when I've actually gotten a chance to try it, I'll be able to report how many instructions it takes to do the conversions (I suspect '1' is minimum and 3888 is maximum). I don't know how to check on number of cycles, though... The algorithm is pretty straightforward... converting to Roman is the same as converting to decimal except that once you have the digit for a given power-of-ten place, you convert *that*... I wrote it before looking at the code which was posted, and I suspect the algorithm is similar with the exception that I don't have a lookup table for the digits... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

27 years, 3 months

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Program Challenge (was Re: z80 timing... 6502 timing)

by yakowenk＠cs.unc.edu

] How much memory is used can be defined in two ways. (a) the number of ] bytes, and (b) how much contiguous memory must be present in order to allow ] the code to be implemented. It requires 200 bytes of RAM is not a valid ] statement if that RAM has to be scattered over a 32-KByte range. ... Worrying about using 32K? For a simple little Roman Numeral pro... uh... <* light bulb goes on *> You naughty _naughty_ programmer! That's not at all in the spirit of the competition! Bill. (Wish I'd thought of it.)

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by lemay＠cs.umn.edu

> When I mentioned the chance to buy a 4kW stack for the PDP-8/i for $100... > > --- Lawrence LeMay <lemay(a)cs.umn.edu> responded: > > > Actually, that's probably a reasonable price. > > Foo! Well, I didnt say that I would pay $100... Or that it was a great price. But it might be a fair price. Of course, If i didnt already have a bunch of core of various types, and if i needed it to restore a pdp8 system (which would be at the absolute top of my list to do, as the first computer I ever saw, and every used, was a PDP8/e) then I would probably pay it. And i'd be cursing at whatever the past 20-30 years had done to make the board not work anymore ;( And i'd probably try to locate Lassiter and see if my some miracle he could repair the board, etc. But, thats just me. To me, having a PDP8/e is the ultimate dream machine. That, and having the room to store a PDP8/e... -Lawrence LeMay > > > Core memory boards, probably non-working, have been going for a high price. > > I got sniped for a PDP-11 double-core stack this weekend, backplane included, > that went for $38, no reserve. > > > Age and a nice visible setup increase the price. > > The core stack for a PDP-8(i|L) is older than much of what's on the > market, but none of the good stuff is visible at all on it. > > > Now, I havent seen the memory in question. but the pdp8/e core > > memory i've seen is all covered by a clear plastic shield. This > > increases its value as a display piece, as you can easily see > > all the core, and its all protected. > > It's hard to describe the arrangement, but the core plane in question > here is a block with two edge-connectors on either side, "dual-height" > as they say, but it's much thicker - let's try bad ASCII art to illustrate... > > > ######## ######## > xxxxxxxxxxxxxxxxxx == ######## ######## > ######## ######## ######## ######## > > core planes paddle-boards with wire harness > > The outside of the core plane part is covered in a "diode matrix", with > a wad of twisted-pair wires that go off to paddle-boards, one for the > sense bits, one for the inhibit bits. The address lines come up the diode > boards, the data comes up and down the paddle-boards. > > There are several PCBs with core in the core stack, 4-bits per layer with > an optional parity layer that has one pad of bits and three pads of core-less > X-Y wires. None of this is visible when the plane is assembled, and it's > soldered together with lines of wires going up and down the planes. > > > Of course, in order to use the core on a pdp8/? you would need > > a couple of support boards in addition to the core plane board > > itself. I would say that just the core plane, being of a nice > > size, and being very good 'visually' to display, and somewhat > > because its a PDP8 series board (nostalgia value), that its > > probably worth $100 all by itself. If it comes with the 2 support > > boards and the top connector things at that price, then i'd say > > its a bargain. > > You are thinking of newer hardware. The pre-OMNIBUS 8's have a wad of > individual, single-height cards that contain the sense-amps and the inhibit > drivers. I have a pile of them from an -8/L that someone else had already > begun to strip for parts before I bought it (it also happens to contain the > only DEC lock that does *not* use the XX2247 key). I'm not worried about > the analog stuff... I need the core. > > Of course, as Allison pointed out, I could always stick in a lump of battery- > backed static RAM. I was contemplating building a wiring harness to adapt > an RX8E on the back of either an -8/L (which has 8kW of core out of 12kW in > an expansion cabinet) or on the -8/i. I would use berg connector pins to > stick the wires on the back side of the backplane (to avoid soldering, of > course; but worst case, I just wire-wrap on a connector or two and use > sheilded ribbon to move the signals around. > > The joys of restoration in a market of scarcity. :-P > > -ethan >

27 years, 3 months

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Q-Bus and Unibus to ATA info

by clintw＠colorado.cirrus.com

> From pechter(a)pechter.dyndns.org Mon Apr 19 14:06:36 1999 > Reply-To: classiccmp(a)u.washington.edu > Sender: CLASSICCMP-owner(a)u.washington.edu > Precedence: bulk > From: Bill Pechter <pechter(a)pechter.dyndns.org> > To: "Discussion re-collecting of classic computers" <classiccmp(a)u.washington.edu> > Subject: Re: Q-Bus and Unibus to ATA info > In-Reply-To: <011101be8a92$47a92bc0$5d01a8c0(a)p2350.ecubuero> from emanuel stiebler at "Apr 19, 1999 12:27:26 pm" > MIME-Version: 1.0 > Content-Transfer-Encoding: 7bit > X-Phone-Number: 908-389-3592 > X-OS-Type: FreeBSD 3.0-Stable > X-Listprocessor-Version: 8.1 -- ListProcessor(tm) by CREN > X-Lines: 33 > > > > >On the other hand, I have been pondering the development of a ATA > > >drive controller that emulates MSCP (and possibly TMSCP). > > > > I'm sitting on the layout of one ;-)) > > > > Problem is, you pay appr 100$ license fee for MSCP, and another 100$ for > > TMSCP. > > > > emanuel > > > I'd pay $200 + parts for a board that would do MSCP and run my 11/23's > with an IDE drive. > > Actually, I'd love to find a SCSI or IDE controller with DEC OS support > for the QBUS. > > > Bill Take a look at the CQD-220/TM or CQD-240/TM at www.cmd.com. I have two CQD-240/TM that I bought recently (25-Jan-99) from Ficomp (www.ficompinc.com), that I am using in my uVAX II with Ultrix 3.1. These boards emulate MSCP and TMSCP. According to the technical manuals on CMDs website, these boards work in: LSI-11/23, PDP-11/23+, Micro-PDP-11/53, 11/73, 11/83, 11/93, uVAX II, uVAX III, VAX 4000 and DECSystem 5400 systems. They support RT-11, TSX, DSM-11, ISM-11, RSX, RSTS, VMS, UNIX, ULTRIX, and other operating systems which use DU/TU drivers. I am happy enough with the ones I have, I am going to buy a Unibus one for my 750 when it arrives. clint

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

I have a chance to buy a 4kW core stack for the PDP-8/i (-8/L). It's more than I want to pay, $100. My question is, what are these things going for these days? I don't really *need* it. The guy selling it has more core than this that he saved from a "recycler", but he's in it for the money, not out of a love for classic machines. Most of his memory, he sells to people who want something to stick on the shelf and "ooh" and "aah" at. :-( So... for those people who have been trying to get core over the past year or two, what's it costing? I'm trying to decide if I want to grab this stack to put into my -8/i and bring it up to 8kW, an entirely optional project (I have all the other parts I would need for the upgrade from a PDP-8/L that I got in 1982 that was sold as parts-only, bad core, and most of the I/O and part of the CPU missing). I think he's charging too much, but maybe I'm disconnected with the current pricing. I do know that if I pass on it, there are several other people who are waiting for this exact piece, so it'll be sold one way or the other when I answer him. OTOH, I do have a broken (20-30 fractured cores) -8/L stack that I've contemplated repairing. It's a parity stack, so I can scavenge wire and cores from the parity plane (or just use the parity plane intact as another bit, then use one pad of broken core to repair the other, less damaged pad of broken core). Any thoughts out there on core repair? It's 1968 DEC core with, AFAIK a seperate sense and inhibit wire, which is both good and bad - good because the cores are larger than three-wire core, bad because I'd have to thread up, down and two diagonals. Of course, I could always sell the broken plane to a collector and use the money to fund part of this working stack. So many options. In terms of time spent, it's cheaper for me to work a few hours and earn the money that the core pirate wants; in terms of lessons learned, repairing a 30-year- old core stack would be a big thrill, *if* it worked. Thanks, -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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Q-Bus and Unibus to ATA info

by emu＠ecubics.com

Hi, -----Original Message----- From: Clint Wolff <clintw(a)colorado.cirrus.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 19, 1999 12:04 PM Subject: Re: Q-Bus and Unibus to ATA info >On the other hand, I have been pondering the development of a ATA >drive controller that emulates MSCP (and possibly TMSCP). I'm sitting on the layout of one ;-)) Problem is, you pay appr 100$ license fee for MSCP, and another 100$ for TMSCP. cheers, emanuel

27 years, 3 months

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Program Challenge (was Re: z80 timing... 6502 timing)

by CLASSICCMP＠trailing-edge.COM

>This is a valid viewpoint, though I think, ultimately, the question to be >answered pivots around which processor was potentially the most efficient of >all its resources, including time. However, just the raw speed got a lot of >discussion. In 1983, the 4MHz 6502 was "old hat" and the 8MHz Z-80H was >readily available. However, AFAIK the peripherals for the Z-80H were not, >and, in fact, I didn't ever see them. Somebody said they were out there at >some point, but I've never seen them offered for sale. Of course, in the "real world", there are many other considerations to systems design other than processor speed and the "my CPU can beat up your CPU" arguments that are familiar to us from our schoolyard days (and seem to continue interminably here.) This is, for example, why the number of 8051-descended CPU's that have been shipped in the past 20 years is in the billions. (OK, very low billions, but it's there.) (1 billion == 10**9, to not confuse the folks who were educated outside the US of A.) -- 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

27 years, 3 months

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Ancient disk controllers

by edick＠idcomm.com

It has to be close to the 1000 because of thee chipset used. However, the chipset deals with the drive-side of the controller, and not at all with the host interface. Consequently, the DAVONG folks, whose documentation for this baby is lying, even as I type, in my lap, accompanied by the four 360K! diskettes, did not see fit to describe this product in much detail in their user manual or installation guide. They didn't even tell you much about the hardware with which you presumably bought this baby. The usual assumptions were made, i.e. that you bought the system interface (which uses a SCSI-type 50-contact connector, hence the conclusion that it was SCSI, which it isn't) so they didn't include the signal definitions for the cables. The odd thing about the box is that there are numerous connectors. There's a power connector, a DA-15, an external drive connector on a DB-25, a drive control cable connector which is a DC-37, and one of those common 50-pin SCSI-1 connectors seldom seen on SCSI equipment except in pairs. There's no ID switch for the controller. Why they'd provide power from one powered box to another isn't clear. That's how it is though. It's likely from a functional standpoint that the controller works more or less like a WD-1000-series controller of the earliest type, i.e. without the WD1010 chip. These had a different arrangement of the registers, probably just inverted, as I recall, from that of the WD1010-chip type. They use a varactor-tuned VCO, just like the WD1000's and again unlike the smaller board with the WD1010 chip. The fact they use the Signetics microcontroller does suggest that these would be similar to the WD1000, but the WD1000 used an 8X300, which maxxed out at 4 MHz while the newer and "improved" 8X305 was called that because it had a few more instructions and features, and operated at 5 MHz. For now, that's all I've got about this DAVONG controller. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 17, 1999 7:41 PM Subject: Re: Ancient disk controllers >> Connector J2 and J1 are together on one side of the long end (J1 is 34-pins >> with half of them grounds, J2 is 20 pins with pins 2, 4, 6, 8, 12, 16 and 20 >> grounded). J3, J4 and J5 are in line on a short end, 20 pins each, similar >> ground pattern to J2. J2 through J5 appear to have connections to a Motorola >> AM26LS32 and a TI AM26LS31 which I take to be some sort of analog chip. > >Those are almost certainly ST506-like data connectors (for up to 4 >drives). The 26LS31 and 26LS32 are differential line drivers/receivers >which can be used for these signals. > >> The final connector, J6 is 50 pins. >> >> J1 appears to be the control cable for an ST506 drive, J2-J5 appear to be >> data cables for talking to four drives. The interesting chips on the board >> include a N8X305N processor, some N82S181N ROMs, an N8X371N with leads going >> right to the 50-pin connector, and five socketed WDC parts copyrighted in 1980: > >Which pins are used on the 50 pin connector? Could it be pinned out as a >SCSI port. Or is it possibly some custom host interface? For example I >have here the data sheet for the WD1001 controller. It uses essentially >the chipset you mentioned. It has a 50 pin host connector, but it sure >ain't SCSI. > >> WD1100V-03, WD1100V-01, WD1100V-04, WD1100V-05 and WD1100V-12. There is a > >I have data sheets for those chips... > >-03 : Adress mark detector >-01 : Serial/Parallel converter >-04 : CRC generator/checker >-05 : Parallel-serial converter >-12 : Improved MFM generator. > >> crystal at 20Mhz in the analog section of the board and an 8Mhz crystal by > >20MHz/4 = 5MHz = standard ST506 data rate. >8MHz is a common enough clock for the 8x300 series of CPUs as well. > >> the processor. In the middle of the board are three vias that are labelled >> as if they are configuration pads, in an inverted-L, labelled "1", "2" and >> "3", with a "W" above them, > >What bothers me, if this _is_ a SCSI controller is that there seems to be >no way of setting the device address. > >My guess is that it's a sort-of WD1001 clone. > >-tony >

27 years, 3 months

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Ancient disk controllers

by edick＠idcomm.com

It's like I wrote a few days ago. There was a bit of confusion about what was what. Several different forces at WD were shuffling for turf, apparently, and the prize, in this case, was the 1000 designation vs the 1001. They had data sheets about a 1000-08 controller but that never made the price list. I have several of the OLD (meaning with the 8X300 + WD1100 chipset) tuned for handling ST506 drives, but none for 8", though I tried to order them through distribution. Western send me several versions of the small board with the 1010, 1014, and 1015 chips as samples, but I couldn't get any of their offering for the 8" drives. I didn't need them, so it didn't really matter. I don't know how far back you remember, but the 8T31 is what they called an interface vector, in the 8X300 doc's, and what it really is, essentially, is a 74373 with built-in decode logic. It can work in either direction so you can use it in both input and output applications. The part is described in the OSBORNE series on microprocessors, in case anyone is interested. The 8X300 is a true RISC. it has 8 instructions and, on the original version, each one took 300 ns. on the version which was current in 1980, it was customarily used with an 8MHz clock which meant each instruction took 250 ns, and in 1981 they trimmed it down to 200 ns with their 8X305. These processors showed up in lots of tape controllers and the like, perhaps an occasional SMD, and at least one LAN application, though I don't know what the protocol was.

27 years, 3 months

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Convergent Technologies System

by patd＠csis.on.ca

Hello: I recently acquired a Convergent Technologies system model CG-1000 miniframe system. Tried hooking up a dumb terminal with no luck. The system appears to be trying to boot from the hard disk but my guess is that the operating system has been deleted :(. Does anyone have any technical information on this system? I gather from searching the web that this system ran a flavour of Unix (RTOS?). Any and all info appreciated. Thanks. Here's some system specs for the curious: 68010 10 MHZ cpu 2 Meg ram 2 - ST251 hard disks Archive Corporation tape backup 5 1/4" floppy drive 2 - RS232 ports 1 - RS422A port 1 Parallel port Front panel says "Motorola Information Systems 6350" Regards Pat Del Vecchio

27 years, 3 months

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Q-Bus and Unibus to ATA info

by clintw＠colorado.cirrus.com

I have been using a CMD technology (http://www.cmd.com) CQD-2xx/TM SCSI <--> QBUS controller in my microvax II, and have been quite happy with it. It emulates MSCP and TMSCP, so no additional drivers are required. Unfortunately, at $800, it is about $800 more than I paid for the computer (sigh). The only down side is, Ultrix 3.1 won't work with a drive with more than 1.2Gb or so, but with some partition magic it works just fine. Also it will talk to my Archive Python DAT tape drive. On the other hand, I have been pondering the development of a ATA drive controller that emulates MSCP (and possibly TMSCP). There is a DEC document that describes MSCP (I don't have the part number handy). Does anyone have a copy they would give/sell/load to me? Thanks, clint > > I don't know if anyone noticed a USENET posting from the Ukraine about a DEC > Hobbyist site. It has pictures AND a bunch of files about connecting ATA > harddrives to a Unibus or Q-Bus system. I was interested in the idea of > using modern HD's so I ftp'd the data and have put it on my FTP site (the > one in Ukraine is, not surprisingly, painfully slow to respond) > > ftp://digital.dp.ua/DEC/ Original site > > ftp://zane.brouhaha.com/pub/dsu/ <- ATA files from original site > ftp://zane.brouhaha.com/pub/dsu.tar <- tar of above files > > It looks interesting, but it also looks like it will take someone a lot > better with the Hardware side of things than I am to make use of this info. > >From briefly looking at the Q-Bus adapter, it looks as if the chips are all > Soviet, which would probably make this more than a little difficult to use. > > Zane >

27 years, 3 months

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z80 timing... 6502 timing

by edick＠idcomm.com

It's true that may be more interesting when you have different vehicles, but if you're trying to determine which of two is faster, don't you focus on those two? Having lots of variations in the hardware only tends to muddy the water. Dick -----Original Message----- From: Hans Franke <Hans.Franke(a)mch20.sbs.de> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 19, 1999 8:57 AM Subject: Re: z80 timing... 6502 timing > >> If you really want to see a drivers only contest, watch IROC racing (was >> just on ESPN this afternoon) - a dozen identical cars, and in 40 laps, the >> pack spread out to a few car lengths. The winner was a Pontiac. So was >> the loser, and every other car in the race. I think that it is more fun to >> watch an event where the vehicles differ. > >> We really need two sections of the whole competition - one section with >> fixed platforms, and one section permitting custom hardware. > >Sounds like Formula 1 and Formula Volkswagen (Back in the 70's a >very popular over her - all cars based on VW Beetle). > >Gruss >H. > >-- >Stimm gegen SPAM: http://www.politik-digital.de/spam/de/ >Vote against SPAM: http://www.politik-digital.de/spam/en/ >Votez contre le SPAM: http://www.politik-digital.de/spam/fr/ >Ich denke, also bin ich, also gut >HRK

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by CLASSICCMP＠trailing-edge.COM

>> >> And i'd probably try to locate Lassiter and see if my some miracle he >> >> could repair the board, etc. >> >> >I don't get the reference. >Neither do I, and I'm the one who wrote it... >> I'm not sure I do, either. Maybe he means Charles Lasner, a frequent >> contributor to alt.sys.pdp8 (aka PDP8-LOVERS) up until a few years ago? >Bingo, Thats who I meant. Is Charles still with us? I haven't heard a peep from him since the mid-(Lasnerian)-90's. (Bonus points to anyone out there who was reading alt.folklore.urban back when "Lasnerian" was coined!) -- 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

27 years, 3 months

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z80 timing... 6502 timing

by allisonp＠world.std.com

<> processor. The more rudimentary the processor, the more points you get. <> I choose the 4004. < <You have a _home micro_ based on a 4004? What the heck is it? TMS1000 chip. Allison

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by CLASSICCMP＠trailing-edge.COM

>> Well, I didnt say that I would pay $100... Or that it was a great price. >> But it might be a fair price. >> >> And i'd probably try to locate Lassiter and see if my some miracle he >> could repair the board, etc. >I don't get the reference. I'm not sure I do, either. Maybe he means Charles Lasner, a frequent contributor to alt.sys.pdp8 (aka PDP8-LOVERS) up until a few years ago? >> But, thats just me. To me, having a PDP8/e is the ultimate dream machine. >> That, and having the room to store a PDP8/e... >A PDP-8/e isn't all that large. Some of the peripherals can cause a >space problem... Even the disk drives are rather small - a fully configured system with multiple RK05's, DECtapes, a few ASR33's, and one of the fixed head disks weighs well under a half-ton, making it a "small" system by the standards of many :-). -- 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

27 years, 3 months

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z80 timing... 6502 timing

by edick＠idcomm.com

Maybe we're talking about two different things, Sam. I thought we were going to put forth a specification for participants to code for whichever processor they wanted or both, just to see which one came out fastest, smallest, or whatever...est. You were the one who mentioned the graphics so one could see what was going on. What I had in mind was a computation, e.g "compute the product of three M x N x L matrices, where M, N, and L are <127, containing prime decimal numbers of not more than 511 and not fewer than 256 digits each". An environment has to be selected for a task like this. You know what I mean. There has got to be some limit on how much a process is helped or hindered by the environment. Dick -----Original Message----- From: Sellam Ismail <dastar(a)ncal.verio.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 17, 1999 4:15 PM Subject: Re: z80 timing... 6502 timing >On Sat, 17 Apr 1999, Richard Erlacher wrote: > >> Let's not start throwing up our respective hands in disgust! Nothing's been >> attempted yet. In fact, nothing's been suggested yet except a couple of >> things which at first inspection didn't seem like they'd work. Now, Hans >> Franke suggested something like a KIM-1. There's no reason one couldn't >> code for something LIKE a KIM-1, even the guys working the Z-80 side, but > >You want people to have to learn 6502 in order to participate in this? >So, I've never touched a Z80, but conversely you'd want me to have the >added burden of having to learn Z80 assembler if we chose to do this on >the Z80? > >I think part of the idea is to implement this exercise on different >processors so that we can all collectively learn how the code to perform >the same algorithm works on the many different varieties. > >> it's inappropriate to choose. If one wants the hardware, it should be the >> SAME hardware throughout the exercise, though. That's why I was suggesting >> a simulator. All that's really needed is a run to see if it actually will > >Ok, Richard. You go off and write this simulator, and design the board to >run it. Then when you're all done with this masterpiece, the rest of us >will have long been done with this little mental challenge and talking >about something more contemporary, like how two years prior the world >did not in fact end on the January 1, 2000. > >> execute and end up with the desired result when code is submitted to the >> hardware. A simulator would be adequate so long as it was trusted to give >> honest timing results. That way, nobody would have to risk burning his >> fingers. > >I think counting clock cycles would be a lot simpler, but that's just me, >always trying to find the sensible solution. > >Sellam Alternate e-mail: dastar(a)siconic.com >--------------------------------------------------------------------------- --- >Don't rub the lamp if you don't want the genie to come out. > > Coming this October 2-3: Vintage Computer Festival 3.0! > See http://www.vintage.org/vcf for details! > [Last web site update: 04/03/99] >

27 years, 3 months

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IBM Optical drive questions

by roblwill＠usaor.net

Hello... I'm getting a couple of IBM optical drives (one internal, one external).

27 years, 3 months

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Lassiter?

by af-list＠lafleur.wfi-inc.com

I assumed he meant John Lassiter of UNIX fame... Do I win the prize? Aaron

27 years, 3 months

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z80 timing... 6502 timing

by edick＠idcomm.com

I want to distance myself from the majority of this nonsense. Building a simple computer with a processor, a ROM, a full compliment of RAM, and a serial console interface is a 10-minute design and a 90-minute fabrication task. If it's designed to fit already existing firmware/software, it's even more or less practical to fit it into that firmware or software's understanding of what the hardware is that fits with it. That means that an operating system might be straighforward to accomplish in a day or two if there's software in the form of a decent monitor or OS to support it. HOWEVER, since there's little hardware support commonly applicable to both of the subject processors, let alone for a number of others, It's silly to consider anything but the simplest of hardware for a real-world implementation. I'm sure most people in any way familiar with the things we had to do back in the '70's will agree, that, from a hardware standpoint, building a single-board system with 64K SRAM, Whatever size of EPROM you like, overlapping it and disabled when copied into RAM, and a serial port is a no-brainer, requiring , as I previously said, about 90 minutes to wire-wrap. It might take longer if you have to find the parts. If you use a WD FDD/HDD card, it will take another 15 minutes to wire up the cable interface. If, however, you use just a WD1770 or 72 you have a floppy drive as well. For the Z-80,that means you have CP/M. I don't know what's comparable for 6502 development. If you simply stop after the serial console interface, say,a 16C450 off an obsolete but otherwise healthy PC serial board, you've got enough to run a decent debug monitor. I have a couple for the 6502, though I was wanting to incorporate the assembly/disassembly functions as well. That hasn't happened yet, and until I'm properly motivated, probably won't. Now I can't imagine why a graphics display, or anything so inane as that could creep into the consciousness of an otherwise perfectly sane person wishing to deal with one of life's fundamental mysteries, i.e. "which is really faster, the XXXX or the YYYY?" Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 17, 1999 7:40 PM Subject: Re: z80 timing... 6502 timing >> Well, while you're at it, why not add a hard drive, > >1 or 2 chips for a SCSI interface... > >> a graphics accelerator, > >More nasty, at least if you want to keep it 'classic'. If I'm allowed >bit-serial (like the MG1), perhaps a couple of dozen TTL chips at most. > >> a scanner, > >See above for a SCSI port > >> an ethernet adaptor, > >Oh, 3 or 4 chips... > >> a pencil sharpener, > >PIA chip + relay driver + relay to control sharpener motor. > >> and a juicer attachment? > >Ditto. > >> >> Jesus Christ! Can't anything be simple for you, Richard? This is a > >You call that _complicated_ :-) :-)... > >-tony >

27 years, 3 months

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Seeking docs: HP 1000-F minicomputer

by jimw＠agora.rdrop.com

'nuff said? I saved a pair of these critters at the Paxotn auction, now need some docs so I can figure out exactly what I'm dealing with here. -jim --- jimw(a)computergarage.org The Computer Garage - http://www.computergarage.org Computer Garage Fax - (503) 646-0174 >>> Coming soon to www.computergarage.org - the CBBS/NW on-line archives >>> Coming to VCF III (2-3 October 1999) - CBBS/NW live!

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

--- Lawrence LeMay <lemay(a)cs.umn.edu> wrote: > Well, I didnt say that I would pay $100... Or that it was a great price. > But it might be a fair price. > > And i'd probably try to locate Lassiter and see if my some miracle he > could repair the board, etc. I don't get the reference. > But, thats just me. To me, having a PDP8/e is the ultimate dream machine. > That, and having the room to store a PDP8/e... A PDP-8/e isn't all that large. Some of the peripherals can cause a space problem... -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

--- Marvin <marvin(a)rain.org> wrote: > > The only real measure I have seen is on ebay, although others can talk about > what goes on in the newsgroups. The last PDP-8i core stack ended at $76.00 > with 14 bids and the reserve was not met. The URL is: > > http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=91272199 > That's me. I had the high bid. The reserve was $100. The seller is willing to sell to me first if I pay the reserve amount. I personally was not unhappy when the price was around $50. I didn't _really_ mind $76, but at $100, I'm forced to consider it hard. I mean, I already *have* working core, several stacks in working machines. I don't _need_ this, thus the debate. Thanks, -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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How to read recalcitrant floppies?

by jfoust＠threedee.com

At 11:52 AM 4/17/99 -0700, Ethan Dicks wrote: >I am attempting to back up some floppies from a project I did a few years ago. >The sets of 3.5" 1.44Mb IBM floppies have been stored in a box, in a cool and >dry room. Out of one set of 12 and one set of 15 disks, I have four disks >that have read errors that DOS won't get past, bad sectors and the like. > >Are there any tools to go divining on DOS floppies that work better than >an endless succession of "R"etries? Try several different drives on different machines. Drives can be out of alignment with respect to each other, and this includes the machine that wrote the disk as well as the machines that read them today. Try reading them on other types of machines, like Macs or Amigas with proper DOS-reading abilities. Another good trick is to hold the disk between your thumb and first finger, then whack each edge on the table-top. Also, get out the can of compressed air to clean out each drive before you try this, and open the shutter on each disk and blow them out, too. - John

27 years, 3 months

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How to read recalcitrant floppies?

by ethan_dicks＠yahoo.com

--- John Foust <jfoust(a)threedee.com> wrote: > At 11:52 AM 4/17/99 -0700, Ethan Dicks wrote: > >I am attempting to back up some floppies from a project I did a few years > >ago. > > Try several different drives on different machines. Done. Used a *new* drive in case my regular drive was dirty, too. > Try reading them on other types of machines, like Macs or Amigas with > proper DOS-reading abilities. That was my next trick. The Amiga reads disks strangely (one track at a time in MFM mode, then converts MFM to binary data by using a portion of the graphics hardware to run a miniterm transformation on the buffer; it uses a 4096-bit shift register in the sound chip to slurp up the track in the first place, the major reason why C= sold 1/2-speed high-density drives that work on Amigas going back to 1985 with no hardware modifications). I'll try the Amiga route this week. > Another good trick is to hold the disk between your thumb and first finger, > then whack each edge on the table-top. I've done that. My question is, how does that work? > Also, get out the can of compressed air to clean out each drive before you > try this, and open the shutter on each disk and blow them out, too. I typically blow gently on the open shutter, being *very* careful to keep the airstream dry. I am not blessed with a collection of canned air. Thanks for the tips, -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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FA: heads up; OSI Challenger 1P

by adavie＠mad.scientist.com

This is sort of a heads-up. Even though I am the actual "seller", I'm really putting this item up for a close friend. I'd buy it myself if I could, but I'm in an anti-aquisition mode myself. It's an OSI Challenger 1P computer + documentation http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=93182204 There are some nice piccies even if you're not interested in bidding. HI to all :) A

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by ethan_dicks＠yahoo.com

When I mentioned the chance to buy a 4kW stack for the PDP-8/i for $100... --- Lawrence LeMay <lemay(a)cs.umn.edu> responded: > Actually, that's probably a reasonable price. Foo! > Core memory boards, probably non-working, have been going for a high price. I got sniped for a PDP-11 double-core stack this weekend, backplane included, that went for $38, no reserve. > Age and a nice visible setup increase the price. The core stack for a PDP-8(i|L) is older than much of what's on the market, but none of the good stuff is visible at all on it. > Now, I havent seen the memory in question. but the pdp8/e core > memory i've seen is all covered by a clear plastic shield. This > increases its value as a display piece, as you can easily see > all the core, and its all protected. It's hard to describe the arrangement, but the core plane in question here is a block with two edge-connectors on either side, "dual-height" as they say, but it's much thicker - let's try bad ASCII art to illustrate... ######## ######## xxxxxxxxxxxxxxxxxx == ######## ######## ######## ######## ######## ######## core planes paddle-boards with wire harness The outside of the core plane part is covered in a "diode matrix", with a wad of twisted-pair wires that go off to paddle-boards, one for the sense bits, one for the inhibit bits. The address lines come up the diode boards, the data comes up and down the paddle-boards. There are several PCBs with core in the core stack, 4-bits per layer with an optional parity layer that has one pad of bits and three pads of core-less X-Y wires. None of this is visible when the plane is assembled, and it's soldered together with lines of wires going up and down the planes. > Of course, in order to use the core on a pdp8/? you would need > a couple of support boards in addition to the core plane board > itself. I would say that just the core plane, being of a nice > size, and being very good 'visually' to display, and somewhat > because its a PDP8 series board (nostalgia value), that its > probably worth $100 all by itself. If it comes with the 2 support > boards and the top connector things at that price, then i'd say > its a bargain. You are thinking of newer hardware. The pre-OMNIBUS 8's have a wad of individual, single-height cards that contain the sense-amps and the inhibit drivers. I have a pile of them from an -8/L that someone else had already begun to strip for parts before I bought it (it also happens to contain the only DEC lock that does *not* use the XX2247 key). I'm not worried about the analog stuff... I need the core. Of course, as Allison pointed out, I could always stick in a lump of battery- backed static RAM. I was contemplating building a wiring harness to adapt an RX8E on the back of either an -8/L (which has 8kW of core out of 12kW in an expansion cabinet) or on the -8/i. I would use berg connector pins to stick the wires on the back side of the backplane (to avoid soldering, of course; but worst case, I just wire-wrap on a connector or two and use sheilded ribbon to move the signals around. The joys of restoration in a market of scarcity. :-P -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

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How scarce (valuable) is core for the PDP-8?

by jlwest＠tseinc.com

In my limited experience with the PDP-8E, memory seems very difficult to come by. I'd give my eye teeth for a 32k semiconductor board, but both semiconductor and core seems to be nowhere. Jay West -----Original Message----- From: Ethan Dicks <ethan_dicks(a)yahoo.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 19, 1999 7:05 AM Subject: How scarce (valuable) is core for the PDP-8? > >I have a chance to buy a 4kW core stack for the PDP-8/i (-8/L). It's >more than I want to pay, $100. My question is, what are these things >going for these days? I don't really *need* it. The guy selling it >has more core than this that he saved from a "recycler", but he's in >it for the money, not out of a love for classic machines. Most of his >memory, he sells to people who want something to stick on the shelf and >"ooh" and "aah" at. :-( > >So... for those people who have been trying to get core over the past year >or two, what's it costing? I'm trying to decide if I want to grab this >stack to put into my -8/i and bring it up to 8kW, an entirely optional >project (I have all the other parts I would need for the upgrade from a >PDP-8/L that I got in 1982 that was sold as parts-only, bad core, and most >of the I/O and part of the CPU missing). > >I think he's charging too much, but maybe I'm disconnected with the >current pricing. I do know that if I pass on it, there are several >other people who are waiting for this exact piece, so it'll be sold >one way or the other when I answer him. > >OTOH, I do have a broken (20-30 fractured cores) -8/L stack that I've >contemplated repairing. It's a parity stack, so I can scavenge wire >and cores from the parity plane (or just use the parity plane intact >as another bit, then use one pad of broken core to repair the other, >less damaged pad of broken core). Any thoughts out there on core repair? >It's 1968 DEC core with, AFAIK a seperate sense and inhibit wire, which >is both good and bad - good because the cores are larger than three-wire >core, bad because I'd have to thread up, down and two diagonals. > >Of course, I could always sell the broken plane to a collector and use >the money to fund part of this working stack. So many options. In terms >of time spent, it's cheaper for me to work a few hours and earn the money >that the core pirate wants; in terms of lessons learned, repairing a 30-year- >old core stack would be a big thrill, *if* it worked. > >Thanks, > >-ethan > > >_________________________________________________________ >Do You Yahoo!? >Get your free @yahoo.com address at http://mail.yahoo.com > >

27 years, 3 months

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Amiga 2000HD Hard disk

by gregorym＠cadvision.com

I'm not sure about the problem you're having with HDToolbox, but what type of HD controller is in your 2000HD? I remember having problems similar to what you're experiencing (old Mac SCSI drive not recognized by OS) when I was using a 2090a in my 2000. When I switched to a 2091, I had no further problems. I think the 2091 was standard in the 2000HD, but it might be worth checking to see if someone has swapped in an old controller... Just a thought. Good luck. Mark. ---------------------------------------------------- Amiga / Apple / NeXT / PDP-11 / PS/2 Computing happily on the trailing edge of technology ---------------------------------------------------- At 07:25 PM 4/17/99 -0400, you wrote: > >Well, I know about HDToolbox, but there's one problem. > >When I try to run HDToolbox, it always says "Driver not installed" in the >box that is supposed to contain drive information. The HDSetup program >will get to the point where it is supposed to start formatting & >partitioning the drive, then just drops back to WorkBench with no >messages. > >Any ideas for this one? > >Thanks, >Kevin >

27 years, 3 months

4
3
0 0

Dumb OS question

by mbg＠world.std.com

>Did something fall into place here for me? >Does the "RT" in RT-11 happen to stand for Real Time? It sure does... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

27 years, 3 months

1
0
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Ancient disk controllers

by edick＠idcomm.com

The mode in which the Shugart SA1400 controllers, after which some of XEBEC's controllers were patterned, was this ultra-simple model. That may not have been the only mode, but I've got an 8" drive controller which seems to work in this way, as it also has no device address switch. I've never found the identifying logo or whatever, but the S-100 adapter I got with this setup has a PROM marked "SA1400." I've also read about this single-target-single initiator mode in the early papers we used in establishing the SCSI-I standard back in the mid-1980's. ( I had the "privilege" of sitting through a number of the standards committee meetings on behalf of my employer back then) Clearly, SOME makers had used this as an operating mode. Multiple disk drives were not that common among small systems back in those days. Dick -----Original Message----- From: Eric Smith <eric(a)brouhaha.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, April 19, 1999 12:07 AM Subject: Re: Ancient disk controllers >> SASI, incidentally was essentially a >> Single-Target-Single-Initiator SCSI so it wouldn't need a device ID switch. > >SASI supported eight targets. Since there was only one initiator and no >disconnects, the initiator didn't need an ID. But the target devices still >needed IDs. > >SCSI-1 added arbitration (for multiple initiators), disconnects (and >reselection), and the 10-byte commands (to support larger devices). I'm not >sure whether SASI supported the message phase; that may also be a SCSI-1 >innovation. > >Usually a SASI host can deal with SCSI disk drives. Sometimes a SCSI >host can deal with SASI targets, as long as it restricts itself to the >SASI commands.

27 years, 3 months

1
0
0 0

Dumb OS question

by allisonp＠world.std.com

<My dumb question: What is a real time operating system? < <Hans Olminkhof Complex question simplified answer. An Operating system (environment) that supports tasks that must keep up with real world events. Timeliness is the key element, either now or within a known time for actions to occur are often part of the specification typical use might be process control where pressure, temperature and ??? are monitored and adjsted to stay withing bounds or require extremely fast reaction to abrupt changes. Things that RTOSs have are interrupt driven events and scheduling of lower priority events for less demanding tasks. RTS-8 (DEC pdp-8) (sources and docs on the 'net) RT-11 (dec PDP-11) Two commercial examples that are well known. CP/M and believe it or not DOS (there are DOS look alikes that are RT) can be as well. Allison

27 years, 3 months

4
3
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Ancient disk controllers

by ethan_dicks＠yahoo.com

--- Pete Turnbull <pete(a)dunnington.u-net.com> wrote: > On Apr 19, 5:58, Eric Smith wrote: > > > Usually a SASI host can deal with SCSI disk drives. Sometimes a SCSI > > host can deal with SASI targets, as long as it restricts itself to the > > SASI commands. > > Some old SCSI hosts can, but most modern ones expect to use messages. I have an ancient driver for monochrome Macs that can be set to old SCSI<->ST-506 bridges like the Adaptec 4000-series or even a couple of SASI controllers. I know I've seen one SASI<->ST-506 bridge - inside the Commodore PET D9060/D9090 hard drives. There's a Tandon TM602S (or TM603S) inside the box, a SASI interface to it, then a Commodore "DOS" board that speaks SASI out one end, IEEE-488 out the other. One of these days, I'll disassemble the ROMs on the D9060 and look for the part that reads the 5Mb/7.5Mb jumper and sets up the drive parameters, then patch in the right numbers for an ST-225 so I can continue to use the thing after my last 5Mb mechanism dies. -ethan _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

27 years, 3 months

1
0
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All this OT stuff...

by JRichardson＠softwright.co.uk

>> I've installed a filter at my end that should dump most, if not all, >> messages with OT: in the subject line. However, the point remains that I >> should not have had to do so in the first place. Hmm, the problem with that being that occasionally OT conversations are interesting/meaningful.... what we need is a filter that only starts dumping OT threads after the first few messages (enough intelligence to never let *any* 'my language is better than yours', gun laws, ABS braking etc etc. conversations through would be great too.... :*) (Hmm, maybe that sounds a bit heavier than it should be... still, it is Monday morning... ;) cheers Jules >

27 years, 3 months

1
0
0 0

Ancient disk controllers

by pete＠dunnington.u-net.com

On Apr 19, 5:58, Eric Smith wrote: > SCSI-1 added arbitration (for multiple initiators), disconnects (and > reselection), and the 10-byte commands (to support larger devices). I'm not > sure whether SASI supported the message phase; that may also be a SCSI-1 > innovation. It didn't; messages first appeared in SCSI-1. > Usually a SASI host can deal with SCSI disk drives. Sometimes a SCSI > host can deal with SASI targets, as long as it restricts itself to the > SASI commands. Some old SCSI hosts can, but most modern ones expect to use messages. -- Pete Peter Turnbull Dept. of Computer Science University of York

27 years, 3 months

1
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The Paxton auction: the aftermath

by jimw＠agora.rdrop.com

For those who have never witnessed the diversity and chaos that has been Paxton's warehouse, pictures taken today during the auction are available at: http://www.computergarage.org/Garage/Paxton/P0??.JPG (where ?? = 06 thru 42) The last few are shots of the collective bootie that the local gang took out. (and yes, its as chaotic as it looks in the pictures!) I'll probably arrange it into a more normal web page in the next few days. For my part, I managed to nab a pair of HP 1000F minicomputers (CPU cabinets only), a Tek 4006 terminal, a DEC TU-81+ tape drive and RA-81 hard drive, a Freiden computerized postage scale, a case of toner kits for DEC LN-03/Scriptwriter printers, a Tektronix Type 230 'Digital Unit', an HP-9000 computer, a DEC MINC-11, and some other assorted goodies. 20 points extra if you can tell us why the unit in this picture: http://www.computergarage.org/Garage/Paxton/P049.JPG had enough significance to rank fairly high on my 'nab' list... More to come... -jim --- jimw(a)computergarage.org The Computer Garage - http://www.computergarage.org Computer Garage Fax - (503) 646-0174

27 years, 3 months

7
13
0 0

Dumb OS question

by jolminkh＠nsw.bigpond.net.au

Tim Shoppa wrote: >Some real-time operating systems can be pressed into service as >general-purpose multi-user OS's. For example, RSX-11M. Others >make quite nice single-user development platforms - for example RT-11. > Did something fall into place here for me? Does the "RT" in RT-11 happen to stand for Real Time? Hans Olminkhof

27 years, 3 months

1
0
0 0

z80 timing... 6502 timing

by edick＠idcomm.com

See my one comment embedded below, plz. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 18, 1999 2:08 PM Subject: Re: z80 timing... 6502 timing >> >> I want to distance myself from the majority of this nonsense. Building a >> simple computer with a processor, a ROM, a full compliment of RAM, and a >> serial console interface is a 10-minute design and a 90-minute fabrication > >Less than that, actually. There's nothing to 'design' IMHO - just stick >the chips on a piece of wire-wrap board and wire-wrap the address and >data buses. While you're doing that, design the address decoder with the >other half of your brain. > >I built a 6809 SBC years ago, and the chip count was pretty minimal. >IIRC: >6809 CPU + 4MHz crystal as the clock >2 off 6264 RAMs (16K RAM total) >2764 EPROM and space for a second one >6551 + MAX232 serial port >9914+75160+75162 GPIB port (that was in the spec, obviously not needed >for a general-purpose machine). >2 off 74LS138 address decoders (one to divide the memory map up into 8K >blocks, the other to subdivide one block for the I/O chips). These days >I'd use a GAL. >A couple of TTL latches and buffers for I/O ports (cofig switches, status >LEDs, etc). > >That was it. Obviously a 6502 could be used with much the same hardware. >A Z80 wouldn't be any worse either. Rockwell made a 65C102 available in the same speed grades as the 65C02. This used a quadrature clock just like the 6809 and worked pretty much like it as well, at least insofar as the timing circuit was concerned. >> Now I can't imagine why a graphics display, or anything so inane as that >> could creep into the consciousness of an otherwise perfectly sane person >> wishing to deal with one of life's fundamental mysteries, i.e. "which is >> really faster, the XXXX or the YYYY?" > >Oh, Sam was suggesting all sorts of complex features and I was pointing >out that most of them weren't that hard to add if you really wanted them. >You don't want them for this challenge IMHO. > >-tony >

27 years, 3 months

1
0
0 0

z80 timing... 6502 timing

by edick＠idcomm.com

That's what y ou have to do when you start with nothing. It's not a new concept. Dick -----Original Message----- From: Mike Ford <mikeford(a)netwiz.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 18, 1999 2:10 PM Subject: Re: z80 timing... 6502 timing >>Sure! Let's have a driving contest to see who can drive the fastest, but >>first we all have to build our own cars. THAT MAKES AN AMAZING AMOUNT OF >>SENSE! > >Shsssh! We're building a race track first. > >

27 years, 3 months

1
0
0 0

z80 timing... 6502 timing

by edick＠idcomm.com

please see the embedded comments below. Dick -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, April 18, 1999 2:05 PM Subject: Re: z80 timing... 6502 timing >> >> If one were going to put an FDC in place, the easiest probably would be the >> WD3765, since it has built in cable-drivers and receivers as well as > >Sure. Or one of the similar, but incompatibly pinned-out UMC disk >controller chips. > >Heck, it wouldn't be hard to add one of the multi-I/O chips from a PC I/O >card and have FDC, 2 serial ports and a printer port. Most of them only >need an 8-bit data bus for those functions. > >> clock/data processing hardware. You connect it directly to the cable, as I >> recall. It otherwise behaves as a uPD765 (i8272). > >Absolutely. The point I was making (not very clearly) is that WD FDC >chips are getting hard to find, but there's no reason not to use an 8272 >(or one of the later chips based on this, but with more things integrated >into the device). > >But if you insist on 'classic' hardware (meaning all the chips you use >were in production at least 10 years ago), you probably won't be allowed >to use some of these more integrated devices. That's exactly the reason I'd prefer to use the WD1002 boards I have around. They handle both the FDC and HDC functions with a minimum of extraneous hardware and would, at least in the case of the Z-80 lead to a productive OS. That's not as likely in the case of the 6502, since there wasn't much of use around for it. Nonetheless, a nonvolatile storage medium of some sort would be convenient, and if I make the board in question home to both processors there'll be no doubt about whether one or the other has more or better resources. I got these boards in 1982. When they were brand new products and, in the case of the 1002's, before they were released commecially. >-tony

27 years, 3 months

1
0
0 0

The Paxton auction: the puzzle

by jimw＠agora.rdrop.com

At 09:18 PM 4/18/99 -0700, you wrote: > >In case anyone's wondering what everything is in the pictures Mr. Willing >took at Paxton's auction, I've identified as many things as I can so that >if anyone ever spots one of these in their travels and wonders if its >worth their while to pick up, they'll at least have an idea what they're >looking at. <snippage> > P023.JPG 17-Apr-1999 22:02 64k > >Damn it! Damn it all to hell! That's the HP 9000/520 Unix workstation >I've been lusting for!! Frank McConnell has the only one I've ever seen. Well then, you're gonna hate me! It followed me home! (or at least, will as soon as I get back to pick it up!) > P024.JPG 17-Apr-1999 22:02 73k > >Tektronix 4001 (or 4002?) storage scope. Well... I thot it was a 4002 as well... It is a 4006-1. It followed me home too! > P044.JPG 17-Apr-1999 22:03 79k > >Is this the HP1000F? I thought you said it was an empty chassis. No, I said I got the CPUs only (as opposed to a complete system). P044.JPG is the rear of the unit, P045.JPG is the front. B^} -jim --- jimw(a)computergarage.org The Computer Garage - http://www.computergarage.org Computer Garage Fax - (503) 646-0174

27 years, 3 months

1
0
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