test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dm561＠torfree.net

-----------Original Message: Date: Thu, 15 Nov 2007 08:32:02 +0000 From: Gordon JC Pearce <gordonjcp at gjcp.net> Subject: Re: Speaking of multiple processors... On Thu, 2007-11-15 at 00:32 -0500, Roy J. Tellason wrote: > Didn't that "Superbrain" computer use a couple of Z80 chips in there? IIRC, > one was the "main" CPU and the other one handled I/O tasks of some sort > (disk?). <snip> It does. I believe one handles disk accesses, while the other does the rest. Once I get mine working, I'll tell you more.<snip> Gordon ----------Reply: Cromemco also had Z80s on their I/O processor boards, and when the later 680x0 CPU boards dropped the Z80 you could still run your Z80 programs on the I/O card. mike

18 years, 5 months

Software for Data I/O 280 programmer?

by derschjo＠msu.edu

I picked up a Data I/O 280 programmer this weekend, without manuals or software. According to Data I/O's webpage, it's no longer supported at all, so they have nothing available for download/purchase/whatever. Anyone have software/manuals/anything for this thing? Thanks as always, Josh

18 years, 5 months

Commodore 65 = $5,000

by spectre＠floodgap.com

Admittedly, I was mulling over it too. This one is not only a real 65, it's apparently in mostly working order (as much as any of the extant 65s are). http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=230190927853 -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- Burglar alarms: For the man who has everything! ----------------------------

18 years, 5 months

How not to fix a classic mac (or: fried logic boards)

by trag＠io.com

> Date: Wed, 14 Nov 2007 16:34:45 -0900 > From: Grant Stockly <grant at stockly.com> > At 03:17 PM 11/14/2007, you wrote: >> > The LAG is labeled "HAL16R8CN 8440 / 342-0251-A" so it does look like >> a >> > custom ("HAL") chip such as what Tony was mentioning. Guess that >> would >>I will try to find all my notes on the Mac+ (but not tonight!). I know I >>never figured out the PAL equations, but I might have something of use. > > There are equations for the PALs on my website: > http://www.stockly.com/forums/showthread.php?t=6 Wow, Grant, that's a really cool website. Where have you been hiding? That is a very cool project. I keep my eyes open for other folks who actually like to tinker with Mac hardware in a circuit board sense and they are few and far between. Even the over-clocking enthusiasts try to avoid soldering at every turn, for the most part. Will you have to rewrite some of the firmware (ROM contents) in order to change the timing of your project and gain the extra speed? Also, have you looked at the Brainstorm accelerator at all--the one which simply added a 16 MHz CPU on top of the original? It had a replacement BUG I think and a small amount of firmware. Jeff Walther

18 years, 5 months

S100 Floppy Controller Question

by ajp166＠bellatlantic.net

> >Subject: Re: S100 Floppy Controller Question > From: M H Stein <dm561 at torfree.net> > Date: Thu, 15 Nov 2007 04:21:34 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > >---------Original Messages: >Date: Tue, 13 Nov 2007 07:48:21 -0500 >From: Allison <ajp166 at bellatlantic.net> >Subject: Re: S100 Floppy Controller Question >> >>Subject: Re: S100 Floppy Controller Question >> From: M H Stein <dm561 at torfree.net> >> Date: Tue, 13 Nov 2007 01:13:48 -0500 >> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > ><snip> >> >>I think you might have misunderstood, Allison; sounds like you thought I was >>talking about replacing an FDC with one other than what the BIOS is configured >>for; obviously that will require mods to the BIOS. > >Ok, then same fdc but sufficiently differnt drive requires new (modified) bios. > >Changes that affect a bios: > > Motor on/motor runs continiously. > > Step rate, head load delay, motor on delay > > Different on disk format (likely with 8 to 5") > > >>What I was responding to was a previous post that suggested replacing an 8" >>drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted >>to mention that this is not the case with a Cromemco 16/64FDC, to which a >>TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive >>are set correctly and it supplies /READY, and that this may also apply to some >>other controllers. Also, if the controller has both 8" and 5 1/4 connectors and >>they are effectively in parallel as they are on the Cromemco, you may not >>even need a 50<>34 pin adapter cable. > >if the drive supplies ready _MAYBE_. If the Drive has the same step rate. > >-------------Reply: > >Well, I should know better than to argue (again ;-) with you of all people, but... > >Since we're talking about 'modern' 5 1/4" HD drives, Motor on and Ready >are jumper selectable on all the drives I've run across, step rates etc. are >faster than the 8" equivalent (except perhaps the PerScis), and with the >same speed and data rate the disk formats are identical, no? the drive used are a factor and many of the later designed systems had what could be described as an adaptive, they have a bios written to accomodate a wider variety of drives. >In any case I'm only specifically talking about my Cromemco system and it >seems to work fine for me. It gives me 1.1 MB on a 5 1/4HD diskette instead >of 360KB and lets me deal with both 5 1/4 and 8" images conveniently in a >single 5 1/4" FH bay box, without the complication of the 24V supply, 50 pin >cable, unreliable old 8" drives etc. To initially read & convert my 8" disks I just >temporarily plugged an external drive w/PS into the unused 50 pin connector. >I haven't tried it yet, but it should also make recreating an 8" image on a PC >easier, and it puts some 5 1/4HD drives & disks to a good use, which otherwise >would end up on the shelf or in the trash since I don't use them on PCs. Cromemco is one such example and much later than Altair/Tarbell. >After installing the drive I happened to run across some old posts in the archives >dealing with this very topic (on a Cromemco); apparently it was easy and worked >fine for some and not for others. I just wanted to add my name to the former >group in case it had relevance to someone else with a Cromemco FDC or >_perhaps_ even with a different make of controller if it's similar, and especially >mention to one of the original posters that it might not be necessary to kludge up a >50<>34 pin adapter cable (which he was reluctant to make) if the two interfaces >on his FDC are handled the same way as on the Cromemco FDC. Same was the case for AmproLB, SB180, and Compupro. Generally most fo the floppies are close to "setup, plug and play". However really old drives for example SA800, SA400 it's fairly easy to get the signals right but things like 40ms step rate (sa400) and 12ms step rate(sa800) have to be driven by software. After about 1981/82 design had fewer problems and 5.25 floppies started to look more alike than different electronically. The gotchas still lurk out there. Allison >mike

18 years, 5 months

Tarbell is making me insane

by jvdg＠sparcpark.net

> I had that a work once it was dust in the drives scaring the disks > after one or two uses. > > Reaaon, PC suck air out of the box, where does it come in? Any ways it > can and through the floppy was one path. True enough. Actually, the first NeXT Cubes had their MO drives fail regularly due to the fan sucking dust in through the drive slot(s). When bringing the machine in for repair, the fan would be reversed to alleviate the problem. Later Cubes were manufactured with the fan blowing in as standard. ,xtG tsooJ

18 years, 5 months

S100 Floppy Controller Question

by dm561＠torfree.net

---------Original Messages: Date: Tue, 13 Nov 2007 07:48:21 -0500 From: Allison <ajp166 at bellatlantic.net> Subject: Re: S100 Floppy Controller Question > >Subject: Re: S100 Floppy Controller Question > From: M H Stein <dm561 at torfree.net> > Date: Tue, 13 Nov 2007 01:13:48 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> <snip> > >I think you might have misunderstood, Allison; sounds like you thought I was >talking about replacing an FDC with one other than what the BIOS is configured >for; obviously that will require mods to the BIOS. Ok, then same fdc but sufficiently differnt drive requires new (modified) bios. Changes that affect a bios: Motor on/motor runs continiously. Step rate, head load delay, motor on delay Different on disk format (likely with 8 to 5") >What I was responding to was a previous post that suggested replacing an 8" >drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted >to mention that this is not the case with a Cromemco 16/64FDC, to which a >TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive >are set correctly and it supplies /READY, and that this may also apply to some >other controllers. Also, if the controller has both 8" and 5 1/4 connectors and >they are effectively in parallel as they are on the Cromemco, you may not >even need a 50<>34 pin adapter cable. if the drive supplies ready _MAYBE_. If the Drive has the same step rate. -------------Reply: Well, I should know better than to argue (again ;-) with you of all people, but... Since we're talking about 'modern' 5 1/4" HD drives, Motor on and Ready are jumper selectable on all the drives I've run across, step rates etc. are faster than the 8" equivalent (except perhaps the PerScis), and with the same speed and data rate the disk formats are identical, no? In any case I'm only specifically talking about my Cromemco system and it seems to work fine for me. It gives me 1.1 MB on a 5 1/4HD diskette instead of 360KB and lets me deal with both 5 1/4 and 8" images conveniently in a single 5 1/4" FH bay box, without the complication of the 24V supply, 50 pin cable, unreliable old 8" drives etc. To initially read & convert my 8" disks I just temporarily plugged an external drive w/PS into the unused 50 pin connector. I haven't tried it yet, but it should also make recreating an 8" image on a PC easier, and it puts some 5 1/4HD drives & disks to a good use, which otherwise would end up on the shelf or in the trash since I don't use them on PCs. After installing the drive I happened to run across some old posts in the archives dealing with this very topic (on a Cromemco); apparently it was easy and worked fine for some and not for others. I just wanted to add my name to the former group in case it had relevance to someone else with a Cromemco FDC or _perhaps_ even with a different make of controller if it's similar, and especially mention to one of the original posters that it might not be necessary to kludge up a 50<>34 pin adapter cable (which he was reluctant to make) if the two interfaces on his FDC are handled the same way as on the Cromemco FDC. mike

18 years, 5 months

Who keeps buying DECTalks?

by silent700＠gmail.com

So I like early speech synthesis. I like DEC stuff. I've got a couple forms of the DECTalk boxes (the portable, the ISA card.) I'd like the DTC-01 unit, the one that sort of looks like a VX2000 terminal. They come up on ebay every other week or so and end up selling for well over $100. Who's buying these things? Are they popular with collectors? Or are they still being used in the disability care industry?

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Gordon JC Pearce <gordonjcp at gjcp.net> > Date: Wed, 14 Nov 2007 08:26:55 +0000 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > >On Tue, 2007-11-13 at 20:28 -0500, Allison wrote: > >> I use a stack (about 200) of written once disks, they have sales >> promo and utility on them and never distributed. Good media >> and easily erased. > >I bought a box of 500 DSDD floppies from a guy on eBay. They appear to >be new. They seem to be pretty good quality too - the cases are a bit >naff and plasticky but they actually work. > >I still don't understand how brand new 1.44M floppies fail after two or >three uses, but the 20-year-old SSDD disks for my Ensoniq Mirage are >still perfectly readable. > >Gordon I had that a work once it was dust in the drives scaring the disks after one or two uses. Reaaon, PC suck air out of the box, where does it come in? Any ways it can and through the floppy was one path. Allison

18 years, 5 months

fS/H: Power Mac 9500 mobo/FD

by Arno_1983＠gmx.de

Hello listmembers, some days ago I stumbled across the remains of a parted-out Power Macintosh 9500 that I have no use for. There are: -3,5" floppy drive (Mitsubishi MF355F-2592MA) -grey plastic mounting sled and 20-conductor ribbon cable for the above -mainboard (P/N: 820-0563-B), bare (no DIMMs, no CPU, heck not even PRAM battery (but with power LED)). Chances are I might go back and snatch case parts incase anybody wants me to; what I remember for sure is that there were no fans left and the back panel was missing too. I couldn't test anything so it's assumed dead and offered for pickup or S&H (inside Europe only). I'm in Germany btw, and I could bring it to the VCFe in Munich next April. Yours sincerely, -- Arno Kletzander Stud. Hilfskraft Informatik Sammlung Erlangen www.iser.uni-erlangen.de Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal f?r Modem und ISDN: http://www.gmx.net/de/go/smartsurfer

18 years, 5 months

can anybody use these tapes?

by rtellason＠verizon.net

In among a whole bunch of audio tapes are these three "Teac CT-500H High Density Magnetic Tape Cassette"s... Instead of the usual tab that you can break out to prevent recording there's a small red bit in one of the holes, which the bit of paper in there refers to as a "write enable plug". Two of the three are still sealed in their original plastic. I don't think even the third one is used at all. Feel free to contact me offlist if you have any use for these... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

18 years, 5 months

How not to fix a classic mac (or: fried logic boards)

by derschjo＠msu.edu

The other day I picked up a Macintosh 512k with a broken monitor for $5 thinking that it'd be a fun project to hack on (yes, another thing to add to my pile of things to hack on, just what I need :)). The power/sweep board had a couple of obviously dead capacitors and a few cracked solder joints, which I fixed up and lo and behold, the screen came back to life and I did a little dance. There was still a bit of jitter in the picture from time to time, and jiggling one of the connectors revealed another dry joint so I powered it down and prepared to fix the other joint. First point of business, I discharged the CRT. To the main chassis. This, as I have now discovered, is not what you are supposed to do to discharge the CRT unless you want to destroy the logic board. I now have a working monitor but a fried logic board; on powerup, the normally short boot tone is long and drawn out, as if the machine were running at a tiny fraction of its normal speed. Which I suppose is actually what's going on. So I killed _something_ on the main PCB, but I'm not sure what. Anyone out there experienced this failure mode? Any obvious things to check? Well, live and learn. At least it wasn't a 128K mac :). Thanks, Josh

18 years, 5 months

TMS 9980

by wmaddox＠pacbell.net

I just won a TI 9980/180M evaluation board on eBay. I was contacted by a losing bidder who apparently is in need of a 9980 processor chip. Does anyone have one for sale, or know an economical source for a single unit? --Bill

18 years, 5 months

Tarbell is making me insane

by compoobah＠valleyimplants.com

On Nov 13, 2007, at 11:50 PM, Chuck wrote: > Very close--I've got 3M's published specs on all of these, if anyone > cares. And 3.5 DSHD media is fairly close to DS2D; the coercivity is > somewhat higher, requiring increased write currents, but not as > drastic as the difference between 5.25" DSDD and DSHD. > It is different enough that after a couple of years DSHD media written on DSDD drives can very easily start to fade- had it happen on some DSHD floppies I wrote on a 800k Mac SE several years ago (diskettes unreadable after about 3 years).

18 years, 5 months

Floppy storage boxes

by mdyori＠verizon.net

can you tell me more about these floppy storage boxes thanks! Martin

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Tue, 13 Nov 2007 11:34:53 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >More to add... > >I know that writing to 3.5" HD disks with the hole covered to make >them look like DD is frowned upon, but maybe it could help determine >why I get errors with the real DD disks. > >While trying to back up my DD disks onto HD hole covered disks I got >an error. Its not the disk because I've tried two and they both fail >at the same spot. Bad write or media, or dirty head scaring disk. >Also, are DD disks the same as Single Sided 3.5" 360/400k >disks? Except for the double sided part? I use a stack (about 200) of written once disks, they have sales promo and utility on them and never distributed. Good media and easily erased. >What are good sources for DD disks TODAY, not NOS disks, but new >disks? Is athana the only place out there making DD disks? > >When copying from drive A to drive B it has an error at the end of >the disk. Is this where a data rate issue would be the worst? Inner tracks are always worst. >A>stat *.* | B>stat *.* > | >RECS BYTS EX D:FILENAME.TYP | RECS BYTS EX D:FILENAME.TYP > 0 0K 1 A:.INT | 64 8K 1 B:ASM.COM > 64 8K 1 A:ASM.COM | 96 12K 1 B:BASIC.COM > 96 12K 1 A:BASIC.COM | 8 1K 1 B:COPY.COM > 8 1K 1 A:COPY.COM | 70 9K 1 B:CPM.COM > 70 9K 1 A:CPM.COM | 38 5K 1 B:DDT.COM > 38 5K 1 A:DDT.COM | 12 2K 1 B:DISKTEST.COM > 12 2K 1 A:DISKTEST.COM | 24 3K 1 B:DUMPDSK.COM > 24 3K 1 A:DUMPDSK.COM | 48 6K 1 B:ED.COM > 48 6K 1 A:ED.COM | 4 1K 1 B:FORMAT.COM > 4 1K 1 A:FORMAT.COM | 56 7K 1 B:PIP.COM > 56 7K 1 A:PIP.COM | 0 0K 1 B:RUN.$$$ > 92 12K 1 A:RUN.COM | 24 3K 1 B:STAT.COM > 24 3K 1 A:STAT.COM | 8 1K 1 B:SYSGEN.COM > 8 1K 1 A:SYSGEN.COM | BYTES REMAINING ON B: 11K >BYTES REMAINING ON A: 0K | > | B> >A> | > >And the error: > >A>PIP B:=*.* > >COPYING - >CPM.COM >SYSGEN.COM >DDT.COM >COPY.COM >PIP.COM >ASM.COM >STAT.COM >ED.COM >FORMAT.COM >DISKTEST.COM >DUMPDSK.COM >BASIC.COM >RUN.COM >DISK WRITE ERROR: =*.* > >A: R/O, SPACE: 0K >B: R/W, SPACE: 11K > >A> > >(can't be too save with my only good boot disk, A:. :) Disk write error... likely just not making it. FYI: 3.5" disks were never meant to run at 125khz. The 720k mode is 250khz and the 1.44mh is 500khz. The read amps just may not work well down that low. Allison > >Grant

18 years, 5 months

cctalk Digest, Vol 51, Issue 36 - DECtalk

by lee＠geekdot.com

> I picked up one of the ISA DECtalkPC's cheap a couple of weeks ago > but I'd like to get one of the externals. They're supported by just > about every accessibililty program. Perhaps it would be possible to make an external to ISA interface using a modern microcontroller. I've found that using ISA cards in small projects is fairly easy and often only needs the data and read/write select lines driven. The address can be fixed to that of the card. Lee.

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Tue, 13 Nov 2007 14:16:59 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > > >> > One little nasty. The 1771 has a basic ability to do data seperation. >> > I havent' looked at a tarbel board in a very long time but I do hope >> > that they didn't do the TRS80 save a buck trick and try to use that >> > internal seperator, it does NOT work. It has zero jitter tolerence. >> >>Strange. I used an unmodified TRS-80 Model 1 EI for years and never had >>any problems with the disk side of things. And that used the internal >>data separateor of the 1771 IIRC. > >If that is the case, why would the Tarbell have so many extra >chips? Also, at the time the tarbell was manufactured, would they >have even known that there was an issue with the 1771's data separation? Because the internal seperator sucked. If the user never had problems it was just dumb luck. Percom (and others) sold thousands of add on data seperator board to all the E1 users that couldn't make it work. >Just wondering why...I'm not trying to second guess anyone. Just >that if the extra ICs weren't required I can't imagine Tarbell using them??? Because they were needed. Even WD advised that it was not adaquate for many cases. Tarbell wasn't stupid, they built protos and tested them and the board they sold worked. Allison >Grant

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: Grant Stockly <grant at stockly.com> > Date: Mon, 12 Nov 2007 15:25:53 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >Wow, a lot to go over here... Rich, if you have any problems with >your drive I might be able to help you after this exercise! : ) > >>Data is comming from the disk, however it's not readable. Possible >>reasons: >> >> NOISE, ground the drive, insure it has good power that the >> system case and it's grounds are common. Also common >> error is long drive cables (stay short for now) and cables >> (and drives) that get near CRTs. > >I'm hooking the 3.5" drive power cable directly to the output of the >7805 on the tarbell, which is getting its power from an 8v switching >power supply. The power is nice and steady at 4.95v. The only thing >I haven't done is made sure the case is grounded. Some drives had >jumpers for that, but mine doesn't. So it could be either way. BZZT!!!! NEVER! The 7805 DOES NOT have the output to support the logic and the Drive power. It might with a modern 3.5" but not any of the 5" older drives. >> Internal: 1771 requires a data seperator to recover clock and >> nice(cleaned up some) read data. The common circuits >> are oneshots and PLLs. Tarbel used oneshots. Generally >> they work well enough if set right. > >The tarbell card I have doesn't have any one shots for data >separation. The read data line goes into a L74 (Dual D Edge >Triggered Flip Flop), then goes into a LS175 (Quad D Type Flip Flop >with Direct Clear). There are two LS161 (Synchronous 4 Bit Binary >Counter) that are hooked up to parts of the LS175. There are is a >XOR gate and two NAND gates. I'm not sure what is going on at the >moment, does it seem like that pile of parts could be implementing a >PLL? I would think a PLL would be more complex than that. I'll at >least make sure all of the edges match up (Read data vs separated >clock and data) It's a oneshot done with counters rather than monostables. Better, stable and predictable. >I hope I find something obvious. I should at least see a difference >between the two tarbell cards (reliably bad vs somewhat bad). I have >a 4FDC Cromemco? It uses a 1771. I might be able to use the tarbell >driver to boot off of that. Is anything known about that card as far >as being better or worse? Make sure the logic osc is really running at the crystal frequency. >> LOGIC: problem with read/wait hardware not working or possible >> data path corruption. > >The two 3.5" drives and the 5.25" drive I have don't do anything with >the ready/disk change line at all. BUT, I know the Sony 3.5" drive >doesn't generate index pulses until the drive speeds up (I think that >is what its doing). That should affect nothing. SA400s (and others) don't generate index if teh media is not spinning (motor off, door open). >With a TEAC 235HF drive it takes 694.053ms for the drive to generate >sector pulses AFTER the drive was given a "Motor Enable" >signal. Even though the head was NOT at track 00, the drive didn't >signal that status until 491.221ms after given a "Motor Enable". So >the drive seemed to spin the motor up, tell the controller it was not >at 0, and then start issuing index pulses. Most systems that used 5.25" drives had a 1second motor delay for the motor to spin up. You dont read as soon as you see index nor does the FDC chip. >That is probably how the 3.5" disk is getting away without a ready >line. The older drives probably generated index pulses regardless of >if the drive is ready or not. These newer drives with more brains >must not make index pulses unless they are ready. Ready is one line I never used nor is it important. Use a jumper to force it true and forget it. >>your shotgunning. I've seen this for 30+ years. Doesn't work, swap >>out the big hairy chip as they must be flaky or why else put it in a >>socket? Rare if ever is that the case. > >On my second kenbak build I had a problem. First I tested all of the >ICs (digital only) but didn't find any problems so I started swapping >them all. About 3 hours after testing it started working, but then >stopped. I found a cold solder joint. Pushing around and bending >the boad "fixed" it. : ) So I fixed the joint and reinstalled all >of the old chips. : ) Probing for a missing signal might have found it faster. Pulling chips risks fatigueing sockets and also ESD to the chips (even TTL). The worst is the motion makes the problem go away only to return days later. >The main reason I swapped the 1771 was because I think I read >somewhere that its a very static sensitive part and of all of them >the most likely to go out... No more so than 8080, z80 or 765. Once in circuit the surrounding stuff further protects it. However ESD can and does kill chips that come to edge connectors. >>FYI: certain brands of sockets of the side wipe style tend to fatigue >>with insertion/removeal and some do it over time leading to failures >>where the chips are 100% good but nothing works and may be flakey >>if wiggled or moved. > >I will replace the sockets with machine pin sockets. Do so as needed. I've had to strip entire NS* MDS boards for that reason. >>DD or HD with tarbel?????? > >The tarbell is treating the 3.5" disk drive as that TM100 tandon SSSD >drive. The data rate recorded to the drive is 8.07us per bit. I'm >getting 123916 bits a second, which doesn't seem to match anything I >remember... That would be single density 5.25" rate and you at 99.1328% of correct which would be 125,000. Less than 1% slow is tolerable. >>HD media is incompatable in every way with older drives and lower >>data rates. > >My drive is a new from sony. I've made formatted and written to HD >disks with the HD hole covered. This same drive reading the same >disks does not always read. I don't know if its the tarbell's fault or not. Disks as in media or drives? Disks as in media is an issue. Better bet is older 720k stuff. FYI HD in this context is meaningless as your running at 1/2 the lowest data rate for those drives. >>Does the read loop test a status bit or hang/wait on read? > >The silly tarbell issues a "IN" to a "wait" port and the tarbell >keeps it in a wait state until the 1771 is good and ready. Kind of >makes debugging hard if the tarbell doesn't decide to stop waiting. ; ) I call that read/hang. It's the only way to go with slow CPUs. If thats the case then your disks test [program should hang if there is no data. > >>can you supply the sector read code? ( should be fairly short) > >The datasheet for the 1771 says "Upon receipt of the Read command, >the head is loaded, the BUSY status bit set, and when an ID field is >encountered that has the correct track number, correct sector number, >and correct CRC, the data field is presnted to the computer." I know that paragraph. It also means the FDC had to find and read those correctly. >Is that the sector read code you are talking about? One of those >first bytes? The data sheet says that the 1771 is capable of reading >the entire track as one big sector. Maybe I should try to make a >routine to do that. I don't know of any other way to get that code >since it isn't part of a normal read. Ah, no the software that manages the FDC. the program segment that does READ IO. > >> >The drive, tarbell, and boot disks were mailed to me from a fellow >> >enthusiast. He made all of the modifications, made the disks, >> >etc. He has tested the setup in an IMSAI (kind of) with my (kit) >> >CPU, a SSM 8080, and a ZPU at 2MHz. >> >>Kind of and exactly are differnt things. > >At least we both have a ZPU and both have one with the 2MHz >switch. So that eliminates the CPU card one shots from the >reliability question. Right? Same bus? Same ram, same Front pannel? >> > 4. With the Altair CPU and the Imsai front panel the Tarbell >> >will boot after you push reset and then push the run switch. >> >>Says the MITS FP is causing some pain. > >FP? FRONT PANNEL. >>The 8t97s worked fine for me. It has 8224? your mod or 8800B? > >That was part of a quote from him. Its not my board. I do have pictures at: >http://www.stockly.com/forums/showthread.php?t=325 > >Its a regular Rev 0 card with some modifications. The biggest >modification is the lack of one shots. It uses an 8224. I imagine >he got this info from a vintage place somewhere because his work >looks very well planned out. Or maybe he just planned it out good! I just ripped up the osc and oneshots plus the drivers and used on of the pad areas to mount the 8224 and wired it in. One problem the 8224 can have is the crystal osc can sometime run at a harmonic of the marked freq or for the 18.384 mhz rock sometimes at a subharmonic. I found it stable but watch for it. >>The only media that should go in that drive is the brown SD/DD floppies. >>If the media was written on a 96tpi drive the noise and jitter _will_ >>be higher due to track width differences. IF the FDC oneshots are >>not quite on that makes a huge differnence. > >I've read that HD (1.44MB 3.5") disks with tape over the HD hole >aren't exactly a DD disk. Something about the track width being >narrower because of the smaller head in an HD drive? BUT, the DD >(720k 3.5") disks were formatted to 40 tracks 18 sectors, 128 bytes a >sector using an HD drive. So the DD disks wouldn't have a wide track >width to begin with. Are there really physical media differences >between DD and HD that would keep a HD disk from being used as a DD >disk when in a HD drive? The HD drive should be able to read the >narrow track written on what it thinks is a DD disk, right? Is the >magnetic material of an HD disk significantly different? the 3.5" all have the same track width. The 5.25" stuff had that wholde thing going on. What the 3.5" had was the media had a different corcivity and there were at least two differnt media and the 1.44 had a harder to write 700 orsted media vs the 720K at 600. > >Most of the information I've read about mixing media is in reference >to DD disks being written in an HD drive and then becoming unreliable >in a DD drive. I've also heard about people who add holes to disks >to make a DD disk an HD disk, which probably works for them better >than my tarbell works for me... : ) Again thats the 5.25" drives. The 3.5" world is generally less muddled for modern drives. (those that likely appeard in PCs). Allison >Thanks! > >Grant

18 years, 5 months

cctalk Digest, Vol 51, Issue 36

by pechter＠gmail.com

> Message: 2 > Date: Sun, 11 Nov 2007 16:18:45 -0600 > From: "Jason T" <silent700 at gmail.com> > Subject: Who keeps buying DECTalks? > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: > <51ea77730711111418j6a375852xea3fcf22f6864744 at mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > So I like early speech synthesis. I like DEC stuff. I've got a > couple forms of the DECTalk boxes (the portable, the ISA card.) I'd > like the DTC-01 unit, the one that sort of looks like a VX2000 > terminal. They come up on ebay every other week or so and end up > selling for well over $100. > > Who's buying these things? Are they popular with collectors? Or are > they still being used in the disability care industry? > Folks like me would love to get some cheap. My wife's blind and from what I've seen the DECtalk is the best sounding of the early Speach synthesis boxes. It's (IIRC) got a pair of 68k chips and some nice software including stuff like an "email mode" which knows how to skip the extraneous header stuff when talking mail messages. I picked up one of the ISA DECtalkPC's cheap a couple of weeks ago but I'd like to get one of the externals. They're supported by just about every accessibililty program. bill -- d|i|g|i|t|a|l had it THEN. Don't you wish you could still buy it now! pechter-at-gmail.com

18 years, 5 months

Slightly OT: Getting parts form Hong Kong

by cclist＠sydex.com

List, I'm starting work on a small hardware project and note that the best deals on items such as PIC microcontrollers are from Chinese dealers. They seem to be reputable and offer items at half the US supplier price. Has anyone had problems with them? My last order from such an HK supplier was a bucketload of white LEDs. Cheap--and they were exactly what the seller represented them as--shipment took less than a week. I couldn't tough the price I paid through normal US dealders (DigiKey, Mouser, etc.). Cheers, Chuck

18 years, 5 months

How not to fix a classic mac (or: fried logic boards)

by trag＠io.com

> Date: Mon, 12 Nov 2007 22:45:09 -0800 > From: Josh Dersch <derschjo at msu.edu> > Subject: How not to fix a classic mac (or: fried logic boards) > The other day I picked up a Macintosh 512k with a broken monitor for $5 > thinking that it'd be a fun project to hack on (yes, another thing to > add to my pile of things to hack on, just what I need :)). > > First point of business, I discharged the CRT. > To the main chassis. This, as I have now discovered, is not what you > are supposed to do to discharge the CRT unless you want to destroy the > logic board. > > Anyone out there experienced this failure mode? Any > obvious things to check? That particular failure is documented in Larry Pina's "Macintosh Repair and Upgrade Secrets" and probably in "The Dead Mac Scrolls" as well. I'd look it up for you, but I don't have my books with me here. It's definitely an IC, but I don't remember which one, nor how rare/common it is. If someone else doesn't jump in with the answer, email me (to remind me when I'm at home) and I'll look it up. Jeff Walther

18 years, 5 months

Do you have oldest-running HP-UX system in the U.S?

by darin.lory＠gmail.com

I thought I would pass this on....I'm sure someone on this list could win this!!! -Darin Do you have the oldest running HP-UX server? If you do, you'll receive a new HP Integrity server as our celebration gift. Register to claim your complimentary limited edition 20thanniversary sweater. If you have the oldest-running HP-UX system in the U.S., you'll receive a new HP Integrity rx2660 server.(2) Your HP-UX server could be more valuable than you think. If it's the oldest HP-UX server still in production, you'll receive a HP Integrity server.(2) Register to enter and receive your complimentary special edition 20th anniversary sweater.(1) https://h30046.www3.hp.com/campaigns/2007/promo/1-43HP8/index.php?key=HPUX&… Register today to see if it's yours and receive: * A limited edition 20th anniversary sweater(1) * A chance to receive(2) an HP Integrity rx2660 server with HP-UX 11i v3 license and HP Care Pack Service * Outstanding trade-in discounts Celebrating 20 Years of HP-UX customer loyalty. Find out if you have the oldest running system https://h30046.www3.hp.com/campaigns/2007/promo/1-43HP8/index.php?key=HPUX&… Technology for better business outcomes. _____________________________________________________________________ 1. Complimentary HP-UX anniversary offer subject to HP terms and conditions. Offer available to all U.S. customers with a valid HP-UX server serial number while supplies last. You must meet HP qualifications. HP may discontinue this offer at anytime. 2. Rules: No purchase necessary. Open only to U.S. entries. Entries must be received by January 15, 2008. HP will determine and select the oldest running system from all valid entries received, based on the oldest running instance of a HP-UX server currently in production. HP reserves the right to disqualify entries for any reason. The oldest running system will be announced in February 2008. (C) 2007 Hewlett-Packard Company. All rights reserved. All product and company names referenced herein are trademarks of their respective owners. THIS DOCUMENT IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY. INFORMATION PROVIDED IN THIS DOCUMENT IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED. This document may be copied provided all text is included and copies contain HP's copyright notice and any other notices provided herein.

18 years, 5 months

"Barn" finds - Victor 9000, Rex Microcomputer and Intersil Development System

by jplist2007＠kiwigeek.com

Hey all; My wife's grandfather started a company that made the first digital meter for propane (and other gaseous) distribution and they're clearing out their old facility (which the family calls the Car Barn, for his collection of vintage Packards now stored there). Couple of goodies, but I'm afraid I'm having trouble finding much on some of them, thought perhaps those out there might be able to help. The first is a Victor 9000 which I found some descriptions of and, thanks to Al, a manual on BitSavers. I'll dig into that one later. The next is a 'Rex Microcomputer System', model REX-1032, "Manufactured by Realistic Controls Corporation of Davenport, Iowa". I'm guessing this is a kit computer that's been put together by this local company, but "Rex Micrcomputer" gets me nothing via google and breaking it down gives me screeds of irrelevancies. The machine has a Z80 microprocessor, although it might have another (ala Rainbow) and I just haven't dug far enough. The last is quite a beasty, weighing plenty thanks to its significantly hefty linear power supply. Intersil Development System, ISB 80DS 3020-120. Got six apparently serial ports on the back with what I think is a console cable hanging out one side. What I like best is the socket mounted in the front plate for reading/writing 24 pin DIP chips. Two 8" drives with diskettes in them, God only knows if they're still good after sitting out for this long. I'll give all of the above a good part of the day to warm back up (20F last night in Iowa and they sat out in my car, the boards are now sufficiently slick with condensation in my office) and see what I get. I have a monitor for the Victor and the Rex (a rather adorable 8" Sanyo TV), we'll see what happens on the Intersil. I'd love to hear from anyone who is famaliar with these, on or off-list, your choice. JP Hindin Iowa

18 years, 5 months

S100 Floppy Controller Question

by ajp166＠bellatlantic.net

> >Subject: Re: S100 Floppy Controller Question > From: M H Stein <dm561 at torfree.net> > Date: Tue, 13 Nov 2007 01:13:48 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > >---------------Original Message: > >Date: Sun, 11 Nov 2007 17:51:09 -0500 >From: Allison <ajp166 at bellatlantic.net> >Subject: Re: S100 Floppy Controller Question >To: cctech at classiccmp.org >Message-ID: <0JRD004G7656LL73 at vms044.mailsrvcs.net> >Content-Type: text/plain; charset=iso-8859-1 > >> >>Subject: Re: S100 Floppy Controller Question >> From: M H Stein <dm561 at torfree.net> >> Date: Sun, 11 Nov 2007 17:33:20 -0500 >> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > ><snip> >>I think Tim's point was that if your controller's smart enough to deal with a >>relatively modern 8" drive like a TM848 it could probably deal equally >>well with a 5.25" HD drive and you could transparently restore an 8" image >>(if you have one) to the 5.25" disk. The controller (and CP/M) would not >>even know that it's a 5.25 instead of an 8"; my Cromemcos certainly don't, >>although a different FDC might well require some mods to the BIOS. > >Different FDC WILL require a different bios. Same for SERIAL IO. > >Allison > >-----------Reply: > >I think you might have misunderstood, Allison; sounds like you thought I was >talking about replacing an FDC with one other than what the BIOS is configured >for; obviously that will require mods to the BIOS. Ok, then same fdc but sufficiently differnt drive requires new (modified) bios. Changes that affect a bios: Motor on/motor runs continiously. Step rate, head load delay, motor on delay Different on disk format (likely with 8 to 5") >What I was responding to was a previous post that suggested replacing an 8" >drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted >to mention that this is not the case with a Cromemco 16/64FDC, to which a >TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive >are set correctly and it supplies /READY, and that this may also apply to some >other controllers. Also, if the controller has both 8" and 5 1/4 connectors and >they are effectively in parallel as they are on the Cromemco, you may not >even need a 50<>34 pin adapter cable. if the drive supplies ready _MAYBE_. If the Drive has the same step rate. >Nevertheless, controllers meant for some of the older, non-'standard' 8" drives >probably will require changes to the BIOS, and likely also hardware mods. BTDT, drive changes ultimately a BIOS and in few cases the mods are small and most not interchangeable. Allison > >mike

18 years, 5 months

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