test-drb

test-drb@ccmp.vtda.org

101090 discussions

New acquisitions (PDP 11/40 DecDataSystem and 11/10)

by wacarder＠earthlink.net

This morning I moved some newly acquired PDP-11 items into my shop. Among the items were a beautiful PDP-11/40 DecDataSystem in a yellow / red color scheme along with a TU10, PC05, and RK05F, another standard PDP-11/40, a PDP-11/10 with a Laboratory Peripheral System, RX01, and TU60 DecCassette unit, and a pieces parts PDP-11/20. Also included in this shipment was an LA36 DecWriter II that has a phone handset modem unit. You can check out some pictures at: http://www.woffordwitch.com/PDP1140-DecDataSystem.asp http://www.woffordwitch.com/PDP1140-FourthOne.asp http://www.woffordwitch.com/PDP1110-2.asp http://www.woffordwitch.com/LPS-11.asp I have not done anything with these items besides move them into my shop. The 11/20 is in pieces in a box, and I have not evaluated the completeness of it yet. I did see the toggle switch front panel, but do not see the plexi that goes with it. I have the CPU box, but some boards are loose in another box. I need to take inventory to see exactly what I have. Ashley Carder http://www.woffordwitch.com

18 years, 5 months

dovebid: Onyx2 Reality Monster (Hazelwood, MO)

by legalize＠xmission.com

<http://www.dovebid.com/assets/display.asp?ItemID=cse2741> -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 5 months

Need HP75 Manual

by silent700＠gmail.com

Hi all - wondering if anyone has a scan of the manual for the HP75 portable computer. If not, I'd like to talk to anyone that has operated theirs with the card reader and can give me some help re: the command syntax? I've finally gotten a power supply for mine (thanks to the big junkpile at VCF!) and I have a whole stack of magstrips and no idea how to read them. I found a page with partial docs that allowed me to catalog a strip, but that's where I'm stuck. Thanks in advance -j -- silent700.blogspot.com Retrocomputing and collecting in the Chicago area: http://chiclassiccomp.org

18 years, 5 months

PDP by the pound

by tponsford＠rnsmte.com

HI All A friend mentioned to me he saw what looked to be some DEC equipment at a local scrap yard. Looking through the scrap I saw a really sad looking rack with some RA81 and 82's. They looked too damaged and too hard to dig out, but as I was leaving, out of the corner of my eye, I spied another "buried" cabinet with 8" floppy drives. Curiosity got the best of me and a closer look the cabinet said KEVEX 1600. The floppies looked to be in good condition so I removed the cover plate and lo and behold, a Qbus 11/03 greeted me! I yanked the third-party qbus chassis out and also the *" drive cabinet, which turned out to be a DSD 210! The scrap yard charged me by the pound, around $20! Cheers Tom Ponsford

18 years, 5 months

Fwd: 1979 CGI on PDP-11/70 w/Tektronix 4014

by legalize＠xmission.com

>From a friend of mine from Project DELTA. Watching Ralph do his thing with the Tektronix terminal is what kept me interested in programming and made me want to study computer graphics. Hi Guys, I finally got around to having some old Super-8 movies converted to QuickTime, and then posted them to YouTube. These show some wireframe computer graphics I developed in high school thanks to project Delta. A bit crude but bear in mind that it's 1979 and I didn't refer to any literature and wrote it all in Basic+2 spaghetti code ;-) Graphics shot directly from Tektronix display (stop-motion used to get animation effect) using high-speed B&W film. Note many of the scenes are stereoscopic: if you have a viewer you'll see the stereoscopic image or if you cross your eyes you will see the image with reverse perspective. http://www.youtube.com/watch?v=ue4Yo_a34XM Music video for Pink Floyd's "Welcome to the Machine". This is primarily pastel on paper, but there is a portion in the middle using printouts from the Tektronix display which I colorized by holding a match under the paper. There's also a shot of a Beehive (?) terminal at the end running a rasterized Game of Life. http://www.youtube.com/watch?v=IAfK1rL9fCw -Ralph -- Ralph Gonzalez ralphgonz at gmail.com -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 5 months

Tarbell is making me insane

by ajp166＠bellatlantic.net

> >Subject: Re: Tarbell is making me insane > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Thu, 15 Nov 2007 20:50:34 +0000 (GMT) > To: cctalk at classiccmp.org > >> >This faster signal might be better for the disk drive? >> >> Potentially. Remember FM floppy recording was passe' by the early >> 80s with every one needed far greater space. It want even a >> consideration buy time PC 3.5" floppies hit the street. > >As I understand it, FM at 125bps has (only) pulse spacings that can occur >in MFM at 250kbps. The latter has some other spacing too, of course, but >the point is that unless you're trying to be awkward, it's impossible to >make a drive that will correctly handle any MFM data at 250kbps that will >not also correctly handle FM data at 125kbps. (About the only way you >could do it is if the drive tries to decode the data back to user bytes >and then re-encodes them onto the disk in a totally different way. I know >of know floppy drive that ever tried something like that!). > >There should be no problem at all in using a 3.5" DD floppy drive with >the FM data stream that uou'd have sent to an SA400. Doesn't completely work that way. If it were bandwidth only maybe. The problem is it's timing and that causes peak shifts that increase with jamming those bits in a more confined space (flux tranistions per inch) and that makes 3.5" track 000 an approximation of SA400L track 41ish. That doesnt' factor the lower S/S+N ratio of 135 tpi against 48TPI. Will it work, I may but if it doesn't work well it may not be broken. Reason is the DD FDCs (both 765 and 1793/2793) have additional hardware to add a timing shift based on pattern written and better feature extraction for read. This is not present on 1771 based boards. Allison >-tony

18 years, 5 months

Speaking of multiple processors...

by ajp166＠bellatlantic.net

> >Subject: Re: Speaking of multiple processors... > From: M H Stein <dm561 at torfree.net> > Date: Thu, 15 Nov 2007 11:29:05 -0500 > To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org> > >-----------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 This is not uncommon. H89 had two, one for the terminal and the other was the processor for the computer. My NS*Horizon had two when I added the Teletek HDC(hard disk) as that has a local z80. When I added a smart FDC of my own design and later smart printer spooler and other IO with local cpu the nuber fo cpus grew. The Compupro system can easily have three, ZPB, Their mux board and any of the hard disk controllers. I have one that has 68000, 8085 and Z80 (maincpu, mux and Disk3). It's something that isn't unusual as it would seem. Allison

18 years, 5 months

BBC coverage: Colossus vs. Modern hardware

by rdawson16＠hotmail.com

> Date: Thu, 15 Nov 2007 19:14:48 -0500 > From: wdonzelli at gmail.com > To: cctalk at classiccmp.org > Subject: Re: BBC coverage: Colossus vs. Modern hardware > > > AFAIK there's no transmission equipment as part of the SZ42 itself though, so > > something would still need to be hooked between that and a giant aerial in > > order to do the transmission; I think it was this bit that Will was interested in. > > No, I am interested in the thing that modulates the bitstream, before > the transmitter. The modem, basically, not the transmitter. > > -- > Will Will, I did some fairly bizarre modem design for a downhole well logging camera, transmitting power and digital video over 5 miles of coax. I can probably answer any modulation questions you may have, or point you to the literature I used in my research and design. Randy _________________________________________________________________ Peek-a-boo FREE Tricks & Treats for You! http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us

18 years, 5 months

Colossus code-breaking again (Jules Richardson)

by mike＠brickfieldspark.org

> Nice article up on the BBC news website about the Cipher Challenge that's > going on today: http://news.bbc.co.uk/1/hi/technology/7094881.stm > ... I've not been involved in that side of things, but it's been > interesting > watching Tony and his crew running around the last few weeks trying to get > everything put together (there was a huge amount to do on the > reception/intercept side of things in particular) > Saw that on BBC 1 news last night, would have liked a bit more info but at least they actually covered it on national news. Do we know how the test went and who gor there first, BBC quoting them at finishing about the same time. Mike.

18 years, 5 months

Heathkit 89 in Seattle

by tosteve＠yahoo.com

Do not contact me, contact Patrick below: ------------------------- I have a heathkit I think H89, not sure how to tell. Should I dump it or is it worth something to someone? If so feel free to contact me. Patrick Seattle WA p_miceli at hotmail.com --------------------------------- Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now.

18 years, 5 months

BBC coverage: Colossus vs. Modern hardware

by rdawson16＠hotmail.com

> Date: Thu, 15 Nov 2007 19:14:48 -0500 > From: wdonzelli at gmail.com > To: cctalk at classiccmp.org > Subject: Re: BBC coverage: Colossus vs. Modern hardware > > > AFAIK there's no transmission equipment as part of the SZ42 itself though, so > > something would still need to be hooked between that and a giant aerial in > > order to do the transmission; I think it was this bit that Will was interested in. > > No, I am interested in the thing that modulates the bitstream, before > the transmitter. The modem, basically, not the transmitter. > > -- > Will Will, I did some fairly bizarre modem design for a downhole well logging camera, transmitting power and digital video over 5 miles of coax. I can probably answer any modulation questions you may have, or point you to the literature I used in my research and design. Randy _________________________________________________________________ Boo!?Scare away worms, viruses and so much more! Try Windows Live OneCare! http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmail…

18 years, 5 months

MIT provides MULTICS source and documentation

by compoobah＠valleyimplants.com

On Nov 15, 2007, at 2:28 PM, Chuck wrote: > How about ATAoAL? ATA over Aldis Lamp? Should be doable... > The standard should include a bridge to either Bongo drums or smoke signals. The smoke could be produced by old tantalums to bring it back on-topic.

18 years, 5 months

Drive sizes (WAS Re: MIT provides MULTICS source and documentation)

by compoobah＠valleyimplants.com

On Nov 15, 2007, at 2:28 PM, Roy wrote: > I mentioned it in here because it came up in conversation with > somebody in the > list a while back and they said something about the 1-2G range of > sizes being > particularly useful for some things, though I can't recall at the > moment > just what those things were offhand. > IRIX 4D1-3.3 seems to not like drives much over 1GB, many VAXstations don't like drives over 1.05GB for VMS, SCSI Apollo/DOMAIN systems don't like drives much over 2GB. I know there's more but can't recall right now. There should probably be a "disk size limits FAQ" somewhere to hold all of this

18 years, 5 months

VAX 11/750 Config and Diagnostics, anyone?

by oldcpu2＠rogerwilco.org

Just wanted to update everyone on the status of the Montpelier, Idaho VAX 11/750 that was rescued last month without much in the way of included modules, except for the Systems Industries 9700 controller...and, to ask for some help. After a little effort, I think I now have the minimum boardset required to fire this baby up. But just to make sure that yours truly, a complete Unibus and big-iron VAX noob, has it figured correctly, I wanted to run my configuration by you guys before I shoot off my right foot (which would, of course, leave me with only a wrong foot). I've now got the following installed in the backplane: <nothing> in CMI slot 1 (still looking for the optional L0001 FPU) L0002 (DPM) in CMI slot 2 L0003 (MIC) in CMI slot 3 L0004 (UBI) in CMI slot 4 L0008 (PCS) in CMI slot 5 L0006 (RDM) in CMI slot 6 (optional, I guess, but came with other boards) <nothing> in CMI slot 7 (I pulled the SI9700 from this slot) <nothing> in CMI slot 8 <nothing> in CMI slot 9 L0016 (CMC2) in CMI slot 10 M8750 (1MB RAM) in 'extended' slots 11-18 (8MB total) M9202 (Unibus 'joiner') in slots 19 and 20 M7485 (DZ11) in Unibus slot 21 <nothing> in Unibus slot 22 <nothing> in Unibus slot 23 <nothing> in Unibus slot 24 <nothing> in Unibus slot 25 <nothing> in Unibus slot 26 <nothing> in Unibus slot 27 M9313 (Unibus Term) in Unibus slot 28 I still don't have any mass storage interfaces (to support my RA81 and/or x2 Fujitsu SuperEagles...still looking for UDA50, Dilog DU256, and/or Emulex UD33), but I was hoping that I have enough modules to start testing the CPU, anyway. I do need to review Ethan's earlier comments about properly jumpering the now empty CMI slot 7, but I'll do that before I power up. Does this look like a reasonable config for now, at least to start testing the CPU? Also... I have successfully cobbled a cable between the onboard TU58 drive (using external power) and a PDP-11/23+. (Yes, I could have used a PC with John Wilson's PUTR, but the PDP was handy...the cable works either way.) I have managed to image the four carts that were part of the rescue. So at least I know that the TU58 is operational. They're probably already 'out there', but for what it's worth, if anyone wants a copy of these images, let me know... BE-J844Q-BE VAX FORTRAN V4.4 BIN TU58 1/2 BE-M873G-BE VAX FORTRAN V4.4 BIN TU58 2/2 BE-CJ51E-BE VAX FORTRAN V4.4 BIN TU58 1/1 [help files, I think] Systems Industries 9900 VAX/VMS Installation Package v4.0 After reading through the various docs found on bitsavers.org and vt100.net/manx it appears that a standard set of TU58 DECtape II carts were included with each system. Several of these carts contained CPU and system diagnostics. I'm hoping someone has a set of these tapes imaged somewhere that I could download and give a try. According to the VAX 11/750 HW Installation and Acceptance manual, the tapes with diagnostics are: Tape 5: - ECKAL - Cache/TB - ECKAX - Cluster Exerciser - ECKAM - Memory Diagnostic Tape 6: - ECSAA - Diagnostic Supervisor - ECCBA - UBI/DW 750 Diagnostic Tape 7: - EVKAA - Hardcore Instructions Tape 8: - EVKAB - Architectural Instructions - EVKAC - Floating-Point Instructions - EVKAD - Compatibility Mode Instructions - EVKAE - Privileged Architectural Instructions Can anyone help me out? Thanks. - Jared

18 years, 5 months

cctalk Digest, Vol 51, Issue 47

by compoobah＠valleyimplants.com

On Nov 15, 2007, at 3:22 AM, Chuck Guizis wrote: >> Which reminds me of a comment I saw somewhere about the possibility >> of having >> a SCSI bus with more than one host adapter on it. Is that even >> possible? Supported on (some? all?) Alphas for clustering.

18 years, 5 months

What is an Epson BM5?

by ard＠p850ug1.demon.co.uk

Can anyone tell me anything about the Epson BM5 floppy drive unit? Perhaps a little description will help. Physcially it's about the size of an Epson TF20 and has one vertically-mounted half-height floppy drive on the front, along with a power LED. On the back are the usual mains connector and switch and a DB25 socket. The unit splits into 3 main sections, PUS, controller and drive The PSU consists of a mains transformer and a PCB cotnaining an STK7561 hybrid chip. It claims to give out 5V at 2A and 12V at 3A. I guess there's nothing to add about that. The controller claims to be a 'Rabbit Board'. The main chips are a Z80A, 24K of SRAM, 8K of EPROM, an 8237 DMA chip and a 7261, which seems to be a _hard_ drive controller. And of course a lot of TTL glue. The DB25 socket is fixed to this board, it's clearly a TTL level parallel intefave, possibly SCSI-like. The drive links to the cotnroller by a pair of ribbon cables, 1 20 way and 1 34 way. I'm seriously suspecting an ST506/ST412 interface -- yes, on a floppy drive. The drive is Hitachi FDD541. The mechancial side looks conventional, a stepper motor postiioned (it desont _seem_ to be servo-trackedm, although I guess it could micro-step). Spindle motor, etc seem normal to, there is a head-load solenoid. The disks are clearly of the normal 5.25" form factor, but I suspect of a much higher coercivity. There's a logic board fixed to the drive, full of ICs I've never heard off, including a 637B01X0P (Microcontroller?), and an ASIC in a PGA opackage). The contorller interface really does look like ST506/412. Anyone got any ideas? What was it used with, what is the host interface? -tony

18 years, 5 months

Commodore 65 = $5,000

by jvdg＠sparcpark.net

> Tony Duell wrote: > >> However, I am saddened by a classic computer that will never be turned on >> again. Computers are not fine art, they are machines that should be run >> (and for that matter, I feel that fine art should be viewed, not stored >> in a vault). > > As much as Tony is a hardware guy, I'm a software guy on the other end > of the spectrum. And yet I wholeheartedly agree with this, to the point > where pretty much all of my hobbyist programming is done on old iron. > It's not enough that I use my old machines; I have to make them jump > through new hoops :-) I agree, in principle, but there are exceptions. I *prefer* a machine to work, but some machines are of such beauty that I wouldn't part with them for the world even if they didn't work. My SGI Crimson Jurassic Classic is one such example. Even if it were just an empty shell, I'd still stick it in my living room as a side table. That monster is just too beautiful not to have on display, and my particular machine has enough of a history attached to it that it makes a historic artefact and a prime conversation piece. ,xtG tsooJ

18 years, 5 months

DDC Fixed Head Disks

by leeib＠sequan.com

I was reading your thread about DDC head-per-track drives. I had a friend around 1980 that had one of these drives which he had obtained as surplus from the US Air Force. It used helium atmosphere around the disks to reduce friction. The disk was 12" in diameter and spun at 33,000 RPM (not a typo), and so it would produce considerable heat from friction if ordinary air were used, at least that's what I heard at the time. It was intended as a substitute for magnetic core (RAM) for mainframes. The disk latency was around 30 microseconds. Because the driving electronics were a lot slower then, the rated random access speed was (as I recall) 50 microseconds. 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: Mon, 12 Nov 2007 00:43:21 -0900 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Allison, thanks a lot for the detailed response! A lot of that info >can be used to help other people too! > >I've written this e-mail from the "bottom up", so some things may >seem out of order in the time line. > >I think that I'm to the point where I've narrowed the problem down to >inside the tarbell card, but I don't think the problem is the >1771. Any further hints are well appreciated. : ) I've seen bad 1771s out of the box (WD was not allways a qualaity house) but I've never seeen one fail in service excluding overvoltage or reverse polairty. 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. >I think we're getting closer! > >> >I can't speak for the exact combination of the Tarbell, but the >> >system has been running all day long with: >> >-16k static card >> >-8k static card >> >-4k static card > >The disks are 24k CP/M 1.4, the 4k is for the monitor. Forgot to say >that... Included on my source disk (which is read by the flaky >tarbell) is a BIOS for 48k CP/M, but I have never had it going long >enough to patch, movcpm, or whatever it is that has to be done to get >the new CP/M onto the disk... Just making sure. >>Ok you have 28k ram. Is the image sized and booting in that? >>If the image is sized for say 32 or 48K it will crash, likely >>as a bounce back to rom monitor. > >See previous response for a description. When it runs, it >runs. When it doesn't...it doesn't : ( The fact that it runs is good. You have a viable image but a systemic problem. >I spent all day long writing my own tarbell driver / monitor program >that would select, reset, seek, read, write, etc. When I tried the >read monitor command for the first time I didn't get an error. I >tried booting CP/M and it worked... Then I swapped to the more >troublesome tarbell card to get errors (I know, stupid) The problem >appears to be within the tarbell card. I can reliably get my tarbell >monitor to report this: > >Reading A Sector >ERROR: Record Not Found! >" 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. Jitter: EXTERNAL: This can come from noise as above. Also drive mechanical issues. 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. LOGIC: problem with read/wait hardware not working or possible data path corruption. > >When I swap to the "better" tarbell, the basic sector read command >passes. (BTW, the reliably bad one above did boot CP/M once and gave >me a few good sectors!!! And I've swapped the 1771 between boards >and the bad stays bad and good stays good!) Basically I use the >monitor to clean the memory, load my program, and then I flip the >reset switch on the Altair. The Altair runs my program which starts >at 0000 and then jumps back into the rom monitor. Here is the >tarbell being good: 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. 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. >" >MON85 Version 1.1 > >Copyright 1979-2006 Dave Dunfield >All rights reserved. > > > F0000 3000 00 > > L > > > >Reading A Sector > >MON85 Version 1.1 > >Copyright 1979-2006 Dave Dunfield >All rights reserved. > > > m2000 >2000 1E 0A 31 00 01 21 00 45 16 33 0E 02 06 04 79 CD ..1..!.E.3....y. >2010 2A 00 15 CA 00 5A 06 00 0C 79 FE 13 DA 0F 00 3E *....Z...y.....> >2020 53 D3 F8 DB FC 0E 01 C3 0C 00 D3 FA CD 41 00 3E S............A.> >2030 88 B0 D3 F8 DB FC B7 F2 41 00 DB FB 77 23 C3 34 ........A...w#.4 >2040 00 DB F8 E6 9D C8 1D C2 02 00 32 80 00 2F D3 FF ..........2../.. >2050 C3 50 00 00 5A 80 04 19 00 02 00 45 80 04 15 01 .P..Z......E.... >2060 01 80 51 00 00 00 00 00 00 00 00 00 00 00 00 00 ..Q............. >2070 00 00 00 00 00 00 00 00 00 00 00 00 00 C3 00 00 ................ >" > >I have to pull the card out to enable the boot rom...guess what, it >boots...but at the moment it is only reading "real" DD media. The HD >media with the tape "works" but BDOS complains about "bad >sectors". This HD disk on another day works just fine. DD or HD with tarbel?????? >I ran one of the programs: >"A>disktest > >TARBELL MINI-FLOPPY DIAGNOSTIC OF 8-1-80 >STANDARD VERSION 1.8 >40 TRACKS 18 SECTORS > >SELECT DRIVE. (A/B/C/D) a >HOW MANY RETRYS? (0-9) 4 >SELECT STEP RATE. (S=40MS,M=20MS,F=12MS) m >FULL TRACK SEEK? (Y/N) y >TO START TEST TYPE RETURN. > >0 READ ERRORS DETECTED. > >REPEAT TEST? (Y/N) >" > >Maybe that gives you a clue as to what I'm working with. > >And if I try my HD disks it does this: (to every sector on every track) >" >READ RECORD NOT FOUND ERROR. >TRACK 0 SECTOR 1 > >READ RECORD NOT FOUND ERROR. >TRACK 0 SECTOR 2 > >READ RECORD NOT FOUND ERROR. >TRACK 0 SECTOR 3 >" >Last weekend that was my boot disk and I had several basic programs >compiled with basic-e on it. HD media is incompatable in every way with older drives and lower data rates. Drives used for HD media are 96tpi and track pasing ansd width are different, incompatability is oftenn the case or at best it gets by. Don't have Tarbell schematics handy to check. Does the read loop test a status bit or hang/wait on read? If it's hang wait on read is that also tied to interrupt?? If it's read a status bit two things: CPU MUST complete the read a byte loop in 32us (64 for mini floppy) and CPU speed makes this in some cases difficult. can you supply the sector read code? ( should be fairly short) >>Is the boot image set up for MITS 2SIO and does it set it up? > >I have a session captured from "once upon a time" when it booted >(which is more random than anything I can think of) > >"TARBELL 24K CPM V1.4 OF 7-20-79 >2SIO MINIFLOPPY VERSION. >HOW MANY DISKS? 2 >A>dir >A: CPM COM >A: SYSGEN COM >A: DDT COM >A: COPY COM >A: PIP COM >A: ASM COM >A: STAT COM >A: ED COM >A: FORMAT COM >A: DISKTEST COM >A: DUMPDSK COM >A: BASIC COM >A: RUN COM >A> >" Yeeha! >>I assume thse are in high memory and not below the address the image will >>try to boot to. CP/M wants from 0000h to system size as configured. > >My bytesaver is at C000 and 4k of sram for the monitor is at >E000. There is 24k of contigous memory at 0000. > >>Doesnt assure the FDC is set right for the drive and media. >>Also doesnt assure the media is SD or even bootable. >>Further is the media is not using a 2sio as the IO the system could >>boot and crash or appear to. > >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. >To add to that, I have myself booted off the setup, formatted disks, >made copies, ran the basic compilier, ran asm, etc. But something >(and I think its IN??? the tarbell card does not like me, Alaska, my >Altiar... I don't know! : ( Could be an interaction of both. > >A quote: >"My Imsai has a standard front panel with a factory suggested mod. to >do a power-on halt at zero. It has two 16K Industrial Microsystems >static ram boards, a SIO2 serial board and a SSM 8080 CPU. The prom >on the Tarbell is turned off to let the front panel operate properly >at power on. The Tarbell is then booted by using a MITS eprom board >and the 1702A eprom you burned for me. The power supply is a >Industrial Microsystems switching supply which powers both the drives >and the backplane But you don't have "that". You sorta have something like that. >Following is the different configurations I have used in the test >unit to boot the Tarbell; > 1. With a Z80 Cromemco ZPU set at 2Mhz, power-on jump set to >zero and no front panel. The Tarbell boots at power-on and will do a >cold boot every time you push the reset button. > 2. With a ZPU and Imsai front panel the Tarbell boots >only when the run switch is pushed. > > 3. With the Altair CPU and no front panel the Tarbell will not >boot at power on or after a reset! No suprize, the MITS CPU has no POJ, nada. It must be reset, load address and then run. > 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. > >After the Tarbell boards boot I have never had a problem or dropout >in CP/M with any CPU- front panel configuration. The static ram >boards use low power chips and run cool. thats good but getting there is an issue. >Remember my Altair CPU board uses a 8224 in the oscillator circuit >and I replaced the 8T97 with 74LS367's. >" The 8t97s worked fine for me. It has 8224? your mod or 8800B? >This is some info on the mod: >"The modification we have on our Tarbell boards was designed for the >5.25 Tandon TM-100 single sided. single density 48tpi drive which was >one of the first 5.25 drives produced. It might be that some of the >new 3.5 drives just won't work with the setup we are using." 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. The hub clamps sometimes off center the media and still media will sometimes drag the motor speed down. Watch for that. >>Could even be a simple bad IDC crimp on the cable. > >I have tried a few FDC cables. Maybe I should make a new one. Suggestions of the obvious. > >Time for bed. : ( > >Grant Don't know if it helps Allison

18 years, 5 months

Speaking of multiple processors...

by rtellason＠verizon.net

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?). I had a guy come into my shop one time wanting a couple of those fixed, but I could find *no* data on them at the time and therefore couldn't do too much for him... Are there docs out there for this beast? I'm just wondering how they divided things up between the two CPU chips, and how they interfaced things... -- 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

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 22:57:55 -0900 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > > >>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. > >Do you think that it would be better if I were to get the Tarbell to >run at 4MHz (250kHz)? > >I'd have to make a new BIOS and modify the format program. I don't >have source for the format program. Does anyone off hand know where >source to the Tarbell CP/M utilites could be found? Or utilities for any FDC based on 1771 could be modified. >I should be able to format the disk as 36 sectors 80 tracks and >possibly configure it to use both sides. That would be formatting it >to capacity... > >I'm going to write a disk image tool that dumps the disk to my >computer. I could write one that also writes an image to a disk. > >What do you think would happen if I were to try to use the disk at >250kHz but only put half of the sectors? Will the 1771 handle the >extra time or give me errors? Take the time to read up on 1771 and FDC formats before you just plunge in. You will arrive at a better solution and spare yourself wasted time. Not all 1771s where shipped as full speed parts too. >This faster signal might be better for the disk drive? Potentially. Remember FM floppy recording was passe' by the early 80s with every one needed far greater space. It want even a consideration buy time PC 3.5" floppies hit the street. >It may seem strange I'm fighting with this so hard, especially since >I'm working on Altair disk drive system emulator using SD cards, but >nothing beats real live hardware. : ) I can understand wanting a floppy, a real floppy. However I'd expect a goal such as being able to read 8" SSSD (cp/m standard) or other widely used format for archival or transfer. Another controller that ended up in altairs very often was the NS* MDS. It's hard sector but there is a lots of media and programs for it's DOS and also CP/M. Getting floppies is a pain however. Allison >Grant

18 years, 5 months

Colossus code-breaking again...

by julesrichardsonuk＠yahoo.co.uk

Nice article up on the BBC news website about the Cipher Challenge that's going on today: http://news.bbc.co.uk/1/hi/technology/7094881.stm ... I've not been involved in that side of things, but it's been interesting watching Tony and his crew running around the last few weeks trying to get everything put together (there was a huge amount to do on the reception/intercept side of things in particular) cheers Jules

18 years, 5 months

"Bally Astrocade"

by rschroeder＠satx.rr.com

I have a Bally Computer System,Astrovision Arcade Model ABA-1000-2. 7-controllers,1-video touch pad,11-games,2-Arcadian Cassettes,1-TV adaptor,2-key pad over lays,1-Bally Basic Computer Programming Cartridge With Built-In Audio Interface,and a complete set of manuals.

18 years, 5 months

Speaking of multiple processors...

by dm561＠torfree.net

----------Original Message: Date: Thu, 15 Nov 2007 21:32:19 +1300 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Intellegent peripherals (was Re: MIT provides MULTICS source and documentation (DPS-8 simulation)) <snip> The DOS for the 2040/3040/4040/8050/8250 drives had a "copy drive N to drive M" command (I'd quote chapter and verse, but I don't have access to the 'net right now). <snip> You could then, say, use your IEEE-488 acoustic coupler to logon to a BBS while disks were copying, or print to a printer, or whatever, since the IEEE bus was not involved in that disk-to-disk copy. <snip> -ethan ---------Reply: And if there was an error during the copy or backup the drive merely lit an error LED (which some people supplemented with a piezo beeper because it was easy to miss) and you had to ask the drive what the error was (and clear the error condition). That way whatever you were doing in the meantime would not be interrupted with an error message. You could also defragment (collect) the disk while doing something else, although for some reason the format (header) command tied up the computer until it finished. m

18 years, 5 months

Variations on Commodore monitors

by cfox1＠cogeco.ca

At 10:40 AM 11/15/2007, you wrote: >As part of the process of getting a second C128 system set up and >running, I recently ordered another Commodore 1084 monitor from an >eBay seller. The one I have is nice and bright and lets me switch >quickly between the composite (40-column) and RGBI (80-column) outputs >of the 128, so I was happy to stumble across another one for a >reasonable price. > >It arrived last night, and it's a great little monitor, in even better >shape than the one I already had. To my surprise, though, it's also >completely different. The case is different, the form factor and >positioning of the controls are different -- and, most relevantly, >even the connectors are different. My older one (made in 1989) has a >DB-9 input for RGBI input. The new arrival (made in 1988, if I recall >correctly) has an 8-pin DIN input for RGBI input. > >Thankfully, I already had a DB-9 to DIN-8 cable in the Big Box of CBM >Scraps, so I didn't have to order any cable-making parts from Mouser, >but it does bring up a question: how many potentially problematic >variations on the same model number did Commodore make? I know that >they did a lot of this sort of thing, given the ever-changing >appearance of the C2N and 1541, but is there a quick and easy question >I can ask a seller to find out exactly what ports to expect on the >back of a 1084 (or similar monitor)? "DB-9" and "8-pin DIN" are >already way too difficult to explain to somebody just trying to clean >out their attack, but if there's a guide out there with a breakdown by >manufacturing date or serial number for some of this Commodore >equipment, that would be lovely... I also have two 1084S Monitors, 1989 with Din, and 1991 with the DB connector. Both came with Amigas. Charlie Fox Charles E. Fox Video Productions 793 Argyle Rd. Windsor, Ontario 519-254-4991 N8Y 3J8 www.chasfoxvideo.com

18 years, 5 months

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