test-drb

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101090 discussions

Need microprocessor trainer, oscilloscope advice?

by reevejd＠mchsi.com

Hello All. I'm new to this list and would like some advice on learning the inner workings of vintage computers. I have some basic experience with electronics and some simple measurement tools (multimeter, logic probe). So far, I've repaired a couple of older machines (Kaypro's, Compaq portables) but this has amounted to swapping dead hard or floppy drives, replacing dead batteries, etc. So here are my questions: (1) Is there a "trainer" system good for learning about microcomputer design and operation, and (2) would an oscilloscope be useful for this purpose, and if so, what Mhz rating is needed to work on older machines? I've noticed the price is directly proportional to this number! Thanks, John R.

19 years, 9 months

Early/mid-1980s "Portable Computer" magazine?

by evan＠snarc.net

Does anyone have issues of "Portable Computer" magazine from the early-mid 1980s? - Evan

19 years, 9 months

weird C implementations?

by alexeyt＠freeshell.org

I was reading the C language spec (C99) and I got to wondring: are/were there C implementations that had no stack, or a rising stack? There's a falling stack in every implementation I've seen, but the spec doesn't require it. Alexey

19 years, 9 months

CompuPro floppy controller differences

by ajp166＠bellatlantic.net

> >Subject: RE: CompuPro floppy controller differences > From: "Chuck Guzis" <cclist at sydex.com> > Date: Sun, 10 Sep 2006 16:37:41 -0700 > To: cctalk at classiccmp.org > >On 9/10/2006 at 3:53 PM Allison wrote: > >>>CCS did have some 5.25" disk formats (both 48tpi and 96tpi) supported. >>>I have no idea whether they ever used them as boot disks. >> >>I'd have to read the boot rom source. Who knows it's been years since >>I read the FDC manual so it could be wired in, the controller does >>do 5.25. I'd bet a penny there is no reason why not. > >Must be possible as my notes say all 5.25" formatsl reserved 6 cylinders*2 >sides for the boot tracks. On the 512 and 1024 bytes-per-sector versions, >that's about 60K. On the 256 byte/sector version its about 55K for the >boot. CP/M boot image is CCP (2k), Bdos(3.5k) and bios (.5k->3.5k), assuming a large bios the whole show is 9k. IF we add the two secondary boot sectors (assume 128byte sectors) to that it's 9.25k. Likely, even that is oversized. Standard SSSD 8" is two tracks reserved for boot(6656bytes!). Looked at the manual, the boot is generic enough that it grabs the first two sectors and jumps to that code. Sequence is Rom boot, seconday boot using the rom read/write routines and the seconday boot loads the whole show. That code is CCBOOT. The CP/M image once loaded jumps to BIOS Coldboot and that initializes everything and starts the show. The manual says two tracks on 8" and 3 tracks on 5.25 with track 00 being 128 byte single density only. NOTE the manual says tracks not cylinders. FYI: the standard rom has a MOSS monitor (console is 8250 at 40h) and also carries read write primitives and boot. If you had a board with 8250 serial on it that could be configured for address 40h that board would be easier to boot on a system without a boot disk in hand. Allison

19 years, 9 months

Broken Mac Accelerator

by trag＠io.com

>Date: Fri, 8 Sep 2006 22:41:09 -0400 >From: "Teo Zenios" <teoz at neo.rr.com> >My latest acquisition came in today, a Mac IIci, that I wanted to >use as an OS 6.08 machine > with a Daystar Turbo 040 (68040/33) accelerator. Anyway after >cleaning up the system and > I took the card out and notice there was a capacitor missing on the >back with a nasty looking > black burn mark. So I started looking around inside for the burn >metal part and notice I did not > smell or see smoke or little capacitor parts (its a surface mount >with no numbers on it) >So what I want to know is how the thing functioned at all without >the cap (burnt carbon acted > as a capacitor in some way)? and what caused it to stop working. It looks as if that cap (C54) ties the upper righthand pin of the oscillator, which I think is pin 14 or Vdd. As someone else wrote, it is probably just a decoupling cap, but it may be hard to tell for certain as I believe that the Daystar boards have more than four layers, which means that there are traces we cannot view. >If anybody have an original Daystar Turbo 040 33Mhz card with the >cache on a separate board > could you let me know (if possible) what value C54 s supposed to >be? The cap looks to be tied > into one or two legs of the oscillator chip that controls the CPU >(Ecliptek EC1100 16.667Mhz > 93-10). There are no markings on C54. It looks just like the two caps next to (below) it, but there are no characters which would betray a value. I don't have a capacitance meter. Jeff Walther

19 years, 9 months

Update Turbo Compilers

by RMeenaks＠olf.com

http://www.turboexplorer.com/ Cheers, Ram

19 years, 9 months

Stuff available

by djg＠pdp8.net

Work is moving to a new building after 20 years so some strange stuff is appearing. If multiple people want the same thing the one offering something PDP-8 in trade wins, someone with immediate need, otherwise I randomly pick. You pay shipping from 20817 Maryland. Email me direct if interested. 1) Multibus I stuff. Bus analyzer - hook up to terminal and capture whats going on on bus Wirewrap proto card - .3, .4, .6 dip capable Possibly an extender card - We used to have them but haven't seem them appear yet. 2) Stardent manuals and distribution tapes - heavy. 3) Intel PL/M 86, I2ICE, AMD 29k, TI 340xx (graphics processor) manuals.

19 years, 9 months

C64 and making doublesided floppies

by healyzh＠aracnet.com

Is there any problem with punching the left side of a floppy so you can write to the other side of a floppy in a 1541 drive? Zane -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | MONK::HEALYZH (DECnet) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

19 years, 9 months

Bigger hard disk on Toshiba 4010CDT

by rhammink＠delft.water.slb.com

Hi, Sorry to bother you, but after searching the web I found your posting (from 2004...). Since I want to upgrade the HD in my Toshiba as well, I wondered if you ever got it to work? Thanks for any info you can give me. Ric-Paul Hammink (Netherlands, also 4010CDT w/W95 and 96Mb) PS: background info: I cannot even get it to recognize a second identical 4.327Gb Toshiba hard-drive... (one partition FAT32), I just formatted it to 2x2Gb in FAT to see if it will recognize it now. Your original posting: Does anybody know how to get a Toshiba 4010CDT to accept a larger hard disk. It comes with 4 GB but when I want to work with three operating systems (MSDOS; modern Windows and LINUX) this will be a problem if I also want to include applications! Conversely, I am satisfied with the computer otherwise, although it is somewhat older by now, and would like to upgrade instead of retiring it or maintaining two Laptops in order to have space for the bigger operating systems. I did look at Toshiba's site but found nothing except some information that such support is NOT provided by them! They suggest an alternative company but this company does not show any sign of supporting my model. I also would be happier to find a way to alter the BIOS and buy a HDD locally, though I did find one company offering hard disks which they suggest will work with the 4010CDT, while giving no clue that they in some way deal with the BIOS problem. (In any case, it would mean importing the HDD, with a bunch of associated problems, especially if something goes wrong. I have my fill of that trouble!) Thanks to anyone able to help. Bob Answer from Andrew: On Thu, 2004-02-19 at 07:17, R. Mueller wrote: > Does anybody know how to get a Toshiba 4010CDT to accept a larger hard > disk. > I also > would be happier to find a way to alter the BIOS and buy a HDD locally, > though I did find one company offering hard disks which they suggest will > work with the 4010CDT, while giving no clue that they in some way deal with > the BIOS problem. www.shoptoshiba.com indicates that Toshiba has up to a 60 Gigabyte drive upgrade that is compatible with the Satellite 4010CDT. I got there >from a link on www.csd.toshiba.com , in case you were interested... So as long as you got your BIOS updated to 8.20 (found at <http://cdgenp01.csd.toshiba.com/content/support/downloads/1400cv82.exe>) you should be ok with going to your local computer store and getting a 2.5 inch hard drive up to 60 GB in capacity, and putting it into the little "carrier" thingamabob the original drive came in, and there you go... They want $379 for the 60 GB one, though... It comes with a 3 year warranty, so it might be ok... ENU (www.enuinc.com) in Portland has 20, 30, 40 and 60 GB laptop drives in stock, from $106 to $175... Before purchasing, you should get the original drive out of the laptop, open the carrier, and see where the mounting screws that mount the drive to the carrier are located. OLDER ones have the mounting holes in the corners of the drive, newer ones have them in towards the middle of the sides of the drives. Yours is probably a newer one. TTFN Andrew

19 years, 9 months

Commodore C128/A500 Power bricks

by joachim.thiemann＠gmail.com

>From my own (accidental) experiments, I found that if a C128 powersupply is used on an A500, the machine will seem to work, but appear to have a flaky floppy and sound. Most frustrating - I though my A500 to be junk material until I used the proper supply. The C128 on the other hand didn't seem to mind the Amiga supply, not surprisingly. Joe.

19 years, 9 months

CompuPro floppy controller differences

by ajp166＠bellatlantic.net

> >Subject: RE: CompuPro floppy controller differences > From: Fred Cisin <cisin at xenosoft.com> > Date: Sun, 10 Sep 2006 12:41:53 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> > I looked at the CompuPro disk image on Dave Dunfield's site and it's >> >for an 8" drive. The defining thing for me is getting a CP/M 2.2 image in >> >5.25" format. I've found another controller, from CCS (California Computer >> >Systems) that might work, too. So does anyone have a 5.25" CP/M 80 image for >> >either of these two boards? > >DSDD 8" should fit just fine on "1.2M" 5.25" > >On Sun, 10 Sep 2006, Allison wrote: >> All my CCS disks are 8" I'd have to look to see if the controller even did >> 5.25 it's been so long. I do remember the CCS used a banking scheme that >> didn't agree with most of my systems. > >CCS did have some 5.25" disk formats (both 48tpi and 96tpi) supported. >I have no idea whether they ever used them as boot disks. I'd have to read the boot rom source. Who knows it's been years since I read the FDC manual so it could be wired in, the controller does do 5.25. I'd bet a penny there is no reason why not. Allison

19 years, 9 months

Sorcerer, AIM-65, SYM-1 for trade.

by tosteve＠gmail.com

Folks, It has come to my attention that I have a total of six Exidy Sorcerer computers, and just as many Rockwell AIM-65's, and a few SYM-1's. While I like and enjoy them, I would like to trade one or two for a different exciting vintage computer of similar value (i.e. not a Sinclair 1000). Some things of which I am desirous: - GRiD Compass 1101 - Ohio Scientific - Sinclair ZX-80 - Heathkit H11 - Micro Ace - COSMAC VIP - Netronics ELF - Anything else of interest (1970's, S-100, etc...) Let me know- Steve in So. Cal. http://oldcomputers.net

19 years, 9 months

Commodore C128/A500 Power bricks

by healyzh＠aracnet.com

Will a C128 power brick be able to handle an Amiga 500? It looks to have a higher rating than the Amiga 600 brick I have (for that matter, can it drive an A500). Spent a lot of time up in storage, found a cable to let me hook my A500 up the the Commodore 2002 monitor I use with the C64, and *FINALLY* found a pair of Joysticks. Unfortunately they're Epyx 500JX sticks, and about the only sticks I've used that are worse might be Commodore's clone of the Atari sticks. Also dug up two more C64's (I think one is a C64c, do they say they're a "C" anywhere), a 1541 drive, a bunch of carts (including another Epyx Fastload), some software, and a printer interface. I seriously considered bringing the C128 and A500 back (thankfully found the external drive also today), but decided against the A500 since I wasn't sure about the powersupply and it was getting to hot to try to get back to the C128. Zane -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | MONK::HEALYZH (DECnet) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

19 years, 9 months

Commodore C128/A500 Power bricks

by billdeg＠degnanco.com

I have always used them interchangeably, but I never bothered to check. The jack fit, I used it. I *assume* that Commodore would not have made the 128 and A500's power supply ports be the same, unless they believed the associated power supplies were compatible. Otherwise it would be a product support headache. It would be a great advantage from a repair/supply perspective to be able to use the same supply brick. That said, only Commodore would do something as bone-headed as try to save money by using the same power supply jacks/ports with incompatible bricks! Bill D >Will a C128 power brick be able to handle an Amiga 500? It looks to >have a higher rating than the Amiga 600 brick I have (for that >matter, can it drive an A500). > >Spent a lot of time up in storage, found a cable to let me hook my >A500 up the the Commodore 2002 monitor I use with the C64, and >*FINALLY* found a pair of Joysticks. Unfortunately they're Epyx >500JX sticks, and about the only sticks I've used that are worse >might be Commodore's clone of the Atari sticks. Also dug up two more >C64's (I think one is a C64c, do they say they're a "C" anywhere), a >1541 drive, a bunch of carts (including another Epyx Fastload), some >software, and a printer interface. > >I seriously considered bringing the C128 and A500 back (thankfully >found the external drive also today), but decided against the A500 >since I wasn't sure about the powersupply and it was getting to hot >to try to get back to the C128. > > Zane >

19 years, 9 months

Commodore C128/A500 Power bricks

by aliensrcooluk＠yahoo.co.uk

--- "Zane H. Healy" <healyzh at aracnet.com> wrote: > > I did some looking and it appears that the A600 > supply is most > powerful of the A500/A600/A1200 supplies! However , > as I got the A600 > (and a pair of unstable A1200's) well after the > A500, this is a > pretty good indication that I have an A500 power > supply somewhere. > The odds are, wherever that is, is also where one of > my *good* Wico > Joysticks is :^) > > Zane > Err... I disagree with you Zane. I just checked both of my A500 PSU's (made in Germay) and my A600 PSU (made in China) and came up with the following: A600 PSU "Lightweight" (Part No. 391029- ) Input: 230-240V ~ 50 Hz 300 mA T1A Output: 5V 3.0A 12V 500mA -12V 100mA A500 PSU "Heavy Brick" (Part No. 312503-02) Input: 240V 50Hz 60W Output: + 5V 4.3A +12V 1.0A -12V 0.1A Going by those figures (on the underside of the PSU's), I'd say the A500 PSU is the most powerful. Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years, 9 months

Vintage Computer Festival 9.0(composite reply)

by roger.holmes＠microspot.co.uk

On 8 Sep, 2006, at 18:09, cctech-request at classiccmp.org wrote: > Whereabouts are you? About eight miles from Ashford in Kent. Ashford is where the channel tunnel rail link has its last station before France, called Ashford International. I am out in the sticks but I can e-mail maps. My home has a claim to fame, 'The Darling Buds of May' was filmed here and in the surrounding villages. > Of course, the perfect venue, history wise, would be H Block at > Bletchley > Park - the home of the WWII codebreaking Colossus machines and the > world's > first purpose-built computer building but its availability is still in > question..... Yes this would be the perfect venue. Is this the building due to house the computer museum? Roger Holmes.

19 years, 9 months

PDP-8/e EAE not working

by ajp166＠bellatlantic.net

> >Subject: Re: PDP-8/e EAE not working > From: Fred Cisin <cisin at xenosoft.com> > Date: Sun, 10 Sep 2006 12:48:55 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> Jay West wrote: >> > Woah! A "spare time generator"??? I want one!!!!!! >On Sat, 9 Sep 2006, woodelf wrote: >> But you need to supply a *flux Capacitor* .:) >> It still amazes me that a 4096 word computer >> can have hardware aided floating point. > >I don't have enough spare time to build one. >Besides, don't you need to connect a DC transformer to an AC battery to >make it work? > That might work. I was told a AC battery, A round Tuit and a green eyed lady were required. The problem is getting all three in the same room. Seems they are atomic. ;-) Now feet, do your stuff.. Allison

19 years, 9 months

PDP-8/e EAE not working

by chd_1＠nktelco.net

A couple of years ago I got an EAE off of ebay and it has never worked with my -8/e. I was looking at it again and see that my M8330 Timing Generator board is too early a revision to work with the EAE. I need at least rev B (I think). Does anyone have a spare M8330 they could part with? I kick myself for not grabbing a spare processor off of ebay over the years. Otherwise does anyone have a working EAE that would be willing to talk about with me?

19 years, 9 months

CompuPro floppy controller differences

by ajp166＠bellatlantic.net

> >Subject: RE: CompuPro floppy controller differences > From: "Chuck Guzis" <cclist at sydex.com> > Date: Sun, 10 Sep 2006 09:31:51 -0700 > To: cctalk at classiccmp.org > >On 9/10/2006 at 9:13 AM Allison wrote: > >>All my CCS disks are 8" I'd have to look to see if the controller even did > >>5.25 it's been so long. I do remember the CCS used a banking scheme that >>didn't agree with most of my systems. > >Yup, I've got samples for a CCS with 256, 512 and 1024 bytes/sector. All >are 48 tpi, MFM. So do I but all mine are 8". However having a H207 dual 8" makes it work as the h207 has a very similar size and look as the CCS crate (long to the back and narrow). As a result I've never fitted 5.25 to the CCS, no need. I've been tempted to fit 3.5" drives to it as it would do 720/780k formats as is off the 5.25 interface. All I'd have to do is tweek the BIOS for that(2S, 80C, 512 format) and maybe tweek the formatter for 80 cylinders and 2 sides. Allison

19 years, 9 months

2.4 Megabyte Floppies

by jwstephens＠msm.umr.edu

These are 5 1/4" form factor floppies, but hold twice the data. I have already searched ebay and google, so I need other suggestions, or someone who can part with some I don't know if regular or "premium" 5 1/4 inch 1.2mb media can be formatted and used with them or not. Thanks. Jim

19 years, 9 months

Broken Mac Accelerator

by compoobah＠valleyimplants.com

There is a chance that a little bit of carbonized something is providing enough of a load to hamper operation, though. Pull off the cap and see what happens. Also make sure that the board is intact, sometimes bits can get damaged by "blasting caps".

19 years, 9 months

VAXServer 3600 and MicroVax I in Seattle WA.

by michaelgreen42＠comcast.net

I've recently come into possession of a VaxServer 3600 and a MicroVax I that I'm taking offers on. Don't really know anything about them and of course no way to power up. They appear to be in fairly good shape except the MicroVax I has a little damage to the plasic in the front. I also should be comeing into possession of a Tektronics 25" Video Graphics Color Console and a few other things that were described as museum quality. Items are in the Seattle Washington area.

19 years, 9 months

CompuPro floppy controller differences

by ajp166＠bellatlantic.net

> >Subject: RE: CompuPro floppy controller differences > From: Allison <ajp166 at bellatlantic.net> > Date: Sun, 10 Sep 2006 09:13:54 -0400 > To: cctech at classiccmp.org > >> >>Subject: RE: CompuPro floppy controller differences >> From: "Richard A. Cini" <rcini at optonline.net> >> Date: Sat, 09 Sep 2006 13:59:08 -0400 >> To: "'General Discussion: On-Topic Posts Only'" <cctech at classiccmp.org> >> >>All: >> >> I looked at the CompuPro disk image on Dave Dunfield's site and it's >>for an 8" drive. The defining thing for me is getting a CP/M 2.2 image in >>5.25" format. I've found another controller, from CCS (California Computer >>Systems) that might work, too. So does anyone have a 5.25" CP/M 80 image for >>either of these two boards? >> >> Thanks. >> >>Rich > >All my CCS disks are 8" I'd have to look to see if the controller even did >5.25 it's been so long. I do remember the CCS used a banking scheme that >didn't agree with most of my systems. I decided to pull out the CCS system and check. I'd forgotten as it smaller than most s100 crates and it gets tucked away easily. It does do 5.25" though the docs refer to 8" disti media only. The Eprom on mine has the MOSS monitor and boot, IO expects standard CCS. If you have CCS IO you at least have a monitor. Allison

19 years, 9 months

Broken Mac Accelerator

by teoz＠neo.rr.com

My latest acquisition came in today, a Mac IIci, that I wanted to use as an OS 6.08 machine with a Daystar Turbo 040 (68040/33) accelerator. Anyway after cleaning up the system and installing the OS I put the card in and loaded the drivers and all was fine (very fast booting). After about 15 minutes I had to reboot for driver update and the system would just bomb during boot (about where the control panel for the Daystar card would want to load). I took the card out and notice there was a capacitor missing on the back with a nasty looking black burn mark. So I started looking around inside for the burn metal part and notice I did not smell or see smoke or little capacitor parts (its a surface mount with no numbers on it). Doing a little digging in my picture archive I verified that the card which I have never used before (which is why I wanted a IIci since it works in that model) was sent to me in this condition. So what I want to know is how the thing functioned at all without the cap (burnt carbon acted as a capacitor in some way)? and what caused it to stop working. If anybody have an original Daystar Turbo 040 33Mhz card with the cache on a separate board could you let me know (if possible) what value C54 s supposed to be? The cap looks to be tied into one or two legs of the oscillator chip that controls the CPU (Ecliptek EC1100 16.667Mhz 93-10). I kind of want this working again since it will be a long time before I find another one at a great price. Thanks TZ

19 years, 9 months

CompuPro floppy controller differences

by ajp166＠bellatlantic.net

> >Subject: Re: CompuPro floppy controller differences > From: "Dave Dunfield" <dave06a at dunfield.com> > Date: Fri, 08 Sep 2006 22:35:38 -0500 > To: <cctalk at classiccmp.org> > >> Is there any practical difference between the CompuPro Disk 1 >> and Disk 1A that would prevent a 1A disk from working on a 1? I have a line >> on a Disk 1 controller but only have access to 1A disks from Dave Dunfield. > >I have a Disk-1A up and running in my Compupro box - unfortunately I do not >have a Disk-1 to test with. I do however have manuals for both controllers. > >>From what I can tell on a cursory readthrough - the Disk-1 and the Disk-1A >are very similar, but not identical: > > - The Disk-1A appears to have some functions available in the write side > of some registers which were read-only on the Disk-1 - these seem to > control features that had to be set by switches or board modifications on > the Disk-1. > >- The Disk-1 has a bit-bang serial port which has been dropped on the 1A. > >- The difference is NOT the difference between a 765 and a 765A - both > manuals list the 765A as the NEC FDC. > >- The 765 and motor control registers appear to be in the same place on > both controllers. > >I have a set of original Cromemco CP/M diskettes, and the labels do NOT >mention anything about a specific floppy controller board - my guess is that >the disks would boot and run on either controller. (But as noted above, I >cannot confirm this, so it is just a guess). > >Dave You missed one item, different eprom and contents. The differences there include boot code for 8088 and in very late 1A version 68000. They are essentially the same, though of the two the latter 1a is prefered. Allison

19 years, 9 months

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