[cctalk] Re: Silly question about S-100 and video monitors
On 8/30/23 6:24 PM, Fred Cisin via cctalk wrote: Hence the short text lines on "home" computers. The TRS80 used an RCA TV, converted into a monitor. (presumably bulk purchased before the tuner was installed). OB_irrelevant: In the TV sitcom "Married With Children" in many seasons, on the Bundy kitchen counter was a [off white, instead of gray] TV of that model. I have one of these RCA TVs and will be displaying it along with the TRS-80 monitor to compare at Tandy Assembly this year. -- Eric Dittman
[cctalk] Re: VT180
Speaking of the VT180, I have one but am missing the disk drives and cable. Does any have a spare they'd like to sell? -- Eric Dittman
Re: TRS-80 Question
On 4/12/22 6:37 AM, Bill Gunshannon via cctalk wrote: So, this just gets more and more confusing. (Have I really been away from all this for that long!!!) I dug up the tech manuals for the two of them (buried deep in my stacks of books) and compared them. And you are, of course, right. Which just brings more questions. Why do Model I cassette programs (not BASIC) not run on the Model III? Why did they relocate a Model I program that had a specific Model III version to a slightly higher location in memory? It was common to add a loader for cassette programs that would load the program in higher memory and relocate to the original location so they could be loaded from disk (on both the Model I and Model III). This is because the original location would typically be in low RAM used by the OS. In some cases there wasn't a disk version of the program, in other cases it was to avoid having to buy the disk version. For games if there was a disk version the only likely change was to add a high score table that was written to disk, so not worth paying again. There were a few games that added extra features to the disk version but right now I can't remember which ones. I think Big Five did a few this way. -- Eric Dittman
Re: TRS-80 Question
On 4/11/22 1:33 PM, Bill Gunshannon via cctalk wrote: On 4/11/22 14:09, Eric Dittman via cctalk wrote: On 4/11/22 11:56 AM, Bill Gunshannon via cctalk wrote: Here's one for whatever TRS-80 gurus still hang out. The Mode 4 had 64K RAM and pretended to be a Model III by loading an image of the Model III Rom and then running it. Would it be at all possible to do the same thing with an image from the Model I and thus make a Model 4 capable of running Model I programs? The Model 4 had the Model III ROM included. It was the Model 4P that had to load the Model III ROM image from disk before operating in Model III mode. Not surprised I got that part wrong. But then, I use my 4P all the time and haven't touched a normal 4 or 3 in quite a while. There were some hardware differences between the Model I and Model III, such as the disk interface being memory-mapped in the Model I and port-mapped in the Model III, but if the Model I programs don't use anything that's different in the Model III then the Model 4 in Model III mode should be able to run them. So a game that's loaded from cassette should work but a game that runs from disk and writes to the disk won't work. Actually, the big difference is the memory map. Most Model 1 programs load right where the top off the Model III ROM sits so they can not be used on the 3 or 4. That's why I was hoping the ROM image trick could be used. I guess it was just wishful thinking. Thanks for the info, There's a 2K hole in the Model I memory map above the ROM, this space is used by the Model III ROM (12K ROM on the Model I, 14K on the Model III). After that you have memory-mapped I/O on the Model I. Both of them then have the keyboard mapped at 3800H and the video at 3C00H. RAM starts at 4000H on both of them. How the first section of RAM is used depend on whether you are using disk or cassette and if you are using disk then which OS you use. There's a good breakdown of how the RAM is used here: https://www.trs-80.com/wordpress/zaps-patches-pokes-tips/ram-addresses-and-routines/ -- Eric Dittman
Re: TRS-80 Question
On 4/11/22 11:56 AM, Bill Gunshannon via cctalk wrote: Here's one for whatever TRS-80 gurus still hang out. The Mode 4 had 64K RAM and pretended to be a Model III by loading an image of the Model III Rom and then running it. Would it be at all possible to do the same thing with an image from the Model I and thus make a Model 4 capable of running Model I programs? The Model 4 had the Model III ROM included. It was the Model 4P that had to load the Model III ROM image from disk before operating in Model III mode. There were some hardware differences between the Model I and Model III, such as the disk interface being memory-mapped in the Model I and port-mapped in the Model III, but if the Model I programs don't use anything that's different in the Model III then the Model 4 in Model III mode should be able to run them. So a game that's loaded from cassette should work but a game that runs from disk and writes to the disk won't work. -- Eric Dittman
Re: Vintage Computer Museum eBay Sales
It's a virtual museum using eBay to display the exhibits. On 6/17/21 9:48 AM, William Donzelli via cctalk wrote: Approximately zero people ever thought this guy was a museum. -- Will On Thu, Jun 17, 2021 at 10:28 AM Chris Zach via cctalk wrote: Reason #1 why I am exceptionally loathe to donate things to "museums" these days... CZ On 6/17/2021 10:06 AM, Bill Degnan via cctalk wrote: His target market is not the vcf hobbyist. Many of these were on ebay or wherever, shipped to Long Island and put back on ebay for 50%+ more than "wholesale" (orig. seller's price). I have sold items to this guy via ebay inadvertantly and he has relisted mynitems at a much higher price. It might take 6 months to sell at the higher price but eventually they sell. I wanted to sell quickly and was not willing to wait so my price was competitive. His profit comes from patience and apparently cheap storage. He probably re-uses the original shipping box which is smart! Personally I think people who scoff at this seller are missing the point ... we are mostly a group of educated frugal vc hobbyists and not his target market. But if you must have it, he's got it! Bill On Thu, Jun 17, 2021, 7:40 AM D. Resor via cctalk wrote: It seems at least on the first page of their listings, $899.99 is a favorite asking price? https://www.ebay.com/str/vintagecomputermuseumservices?_trksid=p2047675.l256 3 Don Resor -- Eric Dittman
Re: SCSI2SD
On 5/21/21 3:41 PM, Zane Healy via cctalk wrote: Does anyone have experience using a SCSI2SD board to replace a Hard Drive on a VAXstation or an AlphaStation? I’m thinking about using them on some of my systems to reduce the amount of noise. I’ve gotten used to a quiet office. :-) I've used one on a VS4000/VLC. I didn't have any issues. -- Eric Dittman
Re: Fwd: DDS Intertec SuperBrain attic find w/ OS and dust cover
I'd be interested if shipping was a possibility. On 5/17/21 2:40 PM, Eric Evans via cctalk wrote: Classic Computer Collectors, My name is Eric and I live in Baton Rouge, LA. A customer of mine recently asked me to find a good home for his early 1980's Intertec Superbrain. He told me that it worked the last time he used it in 198? after which time it sat in his attic with the dust cover on it. He provided me with a number of 5.25" floppy disks, which he said contained the complete operating system. The chassis appears to be 100% intact, and includes the dust cover. I can provide a few photos if you'd like. I have not yet been able to make contact with any other classic PC collectors, or museums that have expressed interest. Before I send it out to my local recycler, I thought I'd reach out and see if anyone might be interested. Thank you for your time & God bless, Eric Evans 225homebuyers.com 225.242.9858 gVoice 316.461.8587 cell -- Forwarded message - From: Dave Dunfield Date: Tue, May 11, 2021 at 11:09 PM Subject: Re: DDS Intertec SuperBrain attic find w/ OS and dust cover To: Eric Evans <4eric.ev...@gmail.com> Hi Eric, Sorry but no - I'm moving to smaller digs and have had to let much of my collection go and simply can't take on more right now. You might try the Classic computer collectors mailing list: http://www.classiccmp.org Dave Btw: In asking stuff like this it might be a good idea to state your (or friends) location. On Mon, May 10, 2021 at 5:22 PM Eric Evans <4eric.ev...@gmail.com> wrote: Dave, A customer of mine recently asked me to find a good home for his early 1980's Intertec Superbrain. He told me that it worked the last time he used it in 198? after which time it sat in his attic with the dust cover on it. He provided me with a number of 5.25" floppy disks, which he said contained the complete operating system. The chassis appears to be 100% intact, and includes the dust cover. I can provide a few photos if you'd like. I have not yet been able to make contact with any other classic PC collectors, or museums that have expressed interest. Before I send it out to my local recycler, I thought I'd reach out and see if you had any interest, or knew of anyone who might. Thank you for your time & God bless, Eric Evans 225homebuyers.com 225.242.9858 gVoice 316.461.8587 cell -- Eric Dittman
Re: Pipelining and Dec Jupiter thoughts....
On 5/7/21 5:07 PM, Zane Healy via cctalk wrote: On May 7, 2021, at 12:53 PM, Cameron Kaiser via cctalk wrote: Back in the mid-90s, there was an outfit in Britain which made some laptops using Alpha processors. That was the Tadpole ALPHAbook. Not many of those got to the outside world. Been watching for one for over a decade. For a period of time it was the fastest laptop available and it was reportedly not overly unpleasant to use (my Tadpole Viper, on the other hand, *is* unpleasant to use). There was a rumor inside DECin the same time-frame about DEC engineers prototyping an Alpha-based laptop (which never made it to market). The rumor included the internal code-name... "BURNS". I don't doubt it! I’ve had my eye’s out for one for more like 20+ years. I do have a Tadpole SparcBook 3GS (? something like that), that was a pretty cool system. These if I needed OpenVMS on a laptop, I’d simply run it via emulator or virtualization (not an option for Itanium). I gather that at least some development on OpenVMS 9.2 is being done on VM’s running on the developers laptops. I seem to recall that the Tadpole AlphaBook performance is roughly on par with the DEC Multia, which is to say, not very good. Though I don’t think I ever got OpenVMS running on my Multia. I have an ALPHAbook. You're right, it's about the speed of the Multia. The batteries I have are dead, but when they were still working the run time wasn't very long. -- Eric Dittman
Re: S-100 stuff, electronic stuff, model railroad stuff, books and magazines!
On 10/17/20 10:14 PM, Richard Pope via cctalk wrote: Hello all. I have 22 S-100 boards for sale. There are two backplanes. One is a 9 slot bare board and the other is a 19 slot fully populated board. Both boards have active termination. There are 8080, Z80, FDC, HDC, Serial, 68030, a Display board, a Front Panel board. There are also 3 Mean Well power supplies supplying the +9VDC and the +_16VDC. There are also voltmeters and amp meters . I want $500 plus shipping for all of it. I can provide a full inventory and pictures for anyone who is truly interested. I probably have cancer and if I do I am dying. I want all of this to go to a good home and not to the landfill. If anyone is interested I have some test equipment, electronic components, and model railroad equipment Please only serious inquires for I tire very easily. GOD Bless and Thanks, rich! Rich, I'm sorry to hear you may have cancer. I am interested in it depending on the cost of shipping, where are you located? -- Eric Dittman
VT525 power switch
I have a VT525 that I couldn't turn off. I took it apart and there's an adapter that connects the metal rod off the button on the front to the power switch inside. The adapter has crumbled and it feels like it was wax but it may have just been some plastic that has severely deteriorated. Before I try to work up some kind of replacement, has anyone already designed a 3D-printed replacement? I don't have a 3D printer but do have a friend that could print one for me. Otherwise, I'll see if I can come up with something. -- Eric Dittman
Re: 8 inch floppies
On 12/16/19 11:54 AM, Chuck Guzis via cctalk wrote: On 12/16/19 9:02 AM, Eric Dittman via cctalk wrote: I have two Aerocomp flippy drives. They have two index sensors and two write protect sensors so the disk doesn't need to be punched. They were in external cases with a system I bought and when I opened them for inspection before use I noticed the extra wires and sensors. Probably few folks remember what a struggle it was to develop a double-sided floppy drive. It's not just a matter of two identical heads, one on each surface... The system came with a bunch of disks. I imaged them as single-sided 40-track disks when I first got the system as that's what was normal for the system and when I looked at the images in an emulator they looked good. After I realized the drive were flippy drives I then had to go through the disks again with the flippy drive to make sure there wasn't anything on the other side (there wasn't). -- Eric Dittman
Re: 8 inch floppies
On 12/13/19 8:42 PM, Chuck Guzis via cctalk wrote: Believe it or not, the "flippy" was actually patented in 1974. US3932895A ...and let's not forget the 3" CF2 diskettes--designed to be flippies right fron the get-go. BASF certainly marketed 5.25" flippies: https://cdn.instructables.com/FWP/3D0Z/GXL5XZ3U/FWP3D0ZGXL5XZ3U.LARGE.jpg I have two Aerocomp flippy drives. They have two index sensors and two write protect sensors so the disk doesn't need to be punched. They were in external cases with a system I bought and when I opened them for inspection before use I noticed the extra wires and sensors. -- Eric Dittman
Re: P112
On 11/30/2019 8:34 PM, jim stephens via cctalk wrote: On 11/30/2019 6:15 PM, Richard Cini via cctalk wrote: The current P112 is a reissue from years ago, right? I remember I had one — and I may still have it somewhere — but I only used it with 3.5” drives. Somehow I think it was built that way by design (the board outline fit on a drive). I don’t know how available the code is, but I would look at the firmware on the board. To me it sounds like it has a bad drive definition. The 8272 is pretty easy to program for (I use it on my IMSAI). As an aside, I use a modified YD-380 (5.25” HD) drive to replace the 8” drives on my IMSAI so as a quick test you could use one of those. At least it can step to 80 tracks and has the same speed and bit rate. I have instructions on my site how to use it. Rich I have a archive and a board which I bought with the TCP option, as well as CF adapter, etc. I can share it if it's not available online Here is the contents I have. -rw-r--r--+ 1 1003 nogroup 915852 Sep 9 2000 bootdisk.img.gz drwxrwxrwx+ 1 1003 nogroup 270 Oct 9 2014 daveb drwxrwxrwx+ 1 98 98 674 Apr 9 2018 downloads-stack180 drwxrwxrwx+ 1 98 98 274 Apr 9 2018 gide drwxrwxrwx+ 1 98 98 954 Apr 9 2018 hal-bower drwxr-xr-x+ 1 1003 nogroup 574 Oct 9 2014 p112 drwxrwxrwx+ 1 98 98 552 Apr 9 2018 p112-2018 -rw-r--r--+ 1 1003 nogroup 331632 Sep 19 2014 p112-doc.pdf -rw-r--r--+ 1 1003 nogroup 14305 Sep 9 2000 rawrite.exe -rw-r--r--+ 1 1003 nogroup 357891 Oct 22 2005 sc102205.img.gz -rw-r--r--+ 1 1003 nogroup 445535 Nov 11 2005 sc05.img.gz -rw-r--r--+ 1 1003 nogroup 436332 Nov 30 2005 sc113005.img.gz drwxr-xr-x+ 1 1003 nogroup 3660 Oct 9 2014 tcj-archive drwxr-xr-x+ 1 1003 nogroup 268 Oct 9 2014 web -rw-r--r--+ 1 1003 nogroup 660331 Oct 17 2005 zs101805.img.gz -rw-r--r--+ 1 1003 nogroup 513625 Oct 21 2005 zs102205.img.gz -rw-r--r--+ 1 1003 nogroup 612086 Nov 11 2005 zs05.img.gz -rw-r--r--+ 1 1003 nogroup 552969 Nov 30 2005 zs113005.img.gz drwxr-xr-x+ 1 1003 nogroup 260 Oct 9 2014 zsdos -rw-r--r--+ 1 1003 nogroup 554479 Apr 22 2009 zsdos.pdf What's in the p112-2018 directory?
Re: TRS-80 Fireworks
I had the cover off one of the newer style Model 12/16B/6000 floppy expansion units (nicknamed "The Toaster"). As my wife walked by one of the Rifa caps blew and a fragment hit her shin. She was not happy. Mostly from the flash and loud pop. It also scared the cat that was sitting on a chair beside me. -- Eric Dittman
Re: DEC Pro380 problems
On 7/23/2019 7:45 PM, Paul Koning wrote: On Jul 19, 2019, at 10:52 PM, Eric Dittman via cctalk wrote: I pulled my Pro380 out of storage after getting a replacement VR201 monitor. I connected it all together and on powerup I get the following display: http://www.dittman.net/pro380/screen.jpg The tech manual says this is an error from slot 1 (the hard drive controller) and the error is "Non-existent memory trap occurred for longer than 20 seconds". I reseated all the cards. I noticed three ICs are missing on the hard drive controller but I don't know if they are empty or someone removed the ICs (I can't remember where I got this system). I can't find a picture of the controller to compare. The missing ICs can be seen here: http://www.dittman.net/pro380/missingics.jpg That's normal. I have a working 380 (well, last time I powered it up) and it has the same three empty sockets as yours. The description of the error code isn't very clear. It might mean that the card is detected (slot present register says there is a card) but the attempts to read the card ID code and associated selftest ROM failed. That would explain why the second line is 16 rather than the card ID (000401). You might need to clean the connector contacts (connector and backplane) and also check for damaged contacts. Okay, I looked at the slot and it looks like one of the first pins is missing: https://www.dittman.net/pro380/pro380missingpin.jpg I removed the HD controller and it fails to boot from floppy as well. The error codes change but seem to point to the RX50 drive being bad. I had another Pro380 but it's come up missing so I can't swap parts. I guess I'll keep an eye out for another one. -- Eric Dittman
DEC Pro380 problems
I pulled my Pro380 out of storage after getting a replacement VR201 monitor. I connected it all together and on powerup I get the following display: http://www.dittman.net/pro380/screen.jpg The tech manual says this is an error from slot 1 (the hard drive controller) and the error is "Non-existent memory trap occurred for longer than 20 seconds". I reseated all the cards. I noticed three ICs are missing on the hard drive controller but I don't know if they are empty or someone removed the ICs (I can't remember where I got this system). I can't find a picture of the controller to compare. The missing ICs can be seen here: http://www.dittman.net/pro380/missingics.jpg These are the installed option cards: http://www.dittman.net/pro380/cards.jpg Any ideas? -- Eric Dittman
Re: dBase IV for VAX/VMS (was WordPerfect 5.1+ for VMS)
On 7/18/2019 12:26 AM, Zane Healy via cctalk wrote: On a related note, was there ever a copy of dBase III or dBase IV for VAX/VMS? I know there was a version of Lotus 1-2-3. I don't know about the earlier versions but I have a copy of dBase IV for VAX/VMS that's still in the shrink-wrap. -- Eric Dittman
