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101090 discussions

Solderless breadboarding (and 68010 vs 68000)

by ethan.dicks＠gmail.com

On 2/19/10, Tony Duell <ard at p850ug1.demon.co.uk> wrote: >> Yes, I have been using breadboards for more than 20 years and never >> had a problem with them. Sure, you must not try to stick thick wires > > I must have been unlucky. I tried several of them in my younger days > (Eurobreadboars, the CSC/GSC Protoboards, etc) and had no end of > problems. In the end I started just soldering upo the circuits on > stripboard, and my desigens started working first time. I've done both. I've personally never had mechanical stability problems with protoboards, but then I don't tend to wedge in 0.1" header pins into my boards. I insert ICs, 1/4W resistors, various capacitors, wires, crystals, LEDs and such, but rarely do I insert header pins. I've always felt that they were "too large", even though I know lots of people stuff them in there all the time. > [1] The local pound shop (a similar concept to dollar stores) was selling > a camping lamp with 24 white LEDs for a pound. I'd buy that for a pound! (and repurpose it, as you have). >> BTW, the article says it is an MC68008, so you did not need to count >> 24 pins (on one side) :-) > > Oh, I didn't . I noticed it was a 0.6" wide package. The 68000 and 68010 > DIL packages are 0.9" wide. Indeed. Quite distinctive. >> The 68010 is pin compatible to the 68000, but if you are in OS stuff, > > Indeed. There is also a PGA version of the 68010, which is used in some > HP machines IIRC there's a 68012 which had more addres mins bought out, > but otherwise had the same PGA pinout I have read about the 68012, but don't think I've seen one in the wild. >> you have to modify some software if you are handling stack frames. >> Those are not identical on the 68000 and 68010. > > IIRC, the 68010 pushes more onto the stack on an interrupt. It does. The difference isn't onerous - at least starting with AmigaDOS 1.2 if not 1.1 (not sure about 1.0), you could upgrade your 68000 to a 68010 for an approximate 5% effective speed "boost" - this was entirely due to the one-instruction DBcc "loop-mode cache" in random places in the OS and in applications. As long as your applications didn't try to execute any "MOVE from SR" instructions (http://www.cpu-world.com/CPUs/68010/), no changes were required. If you _did_ have some apps that did that, there a trap handler for that on, IIRC, an early Fish disk. It would catch the privilege exception, grab the status/condition code value and return the value to the trapping instruction. One app that was used to tell if you had the patch applied was the AmigaDOS 1.1 calculator. With AmigaDOS 1.2, the app made an OS call to get the required value. The older app used a "forbidden instruction" so it made a good test. If you are rolling your own OS or writing embedded code, it's not really that hard to determine what size of stack frame you'll have and handle both. I was responsible for replacing 68000s with 68010s in the final COMBOARD product (partially to take advantage of "loop mode" when dumping buffers across the DMA interface, increasing the block speed of the board with a $50 chip). I don't think the code changes relating to the 68010 took me more than part of an afternoon to implement. It's good to remember that it's so, but rather easy to accomplish once you are that deep in the code. -ethan

16 years, 2 months

HP 9825 tape drive

by rikbos＠xs4all.nl

I modified a HP 9825A tape drive for use with QIC 40/80 tapes. It's a rather easy conversion building a new capstand wheel witch is a little higher so it can drive the QIC tapes and increasing the write current by replacing a the current limiter resistor. It's under test and at the moment seems to work. I was curious if there others who did the same and what theire experiances are... -Rik

16 years, 2 months

flowcharts and teaching programming

by bqt＠softjar.se

uss Bartlett <arcbe2001 at yahoo.com> wrote: > Don't forget that the DO loop in Fortan has not the same effect as an iteration as the Do condition is performed at the end.? The DO component is therefore performed at least once.? An iteration must be able to be performed zero times.?? This was why in JSP it wasn't used. It differs. What you describe is how it is in FORTRAN IV and older. It was changed in FORTRAN 77, so that a DO loop can run zero number of times as well. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

16 years, 2 months

Identifying a classic board and find software for it ...

by gerhard.kreuzer＠liftoff.at

Hi, sombody donates a board to my collection, www.compuseum.at, maybe there is anybody outside helping me to identify this board. Its a PDP11 subsystem on an ISA board. Labels found: AT.S, PCCB ROI-931007. The PDP11 chip is one of this big nice ceramic carrier, holding two chips, numbers were: HD4-6900-5 DC334, produced 9338, and ...6901... repectively. As he told me, they used a standard OS2 box to run this 'machine'. He also will try to find something, but he isn't sure that there is anything left exept this nice board. As far as I know, it was part of a building management system, produced by Landis & Gyr and maybe used or co-developed by Siemens. Thanks for helping Gerhard

16 years, 2 months

Northstar Advantage ?

by rescue＠hawkmountain.net

All this talk of S100/Northstar/etc.... make me remember what I believe was a Northstar Advantage I used for a bit in college..... I remember it was laid out like a Radio Shack Model III system... all in one, monochrome screen with 2 floppy drives built in to the right, etc.... I've always wanted to find one of these.... but never have... I'm not sure my memory is even correct (is it the Northstar Advantage ?). Anyone have one in the MA/RI/NH area have one they don't want ? -- Curt

16 years, 2 months

HP 9825 tape drive

by hp-fix＠xs4all.nl

16 years, 2 months

Exidy Sorcerer II schematics?

by wh.sudbrink＠verizon.net

Next up on my workbench is a Sorcerer II. I've googled about some and have found the original Sorcerer schematics. I've also found plenty of references to and pictures of the Sorcerer II board but no schematics. I got the machine from Europe so I suspect it may be hacked for 220V 50Hz. The power cord is cut off so I don't know for sure but there is definite evidence of hand soldering on the PS. Any help greatly appreciated, Bill

16 years, 2 months

Commodore 1520 Plotter

by healyzh＠aracnet.com

I'm going through some stuff my Aunt brought me last month, she's apparently helping someone that was seriously into Commodore computers clean out. In the pile is a Commodore 1520 Plotter. I had one of these back in the 80's. Am I correct that there isn't any source of pens any more? Of course I haven't even had time to see if it works. The real treasure is all the books. There are dozen's of books on the VIC-20, C-64, and electronics (lots of Radio Shack books from the 70's and 80's, and other books). There are at least the first two Compute Guide to the VIC-20 and the first 3 for the C-64! :-) 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/ |

16 years, 2 months

Sanyo CP/M machine and Macintosh IIfx

by dbetz＠xlisper.com

I have a friend who has a Sanyo MBC-1000 and a Macintosh IIfx with both a two page monochrome monitor (nicknamed the "Kong") and a 13" color monitor that he'd like to pass on to someone who will appreciate them. The catch is that they are in the San Francisco Bay Area and would need to be picked up within the next few days. I am in the area right now and could help with the pickup but I am leaving the Bay Area on Friday. If anyone is interested in one or both of these machines, please contact me off list. His description of the Sanyo is: "Sanyo MBC-1000. I've got manuals and software, including Aztec-C and BIOS source. The computer itself is very solid and was in perfect working condition when I last used it." If I don't find someone to pick up these machines in the next few days they will likely go to a recycler.

16 years, 2 months

Sanyo CP/M machine and Macintosh IIfx

by bbuckels＠mts.net

Hello There, I am interested in the Aztec C disks and manuals. I am able to pay shipping costs through paypal. I am in Canada. I am also interested in old computers but unfortunately the shipping costs to Canada make that impractical. Regards, Bill Buckels Box 277 177 - 6th Street South Beach Gimli, MB, Canada R0C 1B0 Home - (204) 642-8405 Cell - (204) 612-4162 Please see my links below: http://en.wikipedia.org/wiki/User:Bill_Buckels http://www.cpm8680.com/ http://www.appleoldies.ca/ http://www.c64classics.ca/ http://www.aztecmuseum.ca/ x--- snip ---x Sanyo CP/M machine and Macintosh IIfx David Betz dbetz at xlisper.com Sun Feb 28 22:47:58 CST 2010 I have a friend who has a Sanyo MBC-1000 and a Macintosh IIfx with both a two page monochrome monitor (nicknamed the "Kong") and a 13" color monitor that he'd like to pass on to someone who will appreciate them. The catch is that they are in the San Francisco Bay Area and would need to be picked up within the next few days. I am in the area right now and could help with the pickup but I am leaving the Bay Area on Friday. If anyone is interested in one or both of these machines, please contact me off list. His description of the Sanyo is: "Sanyo MBC-1000. I've got manuals and software, including Aztec-C and BIOS source. The computer itself is very solid and was in perfect working condition when I last used it." If I don't find someone to pick up these machines in the next few days they will likely go to a recycler.

16 years, 2 months

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