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Classic/Retro computer thread — Parallax Forums

Classic/Retro computer thread

kwinnkwinn Posts: 8,697
edited 2011-07-17 11:48 in General Discussion
How about adding a Classic Computer or Retro Computer thread Forum for projects involving a propeller to emulate old computers or provide I/O and such to old microcomputer chips.

Also, I am trying to find a data sheet/manual for the "CMOS 1702 ?" microprocessor. I have found a bit of data on the instruction set but not much about hardware and timing. It sure would be nice to have an archive where all the info for the old micros is available. Perhaps that could be added as well?

Comments

  • LeonLeon Posts: 7,620
    edited 2011-07-10 13:14
    Don't you mean the RCA CDP1802 or COSMAC?

    It's still made by Intersil as a hi-rel device and there are some FPGA implementations of it.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-10 20:48
    Leon wrote: »
    Don't you mean the RCA CDP1802 or COSMAC?

    It's still made by Intersil as a hi-rel device and there are some FPGA implementations of it.

    Yes, that's the one. Only worked with it a few times so it did not make much of an impression. At least I was only off by a hundred. Many thanks Leon.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2011-07-10 20:57
    There are already some groups out there dedicated to the CDP1802 CPU and systems. Here are a couple:

    http://groups.yahoo.com/group/cosmacelf/

    http://groups.yahoo.com/group/sparetimegizmos/
  • kwinnkwinn Posts: 8,697
    edited 2011-07-10 21:49
    RobotWorkshop wrote: »
    There are already some groups out there dedicated to the CDP1802 CPU and systems. Here are a couple:

    http://groups.yahoo.com/group/cosmacelf/

    http://groups.yahoo.com/group/sparetimegizmos/

    Thanks for the info.
  • Mike DenchMike Dench Posts: 13
    edited 2011-07-11 03:45
    My two favourite old computers that I wish I still had are the 48k Sinclair Spectrum (or Timex-Sinclair 2068) and the Amiga 1000. I wouldn't be here trying to get back into Basic controlled circuits if it wasn't for Sinclair Basic the best version of which was on the 2068 with added features that made editing much easier. It had great string handling and arrays. I'd give a lot to have a powerful modern computer that ran a command line Basic even if it did mean fiddling the OS to make it possible.

    In 1982 I wrote a graphics program for my Sinclair that let me add animated titles to VHS video which doesnt sound like a big deal but believe you me it was. It got my graduating practical grade bumped from a B to an A by an outside adjudicator who told my tutors "Do you have any idea how much it took to do this?"

    The Amiga I just fell in love with its capabilities, what a really phenomenal machine it was in its day. It took a long time for PC's to catch up and even now there isnt the software with the capabilities and ease of use of DeLuxe Paint 4 especially for cel animations. I tried a few others but those two machines stand out and I still run a Sinclair Basic emulator on my PC. It may only be a Tiny Basic but its a joy to use and almost idiot proof which is a major plus in my book.
  • HumanoidoHumanoido Posts: 5,770
    edited 2011-07-11 06:38
    kwinn, are you thinking about emulating the 1802 with the prop chip?


    This site is very good, and includes links to a freeware emulator for the Mac and Palm.
    http://www.cosmacelf.com/
    Lots of old documents are scanned and available for download.

    You can learn a lot about modern computers by studying one from the days of disco! TinyELF for Mac OS X brings emulation of 1802-based microcomputers to the Macintosh platform, and runs on OS X 10.4 (Tiger) or greater. TinyELF features pixie graphics, single-step debugging, a CPU state viewer, program execution trace, breakpoints and more. Its help book includes a full tutorial on computer fundamentals and programming.
    http://www.tinyelf.com/
    download here http://homepage.mac.com/ruske/tinyelf/TinyELF.dmg

    Cosmac Elf 2000
    http://www.sparetimegizmos.com/Hardware/Elf2K.htm

    1802 Emulator for Windows
    http://emulationrealm.net/modules/wfdownloads/singlefile.php?cid=457&lid=1131

    http://incolor.inetnebr.com/bill_r/computer_simulators.htm

    draft_lens13464551module128229871photo_1287795800elf-II.jpg
    The price was right!
    http://www.squidoo.com/cosmac-elf

    Learning assembly language with TinyELF Comsac ELF emulator
    http://www.notanon.com/programming/learning-assembly-language-with-tinyelf-comsac-elf-emulator/2010/04/29/
  • Pharseid380Pharseid380 Posts: 26
    edited 2011-07-11 14:01
    Was the 1802 rad-hard or was there a rad-hard version of it? I dimly remember a list of micros that were qualified for use in space at that time and I think the 1802 was on it. Maybe just using CMOS with those relatively enormous design rules made it somewhat rad-hard.

    -phar
  • ctwardellctwardell Posts: 1,716
    edited 2011-07-11 14:08
    Pharseid380 wrote: »
    Was the 1802 rad-hard or was there a rad-hard version of it?

    There was a silicon on sapphire version used for space operations, the standard devices are not rad-hard.

    C.W.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-11 17:28
    @ Mike Dench. In 20/20 hindsight it was amazing what was done with those early micros. I ran a business using a Z80 that started with 16K of ram and 2 88K floppies. It was upgraded to 64K and larger floppies later, but even at the beginning I did my quotes, invoices, accounting, and all the other sundries that go with running a business on that computer.

    @ Humanoido, thanks a lot for those links. To answer your question, no I am not thinking of emulating the 1802 with the prop chip. I am looking to replace a large number of cmos, ttl, eprom, and ram chips surrounding a CDP1802 with a prop, 64K ram, and a couple of driver chips. The idea is to copy the software from the 2708 eproms, store it in a serial eeprom, and have the prop load it into the 64K ram and then letting the 1802 boot from the ram. At that point the prop becomes the I/O circuit for the 1802 and the front panel controller for the instrument.
  • UnknownUnknown
    edited 2011-07-11 18:54
    The Propeller As A Micro Computer
    http://forums.parallax.com/group.php?groupid=7

    Don't forget that making a computer in the past has been a job for companies or very talented individuals. One of the reasons people abandoned the field was because it just cost too much and they couldn't keep up with companies.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-11 19:51
    Thanks for the link Chuckz. That's an area of the forum I was not aware of. Looks interesting.
  • Mike DenchMike Dench Posts: 13
    edited 2011-07-12 05:33
    kwinn wrote: »
    @ Mike Dench. In 20/20 hindsight it was amazing what was done with those early micros. I ran a business using a Z80 that started with 16K of ram and 2 88K floppies. It was upgraded to 64K and larger floppies later, but even at the beginning I did my quotes, invoices, accounting, and all the other sundries that go with running a business on that computer.

    I built my own 300 baud modem and hard disk interface for my 2068 and ran a bulletin board from it back in the late 80's!

    You will know, if you used a ZX80, just how idiot proof their TinyBASIC was, it may have been a limited version but what they got out of it was amazing and especially the built in parser that gave you a flashing ? instead of letting you enter a buggy line. It didnt just catch bad syntax it also caught GOSUB's without RETURN's and several other little things which whilst not 'wrong' as such would have caught up with you sooner or later. Saved me hours of retyping even if occasionally it took a while to figure out what I had done wrong.

    UDG's (user defined graphics) were what I particularly liked. I did my video titling trick by using them to make 8 characters which could be combined to form all the letters of the alphabet and 0 to 9 and then over wrote the keyboard character map space thus squeezing a few more bytes of performance out of it.

    For me, the crucial aspect of the Sinclair was that it made Basic easy to use and fun to do. I wrote all sorts of tiny useful little programs like my teachers grade book fiddler that massages the data to ensure a bell shaped standard curve of distribution so my Scantron sheets didnt ring alarm bells in the Guidance office!

    I used to be a complete mathphobe and the Sinclair taught me not to be afraid of it because programming simple calculations forces you to think logically and once you've gotten past that hurdle, the rest becomes a lot easier. Seeing an equation play out in visual form on screen is enlightening instead of being frightening!

    I was a 'shop' teacher and I got my students interested in programming in Basic by approaching it from a fun angle. "Hello world!' I ask you, what could be more boring? Programming your sound chip to make fun sounds now that's more like it! I held a farting contest using Basic (how apt!) and they really threw heart and soul into that one.

    The Sinclairs Achilles heel was that damn edge connector, no proper I/O ports. Also Basic isn't a good language for controlling machines with. Seymour Paperts (?) LOGO on the Apple 2 was much better in that respect. Oh well, that was then, this is now and I'd better get up to speed I can see that from all I have been reading here, I feel like a blasted ammonite never mind dinosaurs!
  • kwinnkwinn Posts: 8,697
    edited 2011-07-12 18:07
    I know what you mean. I started programming and servicing minicomputers a couple of years before the first microcomputer kit came out and have been struggling to keep up with it all ever since. On the plus side, how many careers are there where you find yourself just as interested and challenged after 35+ years as you did when you started.
  • prof_brainoprof_braino Posts: 4,313
    edited 2011-07-12 20:41
    Mike Dench wrote: »
    I held a farting contest using Basic (how apt!) and they really threw heart and soul into that one.

    Brilliant! I am now considering holding a contest called "Farting around with Robotics" at the kids' school. I can see this getting a lot of attention just from the name. I better move this to its own thread.

    Did you look at the Hive project http://hive-project.de/ ? It's "retro-style", but uses the prop and is about 24 bits more modern than many classic computers. The fellow sent me a bare board, he wanted forth on it. I'm a software guy, and never poked at the hardware much. I get able to build a full computer, from parts that I soldered together myself. This is kind of a big deal for a software guy.

    Thanks again for the fart contest story!
  • Mike DenchMike Dench Posts: 13
    edited 2011-07-13 03:14
    The site you mention appears to be in German, I am unable to make much sense of it. 'Ein grossen bier bitte,' is about my limit!
  • prof_brainoprof_braino Posts: 4,313
    edited 2011-07-17 11:48
    Mike Dench wrote: »
    The site you mention appears to be in German, I am unable to make much sense of it. 'Ein grossen bier bitte,' is about my limit!

    Just noticed this,

    I used Google Translate and built the whole thing without know anything about German or electronics.

    Go for it!
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