• Please review our updated Terms and Rules here

Recent content by GilesGoat

  1. G

    NEC 7811G can ROM be disabled ?

    Hi Guys, I stumbled upon a NEC 7811G microcontroller, it seems 7811G is the ROMed version. However datasheet I found are not 100% clear on the use of pins MODE0 and MODE1 , the say that in the 7811 MODE0 SHOULD be grounded ( note SHOULD not MUST ) while MODE1 SHOULD be pulled up. This would...
  2. G

    An single computer board based around the SG2650

    Hi guys, to avoid confusion and/or also going off topic in that thread where I was asking about that Microworld Basic I decided to start a new one. So the story goes more or less like "years ago someone gave me a bag full of weird chips, some where exotic CPUs, to preserve the memory of all...
  3. G

    Looking for a dump/source of MicroWorld BASIC Interpreter for the 2650

    Hi guys, as the title says : "Looking for a dump/source of MicroWorld BASIC Interpreter for the 2650". Long time ago I made this system, I think I talked about it somewhere else can't find the reference : Picture of the semi-finished board. It contains a "bootloader" that allows to...
  4. G

    Old Atari CPU 90-6001 185 C27805

    I have this chip, it's not very readable, there's an Atari logo and says 90-6001 185 C27805, not sure about that '6001' could be '6081'. It's a 40 pin dip. I believe this is similar to an NTE6800 CPU which I am not sure but I think it should be equivalent of a Motorola 6800 CPU. Is that the...
  5. G

    Cm* machines, reading a DEC book.

    I was reading/browsing around a book titled "Computer Engineering, a DEC view of hardware system design", chapter 20 of this book is dedicated to the story of this Cm* cluster and all the analysis that followed. I was wondering, does it still exist any of those ? Is there any still working (...
  6. G

    Documenting and rechecking.

    So yesterday I had a bit of time again to work on this thing, to fight a bit also the "dentist's discomfort" I decided it was about time to recollet all the ideas and write them down so I began to write documentation about this thing ( was too tired to debug/check VHDL ). It usually helps me...
  7. G

    Fixing things ..

    I had a little bit of a play with the thing .. "amazing" how many silly little logic bugs you can make when you think a thing and you do another .. Ok so after some test with the VHDL simulator ( ModelSIM, evaluation ) turns out a couple of signals had the wrong polarity, another wasn't...
  8. G

    De-Bugging

    So just to say had quite a few busy days, however I managed to continue to work a little bit ( a few hours ) on all this and found quite a few silly bugs. The VHDL code as posted here does not do exactly what it should do there are various stupid errors there and there. However when I'll have...
  9. G

    The project so far.

    So let's talk now about the status of the project. The status of the project is that yesterday night I finished re-checking everything and tried to create "the netlist" and see what was coming out, after a bit of a battle with some missing footprints, a couple of mis-labellings and a silly...
  10. G

    An ongoing T-11 project.

    So I decided to try to use this blog facility as a place to keep a bit of track/history of what is actually now became "the T-11 project", I think we are going maybe a bit too off topic from the thread that started it all so I think a blog could be a better place to continue it. But first of...
  11. G

    Looking for a datasheet DEC T11 Cpu

    Hi, I stumbled across a DEC T11 CPU ( 10 Mhz I suppose ) which is actually on a board of a "Championship Sprint" Atari videogame. I was trying to find out some datasheet of it, any idea where I could find any ? It would be tempting to use it to build something small computer with it. Thanks...
  12. G

    Trying to fix an Hantarex POLO 20"

    Hi, ok I do have an Hantarex POLO 20 monitor, that up to some time ago it was working pretty well. Then .. I think what happened we had some "serious power glitch" .. the monitor started to behave quite oddly until it got the point of "no image". For quite some time I left it there, now I am...
  13. G

    XA1541 adapter + cable PC troubles

    Ok "don't shoot me now" ( yet ) I know I should first try all this with a real CBM before to get to any conclusions. But just a few questions/doubts/things to know. Yesterday I built this : I used 4K7 resistors and 2N3904G transistors, despite they say 'it may or it may not work' I cannot...
  14. G

    Brief history of a home built machine.

    Hi guys, new to the forum ( joined yesterday ) as this is one of the few things I actually quite "documented" in the past times you may be interested in have a look at it. This is a CP/M ( 2.2 ) running machine I built some years ago from scratch starting literally from a bunch of components I...
  15. G

    Hi, new to the forum, fixing a Commodore PET

    Hi guys, I hope I am not going to break some rule in starting a new thread about this, it could have gone maybe into that "Random characters on a PET screen" because that is the symphtom but let's go in order. I joined this forum just today after suggestion cause "here seems the right place to...
Top