zx spectrum +2A modulator

hi specy world , i recently sold a specy +2A with a modulator that looked different from the normal astec jobs .. it was VM-516/E36 b/wave inc taiwan and it gave a really clear RF picture (best i have seen) . was this a factory unit or a mod?it looked more modern inside, i was not able to find any details of this unit.

Comments

  • It would have been nice if you had taken a picture of it and of the board it is fitted on...

    Also do you know which country this computer was originally sold in?

    The standard modulator was the ASTEC UM1233 E36 UHF Modulator Channel 36. The vast majority of U.K. designed home computers that had a UHF output used ASTEC modulators.

    Mark
  • Yes it's fitted to the +2B made in china models with the issue 2 revision boards. You'll find these in the James Bond pack +2's.

    Mobo-Front.jpg
  • 1024MAK wrote: »
    Also do you know which country this computer was originally sold in?
    I think the frequency of X200 would give more of a clue than the RF modulator’s brand itself. If it’s anything other than 6 MHz, the Speccy clearly was not meant for the UK market.
    Every man should plant a tree, build a house, and write a ZX Spectrum game.

    Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
    and zasm Z80 Assembler syntax highlighter.
    Member of the team that discovered, analyzed, and detailed the floating bus behavior on the ZX Spectrum +2A/+3.

    A few Spectrum game fixes.
  • i'm not sure how to add pics. as far as i know it was uk, was on a Z70833 issue 2 this was on a +2A, if +2b where the end of the run why were they on issue 2 boards and some or all issue 4 are +2A. i'm working on a couple of uk made +2's at the sec i thought they were all taiwan produced but i see they have slightly different motherboards
  • The PCBs didn't change over at the same time as the cases. I suspect they just used +2A cases up until they ran out of them.
    My rubbish website including the redrawn Amstrad schematics and the new home of the Sinclair FAQ wiki.
  • mark8bit wrote: »
    i'm not sure how to add pics.
    You have to upload them to a photo/picture sharing site, then link to them by putting the URL in URL tags (use the ‘chain link’ button above the edit box) or if the URL points directly to a picture file, use the IMG tags (use the square ‘photo frame’ button above the edit box).

    Amstrad produced various boards for the black +2. The first case was labelled +2A and used the same board as the +3, but without the disk drive circuitry. But not many numbers of these fitted in +2A cases appears to have made it into the wild, most being used to make +3 machines (obviously with the disk drive circuitry fitted). Instead most +2A cases have the board that is often called the +2B board. It gets called this, because this is what is in the +2B case.

    We know that some +2 grey machines were manufactured in the U.K. and some were manufactured in Taiwan.

    It would not surprise me if the +2A, +2B, +3 and the less common +3B were manufactured in various countries using whichever parts were the cheapest at the time.

    It’s also possible that there were supply problems with ASTEC made modulators.

    Mark
  • 1024MAK wrote: »
    It gets called this, because this is what is in the +2B case.
    More that it's the circuit described in the +2B service manual.
    My rubbish website including the redrawn Amstrad schematics and the new home of the Sinclair FAQ wiki.
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