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Thread: KayPlus ROM questions

  1. #1
    Join Date
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    Default KayPlus ROM questions

    I ran across a discussion of ROM releases for the Kaypro (http://www.retroarchive.org/maslin/r...pro/index.html) and discovered that in addition to at least four different versions published by Kaypro there were at least three other ROM codes released by other parties: MicroCornucopia, Advent and KayPlus. MICROCODE Consulting still maintains a web site (http://www.microcodeconsulting.com/z80/kayplus.htm) and has released their product, KayPlus, to the public domain. Along with two versions of the ROM code, to accommodate different Kaypro board revisions, they also have a suite of utilities for the Kaypro and quite usable documentation.

    Page 58 of the documentation goes into identification of Kaypro motherboard versions (in order to select the proper version of the ROM code), and their comments were both enlightening and confusing. Specifically, referring to the 81-240 board, they state: "This board is identical to the Kaypro II, except that it has two jumpers, J1 and J2, labeled on the board next to U47**. These allow either a 2732 or a 2716 ROM to be installed."

    I have two such boards and on each J1 and J2 are connected to one another by a trace or surface wire on the top side of the board. There are no terminals to be jumped, as it were. Does anyone know how this arrangement works; i.e. enables the use of one EPROM or the other?

    The docs go on to say: "This board is fully capable of running double-sided disk drives... This board may be found in Kaypro IIs and 4s." I have a II and a IV (also called a 4/83) both with the same layout, ROMs and version number. From this I infer that all I need to do to add double-sided drives to the II is to add double-sided drives to replace the single-sided drives. Has anybody been down this road? What am I missing?

    Thank you for your replies.

    -CH-

    **U47=BIOS EEPROM

  2. #2
    Join Date
    May 2012
    Location
    Auckland, New Zealand
    Posts
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    Quote Originally Posted by clh333 View Post
    Page 58 of the documentation goes into identification of Kaypro motherboard versions (in order to select the proper version of the ROM code), and their comments were both enlightening and confusing. Specifically, referring to the 81-240 board, they state: "This board is identical to the Kaypro II, except that it has two jumpers, J1 and J2, labeled on the board next to U47**. These allow either a 2732 or a 2716 ROM to be installed."

    I have two such boards and on each J1 and J2 are connected to one another by a trace or surface wire on the top side of the board. There are no terminals to be jumped, as it were. Does anyone know how this arrangement works; i.e. enables the use of one EPROM or the other?
    I may have some answers for you on this which I discovered when using the Advent ROM on the Kaypro II with the FreHD (http://www.quicktrip.co.nz/jaqblog/home/94-kprofrehd3)

    The Kaypro II has a 2716 EPROM v 2732 on the 4/83.

    Pin 21 on the 2716 is VPP but on the 2732 it is A11. The Kaypro II PCB pulls pin 21 to VCC.

    I didn't use the jumper (can't actually remember if it is on my board) but very likely it connects Pin 21 to +5v.

    If you want to use one of the third party ROMs (I find that the Advent '83 version works well for the Kaypro II and 4/83) then you will need to ensure Pin 21 connects to A11. Otherwise the 2732 is pin compatible with the 2716.

    Hope that helps.
    SBC6120 / PDP11 + VAX / TRS-80 / Kaypro / Northstar / Home Brew Z80 / BBC / Amstrad / Commodore
    http://www.quicktrip.co.nz/jaqblog

  3. #3
    Join Date
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    Quote Originally Posted by jaquinn View Post
    I may have some answers for you on this which I discovered when using the Advent ROM on the Kaypro II with the FreHD (http://www.quicktrip.co.nz/jaqblog/home/94-kprofrehd3)
    Thank you for your response. In addition to answering my primary question you have opened the door to new possibilities previously unknown to me. I will investigate the FreHD further. (And a tip of the hat to Frédéric Vecoven!)

    -CH-

  4. #4
    Join Date
    May 2012
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    Auckland, New Zealand
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    There are a series of posts on my Blog about the FreHD and the Kaypro 4/83 and Kaypro II.

    http://www.quicktrip.co.nz/jaqblog/c...rdering=newest

    I notice that this doesn't cover the later updates that use the Advent '83 ROM so will add it to the "todo" list. I don't have an '84 Kaypro so haven't the FreHD with that version.
    SBC6120 / PDP11 + VAX / TRS-80 / Kaypro / Northstar / Home Brew Z80 / BBC / Amstrad / Commodore
    http://www.quicktrip.co.nz/jaqblog

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