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Re: LocoLink: Unable to Load PCW Program

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On Wednesday, January 6, 2016 at 11:00:25 PM UTC, Geoff Barnard wrote:

> Else we'll need to pester John Elliott - he's the EXPERT.   I keep pestering 
> him, a lot of what I'm writing here is the result of things I've learned 
> from him, in connection with my getting my 5.25 working as A:, and re my use 
> of his Joyce emulator system.

Somebody called?

Glancing over this thread I can see a certain amount of confusion, so here's the state of play as I understand it.

* First-generation PCWs (8256,8512,9512) have 3" drives and use .EMS files.
* Second-generation PCWs (9256,9512+,10) have 3.5" drives and use .EMT files.

Aftermarket 3.5" drives for first-generation PCWs were supplied with updated versions of CP/M and LocoScript. These would include .FIB files to inform the operating system about the nonstandard drive configurations on these computers. CP/M usually boots without them, but LocoScript doesn't -- it displays an 'Incompatible version' error at boot.

On a PCW 8256/8512 with a 3.5" floppy drive, it's possible to run the original versions of CP/M / LocoScript (intended for a 3" drive), as long as you don't break its illusion that drive A: is 3" 180k. That means formatting 3.5" discs as 180k and wasting 75% of the space on them. The easiest way to do this with a UNIX box is to use dsktrans to write a 180k disc image onto the disc. (Using dd is more complicated because of the order in which it accesses tracks; dsktrans avoids the problem by using physical cylinder/head/sector addresses).

dsktrans is part of libdsk <http://www.seasip.info/Unix/LibDsk/>. It's what I'd recommend to write a disc image to floppy  (dsktrans -otype floppy file.dsk /dev/fd0) or convert a .dsk to a raw 'dd'-style disc image (dsktrans -otype raw file.dsk file.ufi) or vice versa (dsktrans -otype dsk file.ufi file.dsk)

To get files in and out of PCW-format disc images, I also recommend cpmtools <http://www.moria.de/~michael/cpmtools/>. If built against libdsk, it can access files in DSK-format disc images; if not, only 'dd'-style.

Given that the OP has LLINK202 as an EMS file, my inclination would be to start with a disc image of the original 180k PCW8256 boot floppy, use cpmtools to erase its EMS file and inject LLINK202.EMS, and then write the result to a 3.5" floppy and see if it boots.

One other annoying thing: once PCW CP/M has accessed a 720k 3.5" disc, it won't recognise 180k 3.5" discs in that drive. This is because it thinks 180k discs need to be double-stepped in a 720k drive; this is true for 3" discs but not 3.5". It's possible to get round this by setting the 'double track' bit and the freeze flag in the XDPB for that drive, but this post is long enough as it is.

-- 
John Elliott

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LocoLink: Unable to Load PCW Program Andrew Ferguson <andrewferguson500@gmail.com> - 2016-01-02 06:14 -0800
  Re: LocoLink: Unable to Load PCW Program Enrique Garcia <enriquegg@gmail.com> - 2016-01-03 00:40 -0800
  Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-03 15:26 +0000
    Re: LocoLink: Unable to Load PCW Program Andrew Ferguson <andrewferguson500@gmail.com> - 2016-01-04 10:32 -0800
      Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-04 23:17 +0000
      Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-04 23:50 +0000
      Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-05 00:37 +0000
      Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-05 17:05 +0000
        Re: LocoLink: Unable to Load PCW Program Andrew Ferguson <andrewferguson500@gmail.com> - 2016-01-06 08:23 -0800
          Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-06 18:39 +0000
            Re: LocoLink: Unable to Load PCW Program Andrew Ferguson <andrewferguson500@gmail.com> - 2016-01-06 12:59 -0800
              Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-06 23:00 +0000
                Re: LocoLink: Unable to Load PCW Program Floppy Software <floppysoftware@gmail.com> - 2016-01-07 11:27 -0800
                Re: LocoLink: Unable to Load PCW Program Andrew Ferguson <andrewferguson500@gmail.com> - 2016-01-07 13:11 -0800
                Re: LocoLink: Unable to Load PCW Program Matthew Phillips <spam2011m@yahoo.co.uk> - 2016-01-07 22:45 +0000
                Re: LocoLink: Unable to Load PCW Program seasip.webmaster@gmail.com - 2016-01-07 15:17 -0800
                Re: LocoLink: Unable to Load PCW Program "Geoff Barnard" <geoff@jgb17.co.uk> - 2016-01-08 00:42 +0000
                Re: LocoLink: Unable to Load PCW Program seasip.webmaster@gmail.com - 2016-01-08 06:23 -0800

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