8" floppy project

[Tony Duell]

> > > comany that has produced and PUBLICLY sold as many service and parts
> > > manuals as IBM has for the PC AND ALL OF IT'S ACCESSORIES AND
> > > PERIPHERALS.
> > 
> (*trimmed*)
> > IBM service manuals (at least the Hardware Maintenance and Service
> > manual i have for my PC/AT) are boardswapper guides. They're pretty
> > useless now, they are totally useless when there are no more boards to
> > swap.
> > 
> 
> The IBM PC/XT and PC/AT Technical Reference manuals include complete
> schematics, and they include complete, commented source code listings

I can't argue with that. I have them for the PC, PC/XT, PC/AT and PCjr, 
along with _some_ of the options/adapters manuals. Full schematics (but 
not of the PSU or the EGA monitor for some reason), BIOS source, etc.

The 'Hardware Interface Technical Reference' for the PS/2 machines is 
nowhere near as good. It's got pinouts and some details of the custom 
chips, but no schematics. 

> for the BIOS.  Similar documents exist for some of the 'clone' machines,
> i.e. the Compaq Deskpro and the AT&T 6300.
> 
> This is sadly not the case for most of the modern (modern meaning
> anything newer than the XT/AT generations) 'PeeCee' hardware, but it is

Hence my origianl comment that modern PCs are difficult to maintain.

> the case with the earlier systems.  It's definitely the case with the
> machines from the era of most of the other hardware you listed, i.e. the
> Apple II, HP71B.

The suprise is the HP75C. There is a service manual for it, and AFAIK it 
was available to anyone who wanted to order it. The supported repair 
method is board-swapping (keyboard/top case, CPU board, memory board, 
display IIRC). However, the manual includes full schsmatics and PCB 
layouts and an _excellent_ theory-of-operation section.

The 75C ROM listing exists too, but it wasn't an official HP product. It 
was sent to PPC (User group) under the NOMAS scheme (NOt MAnufacturer 
Suported -- you could read/copy the listing, but you couldn't bother HP's 
technical support about it). It is suprisingly hard to find now.

> 
> Times have changed, but times have changed all over.

Not round here they haven't :-)

-tony