Tony's kit, was: Re: USB Stuff

[Tony Duell]

> 
> Tony Duell wrote:
> 
> > Actually it doesn't. I am looking at a monochrome green screen at the 
> > moment. OK, I do have colour monitors around here....
> 
> I know I've asked this before but I don't recall the answer.  What 
> exactly *do* you use to connect to the Internet?

I am sure I described it a couple of weeks ago here, and I've not 
downgraded [1] since then

[1] That is, to sowmthing without schematics.

OK, here you are again : 

A much-hacked IBM PC/AT (8MHz system board). The mainboard has a 486 
kludgeboard in the 80286 socket. I've added a couple of EPROMs and a bit of 
logic to overlay the last 8K of the bios, so I could modify the hard disk 
parameter table.

Thers's 512K on the mainabord. Abother I/O card adds the 128K to bring it 
up to 640K + anothet 1.5M extended memory + 2 serial ports (16550s, of 
course, I want to give this processor all the help it can get) and a 
parallel port.  Another expansion board started off life as an IBM 128K 
card. I figured out it could be populated with 2 rows of 256K bit DRAMs, 
and a bit of extra logic, and turned it into a 1M card. Although all the 
traces for this were there, etched on the board, I can't find any mention 
of this in the TechRef. And another board adds a further 2M of RAM.

There's an original IBM MDA board linked to a 5151 greenscreen monitor. 
And a Colorgraph+ (Enhanced CGA card, with enough RAM for 640*200 in 8 
colours, pity nothing supports it). That's linked to an NEC monitor that 
was used with an Apple ][, which I modifed to add the intensity line.

The disk controller is an early IDE card, a few TTL parts, a couple of 
PALs and a floppy controller chip. I added a daughterboard containing a 
couple more TTL chips to flash the frontpanel drive LED when the hard 
disk was accessed. It's linked to the original IBM 1.2M drive and a Teac 
1.44m 3.5" drive. And to a 1.3G IDE winchester.

TO actually connect to the phoneline, I've got an old USR Sportster 14K4 
modem. That, and the hard drive, are the only parts of the system I don't 
have full schemaitcs for.

-tony