Tandy 1400HD - hard disk not recognized?

[commodorejohn]

So I rescued a Tandy 1400HD laptop from the recycling center yesterday. It's a little dirty but otherwise in good shape, powers on with no problems, and successfully boots into DOS from a generic DOS 3.3 floppy disk. However, it doesn't recognize the hard disk or mount it as a drive that I can format. Looking around a bit, I found a piece of documentation errata stating that DOS hard-disk utilities like FDISK don't work on the 1400HD, so I'm figuring that it has some non-standard method of hard-disk access that vanilla DOS doesn't understand. Is there anywhere I can get a 1400-specific boot-disk image to try with this, or does anybody have some other insight into this?

 

[southbird]

I don't know about the specific access thing, but I would sooner bet on the HDD itself has simply failed. Make sure that it is whirring to life (which should occur shortly after power is applied) and make sure the LED isn't flashing an error code, which I had on an old 1400HD some years ago.

 

[commodorejohn]

Hmm, now that I look at it, the LED is doing a three-flash pattern. Anybody have any troubleshooting documentation for this thing?

 

[southbird]

Hmm, now that I look at it, the LED is doing a three-flash pattern. Anybody have any troubleshooting documentation for this thing?

Hm, that's the same thing I saw on my first 1400HD all those years back. Most likely the HDD is an Alps Electric DRP020A10C. Problem is, have you ever heard of an Alps Electric hard drive? I don't think you have a particularly good chance at finding any documentation on it. I know I was unable to... this is an unfortunate situation of an extremely proprietary HDD (hooked to an internal removable controller) and you probably will not be able to replace it. Although I suppose everyone has been waiting and wondering if an XT IDE could be retrofit into the expansion bus.

 

[pearce_jj]

Although I suppose everyone has been waiting and wondering if an XT IDE could be retrofit into the expansion bus.

Maybe - I'm working on this at the moment. But I really need some more info from a real 1400HD (I only have a 1400FD to work with), since the 'expansion slot' and 'hard disk controller slot' have different connector placement, even though they're on top of each other. Also, I'm not having much luck getting the XTIDE Universal BIOS loaded with the system ROM v1.0.4 (this is in Fake86) - have tried various address placements. According to the 1400LT service manual, all of D segment is available for option ROMs, mind.

 

[pearce_jj]

PCB layout is done. But I'm yet to determine if the 1400 BIOS scans option ROMs - hopefully it will be possible to hack in a straight jmp instruction otherwise (ROM is a socketed 27C256, although on 16KB is used).



(I posted some info on the slots here already.)

 

[ColorComputerStore]

Hey guys, I am in desperate need to know the values of the following caps from a 1400HD PSU
C52
C43
C14
C4
C53

Also R44
R47

My machines components for those can't be read.

Thanks
Carlos