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Tandy 1400 LT Gotek

Hawkeye0914

Experienced Member
Joined
Feb 17, 2019
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54
Location
Dallas, TX
In one of the 8 Bit Guy videos, he is trying to get a Gotek to work on a Tandy 1400 LT. I have been working on mine for hours today without getting it to use the drive, and now none of the internal floppies work (Thankfully it still uses the external 5.25 inch drive I have). I have the Flash Floppy firmware on it, so it should work as a 720k drive. I have used it in my 5150 without any issues. I have tried all kinds of jumper settings but none of them seem to work. Anyone have any luck with these?
 
I got the gotek to read. It boots and everything. I used the 8 Bit Guys diagram with a slight modification. The only problem now is that I cannot access the B drive. It trys to access both drives at the same time.

EDIT: After switching the jumper from S0 to S1 on the Gotek, and switching the dip switch from 1 to 0 on the floppy drive, I can boot DOS from the Floppy and access files on the Gotek. It seems the Gotek is not performing correctly as drive 0 for some reason.

PZqBE2t.jpg
 

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Something weird I noticed, when booting MS Ramdrive is assigned to D when booting from the Gotek. I checked, and the Gotek can be accessed from either the A drive or the C drive. Anyone know why its not being interpreted correctly?
 
The Gotek doesn't do two drives, without a modification. Someplace on the web, as I recall, is a drawing with some wiring and a couple of diodes. to deal with two drives.
Dwight
 
The Gotek doesn't do two drives, without a modification. Someplace on the web, as I recall, is a drawing with some wiring and a couple of diodes. to deal with two drives.
Dwight

The strange thing is, it works fine when I set the the actual floppy drive to A: (0) and the gotek to B: (1). When the gotek is set to A: (0) I can get the contents of the gotek at A:, B:, and C:
 
Hawkeye0914,
I'm thinking that the Floppy Signals are really as show here;
Code:
FDC Controller		PC-AT Style Controller						Based on TEAC FD235HF 

Sig Name		Sig     Sig. Name						Sig Name        Sig    Ground 

Spare 			06      Drive Select D -------------------->>--------------	Drive Select 3	06	05 
Index 			08      Index -----------------------------<<--------------	Index		08	07 
Select 0		10      Drive Select A -------------------->>--------------	Drive Select 0	10	09 
Select 1		12      Drive Select B -------------------->>--------------	Drive Select 1	12	11 
Spare 			14      Drive Select C -------------------->>--------------	Drive Select 2	14	13 
Motor Enable		16      Motor Enable A&B ------------------>>--------------	Motor Enable 	16	15

So, your Tandy 1400 Pin 10 Motor ON should go to Pins 16 of Drive A (Drive 0) & B (Drive 1).

and
Tandy 1400 Drive Select 0 Pin 4 should go to Floppy Pin 10 (Or GOTEK Pin 10) = Drive 0
Tandy 1400 Drive Select 1 Pin 6 should go to Floppy Pin 12 (Or GOTEK Pin 12) = Drive 1

And the DiskChange/Ready needs to be changed to READY as Per the Floppy & GOTEK.

Larry
 
Hawkeye0914,
I'm thinking that the Floppy Signals are really as show here;
Code:
FDC Controller		PC-AT Style Controller						Based on TEAC FD235HF 

Sig Name		Sig     Sig. Name						Sig Name        Sig    Ground 

Spare 			06      Drive Select D -------------------->>--------------	Drive Select 3	06	05 
Index 			08      Index -----------------------------<<--------------	Index		08	07 
Select 0		10      Drive Select A -------------------->>--------------	Drive Select 0	10	09 
Select 1		12      Drive Select B -------------------->>--------------	Drive Select 1	12	11 
Spare 			14      Drive Select C -------------------->>--------------	Drive Select 2	14	13 
Motor Enable		16      Motor Enable A&B ------------------>>--------------	Motor Enable 	16	15

So, your Tandy 1400 Pin 10 Motor ON should go to Pins 16 of Drive A (Drive 0) & B (Drive 1).

and
Tandy 1400 Drive Select 0 Pin 4 should go to Floppy Pin 10 (Or GOTEK Pin 10) = Drive 0
Tandy 1400 Drive Select 1 Pin 6 should go to Floppy Pin 12 (Or GOTEK Pin 12) = Drive 1

And the DiskChange/Ready needs to be changed to READY as Per the Floppy & GOTEK.

Larry

You are a genius. Everything working now. I will update the diagram and post it. Thank you for your help!
 
hawkeye0914,
But, your Updated Diagram still has one error, and some mis-leading text.

The Tandy 1400 Pin 10 Motor ON should go to Pin 16 of Drive A (Drive 0) & Pin 16 of Drive B (Drive 1).
And the text for the Floppy Pin 16 Should say "Motor ON for Drive 0 & Drive 1".

Also the text for the Floppy Pin 10 Should say "Drive Select 0" and
the text for the Floppy Pin 14 Should say "Drive Select 2".

That will make it correct for a straight through cable, with no twisted 10 through 16 conductors.

Glad you got it working.

Larry
 
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