TRS-80 Model 1 and the HXC SD FW Floppy Drive Emulator

[Audronic]

Hi Jeff or any Model 1 TRs-80 Users

I have an SD FW Floppy Drive Emulator.

My Hardware for these tests are :-

1 Floppy Drive 40 Track Double sided 5 1/4 "
1 SD FW Floppy Drive Emulator.
These are in the same box using the same power supply.
I have Wired a switch to change the drives over from 0 to 1 and from 1 to 0,
So that I can Boot from either.

I have tried these tests with Ldos5.3.1, Dosplus 3.5, Newdos 80 V2 and 2.5, Multidos 1.6.
And they all exibit the same concern. ???

I am using it on a System-80 (Video Genie) Trs-80 Model 1 clone and on a Trs-80 Model 1.
If I use the emulator on the System-80 The emulator works perfectly, using single sided single density -jv3.hfe files
and Double Sided Single density -JV3.hfe files.
Both drives work as Normal in either direction of the switch.

BUT

If i use it on the Model 1 It wont boot ?.
BUT if I flip the volume to the other side It will boot ?.
But only Single sided volumes NOT Double sided.

The Floppy still works on Single or Double sided disks. As either Drive 0 or drive 1.

Can you help

Ray

[Audronic]

Hi All

Just a followup :-

I have just put the HXC and the Floppy on my TRS-80 Model 4 and it works perfectly.

It works on the System-80 and the Model 4 BUT not on the Model 1 ???

Ray

[Jeff]

Hi All

Just a followup :-

I have just put the HXC and the Floppy on my TRS-80 Model 4 and it works perfectly.

It works on the System-80 and the Model 4 BUT not on the Model 1 ???

Ray

It does since this was tested by someone else.
Can you share your hfe & dsk files?

[Audronic]

Hi Jeff


The link to my Model 1 and Model 3 files.

https://www.dropbox.com/sh/hwwjwrytie81 ... IYbzGOpPPa

Is there an answer to the TRs-80 Model 1 Problem Please.

PS :- The second comment was just to confirm that the emulator would
work on the Model 4 TRS-80.

Ray

[Jeff]

BUT

If i use it on the Model 1 It wont boot ?.
BUT if I flip the volume to the other side It will boot ?.

Is it a question or a fact ?

What is displayed on the HxC LCD ?

[Audronic]

Hi Jeff

(Is it a question or a fact ?)

It won't boot in its Normal mode at power up (after Reset of computer).

Photo's in Link :-

https://www.dropbox.com/sh/34zmk5cf62jn ... IH16X_09qa

Ray



[Jeff]

Hi Jeff

(Is it a question or a fact ?)

It won't boot in its Normal mode at power up (after Reset of computer).

Photo's in Link :-

https://www.dropbox.com/sh/34zmk5cf62jn ... IH16X_09qa

Ray



I don't understand this sentence :

>BUT if I flip the volume to the other side It will boot ?.

So you manage to make it work with some parameter change or not ?

[Audronic]

Hi Jeff

If I hold the Middle Button down it will ask choose a file, Press middle button, Volume Mounts.
If i then hold the Middle button down for some seconds it will ask:-
(1) change drive.
(2) if i press the left button it will ask to Flip Disk
(3) I then press the Middle button, the disk is flipped.
(4) it will then ask to choose a File if i press the middle button it will mount that file.

If i then Boot the computer then the single sided volume will Boot.

Yours Ray

[Jeff]

Hi Jeff

If I hold the Middle Button down it will ask choose a file, Press middle button, Volume Mounts.
If i then hold the Middle button down for some seconds it will ask:-
(1) change drive.
(2) if i press the left button it will ask to Flip Disk
(3) I then press the Middle button, the disk is flipped.
(4) it will then ask to choose a File if i press the middle button it will mount that file.

If i then Boot the computer then the single sided volume will Boot.

Yours Ray

ok Thanks, i got the whole picture now and this make sense regarding your pictures :
For some reasons the the TRS 80 Model 1 try to read the Side 1 (S:1) and that's why you have to "flip" the disk.
The TRS80 Model 1 disk drives was single sided only ?

[Audronic]

Hi Jeff

Yes originally they were Single Sided.

In my setup i have the HxC and a Double sided Teac FG55BR on the same floppy cable.

The HxC has the Problem, The floppy works perfectly as a Double sided drive.
I am able to Boot with a Double Sided or Single sided floppy.

I have changed Cables etc

The pull-ups (terminators) in the Teac FG55BR are 1000 Ohms the same as in the HxC.

The document Here :- https://www.dropbox.com/sh/fv1a5exrvgex ... FLcR1FUVHa
has some of my thoughts.
I have the OLD expansion which uses 7438's as drivers.

Yours Ray

[Jeff]

lol : It seems that the HeadSelect signal (32) was used as DS3 signal on this computer.
Disconnect the signal n°32 (/SIDE1 Head Select) from the HxC and all will be fine.


BTW : Which switch/jumper setting are you using ?

[Audronic]

Hi Jeff

lol : It seems that the HeadSelect signal (32) was used as DS3 signal on this computer.
Disconnect the signal n°32 (/SIDE1 Head Select) from the HxC and all will be fine.

BTW : Which switch/jumper setting are you using ?

If i remove the head select signal then i am only able to use Single sided Volumes.

I have ID0A only turned on During the tests.

-=============-

I had a thought over night that if i load the pin32 with say 1000 Ohm or 470 ohm in the TRS-80 interface to shift the Voltage level when LOW,
that this may help. The TRS-80 Model1 normally works with a 150 ohm load on pin 32.
I have looked at the Specifications for the Pic chip and the Max Load is 220 Ohms (approx) for this line.

I will try this first and get back to you.

Yours Ray

[Audronic]

Hi Jeff

I just opened the Expansion interface for the TRS-80 Model 1 and Found that they had joined pin 32 and 34 together.
So your Floppy READY signal was coming back on pin 34 and forcing the pin 32 LOW Grrrrrr.

I have got an AXE :: }} and removed the shorting link and will now test it without adjusting terminations.

This is only for the Early version Expansion Interface Board ONLY.
The Later (Redesigned) Expansion Interface the pins are NOT connected together.

https://www.dropbox.com/s/suhnseso7t7yd1f/Pin32-34.JPG

I will inform you of the progress.

Yours Ray

[Audronic]

Hi Jeff

Trs-80 Model 1and the HXC

The problem is resolved , remove the bridge between pins 32 and 34 and it works PERFECTLY.

If you have helpful notes for specific Computers that connect to the HxC please include this fix.

Thanks for all your support and patience. I OWE you a Beer or Meal if you are ever DownUnder.

Yours Ray

[Jeff]

Quite strange this short. So the ready signal isn't used by this machine ?
In this case you have just to set the pin 34 to HIGH into the embedded HxC menu. No need to cut the track.