Hexbus To Dockbus Issues

[mutantcamel1979]

Hi - I've purchased 2 hexbus to dockbus adapters with the aim to use some dockbus peripherals with my CC40's. 

 

I have tried 3 peripherals with both adapters, The TI PC Interface, TI Printer 324 and the Mechantronic Quickdisk-02 and each time I get the I/O Error 255.

 

I am using a male to female dupoint cable on the dockbus side of the adapter to connect it to the peripherals. 

 

Annoyingly I did get the printer to work once and the PC Interface seemed to detect it was plugged in, but just froze when I tried to load or save a program, until I removed the hexbus cable. 

 

I have tried multiple dupoint and hexbus cables on multiple systems, but I'm not getting anywhere.

 

All peripherals are working fine with my TI-74. 

 

I can take a photo to show how I've attached things. 

 

Any help would be appreciated!

 

 

 

Edited August 2 by mutantcamel1979

[brain]

A photo might be nice, of all 4 connections.  The adapter is a passive item, so I am usure what might be it's issue.  I'd also inspect the solder joints, as maybe the assembler missed something.

 

Jim

[mutantcamel1979]

So I gathered it might be a connection issue rather the adapters being faulty. 

 

I got the PC-324 Printer working ok, so I decided to plug both the PC Interface and Quick Disk into the back of the printer to access them that way. I think it was designed for the CI-7 Cassette Interface, but thought it might work.

 

The PC Interface I got working this way, which is great.

 

The Quick Disk still doesn't work however and with it plugged into the back of the printer, it also disables the printer for some strange reason.

 

The printer works fine using a TI74 though and the Quick Disk.

 

Edited August 4 by mutantcamel1979

[mutantcamel1979]

**Update** I also tried connecting the peripherals without a dupoint cable, plugging directly into the adapter. The PC-324 Printer worked without one, but the PC Interface did not. The Quick Disk did the same thing as above.

 

I'm at a total loss with the Quick Disk and how to get it to work on the CC40.

 

Is there anyone out there with a TI74 Quick Disk who has had the same problems I wonder?

 

 

 

 

 

 

 

[KlausO]

I also tried to connect a Mechantronic Quickdisk-02 to a CC40 and initially always got I/O Error 255. Then pengels advised me to check the voltage on all lines of the Quickdisk-02 with a meter and I measured only 0.5 volts. The floppy drive has no pull-up resistors internally, as all other devices do. This doesn't seem to be a problem for the data lines, but there is the reset line, which is usually kept at 5V by a TI-74 that is switched on.

My Quickdisk-02 needs this 5V on the reset line, i.e. the connection directly next to GND. Since the CC40 does not provide 5 volts, I connected 4 batteries to 6V together, connected the anode of a small diode to the positive pole and its cathode with a 10k ohm resistor. The other end of the resistor is then connected to the reset line and the negative pole of the battery to GND. Thus, the reset line is pulled up to 3.7 volts and the Quickdisk-02 can be used normally from the CC40.

 

 4 batteries of 1.5 volts each   ==> -|>|- a diode to lower the voltage  ==> a 10k Ohm Pull-Up-Resistor  ==> Reset-line 
(or 2 button cells of 3 volts each)

 

How this used to work without an additional battery is a problem to me. Maybe later (or earlier?) built Quickdisk-02 have built-in pull-up resistors after all.

[KlausO]

At arcadeshopper.com I ordered two "dockbus to hexbus adapters" and convert one with the help of a battery holder for two CR2032, a diode and a resistor to an adapter only for the Quickdisk drive. I use a standard diode of type 1N914 and a normal 10k Ohm resistor, the exact value is not so important, between 8 and 20 kOhm everything should work. I still had one with 5 color rings there: brown, black, black, red and brown. That means 10k Ohm with 1% tolerance.
 

Did you notice that the red LED at the front of the Quickdisk drive lights up exactly when a connected TI-74 is switched on? As soon as you turn off the computer, the LED goes off. I think the floppy drive uses the reset line to detect if the connected computer is on and then wakes up from a power saving mode. That's why it doesn't respond to the CC-40, the LED stays off and it "sleeps". As soon as the reset line is set to high the LED turns on, that's what the batterie, diode and resistor are for.
 

[mutantcamel1979]

The finished adapter looks great Klaus, very professional job.

 

I seriously need to practice soldering to get results like that!

 

I wonder how many TI74 Quickdisk exist in the wild, but it's great that you have found a solution to my problem 🙂

Edited September 22 by mutantcamel1979

[+Ksarul]

6 hours ago, mutantcamel1979 said:

I wonder how many TI74 Quickdisk exist in the wild, but it's great that you have found a solution to my problem 🙂

All of the Mechatronic Quick Disks are relatively rare in the wild. I don't think I've seen/heard of more than about 20 of them (all variants combined) in the last 20 years.

[+OLD CS1]

11 hours ago, Ksarul said:

All of the Mechatronic Quick Disks are relatively rare in the wild.

And beautiful devices.

On 9/15/2023 at 12:46 PM, KlausO said:

 

 

[mutantcamel1979]

Shame so few exist, the perfect old school storage solution for both the 74 and CC40. If so they might be more demand for this adapter to be made up and sold. If only TI released something like this themselves, things might have been different and these little computers would receive more recognition and love. 

[KlausO]

The TI-95 does not have commands to save and load programs via the pc-interface. Now there is QFL on this page:

http://pengels.bplaced.net/index.php/tiif

I have adapted QFL so that it uses the quickdisk-drive instead of the pc-interface. With this QDM you can save programs to disk and load them again. Two utilities for displaying the directory (DIR) and formatting new disks (FRM) are also available. Is anyone interested in the programs QDM, DIR and FRM?

[+Ksarul]

5 hours ago, KlausO said:

The TI-95 does not have commands to save and load programs via the pc-interface. Now there is QFL on this page:

http://pengels.bplaced.net/index.php/tiif

I have adapted QFL so that it uses the quickdisk-drive instead of the pc-interface. With this QDM you can save programs to disk and load them again. Two utilities for displaying the directory (DIR) and formatting new disks (FRM) are also available. Is anyone interested in the programs QDM, DIR and FRM?

I would be interested in those utilities, and I suspect there are at least a dozen others here that would use them too.

[KlausO]

Appendix B of the TI-95 Programming Guide describes the CIO function. Page B-6 lists the hex codes of the I/O commandos. The hex code 0D tells the Quickdisk drive to format the inserted floppy disk. The drive has the device number 8. This is the small program FRM to send the format-commando to the Quickdisk drive:

0000 SF 15 CLR `format QD?` Y/N GTL JA
0022 CLR 
0024 DFN CLR 
0025 HLT 
0026 LBL JA 
0029   DFN CLR 
0031   UNF 080D00000018 STO B 0000E73F STO C DEC CIO B RTN
0060   

 

The DIR program is much more extensive, but it's basically just a bunch of different CIO instructions. QDM is quite large and, like QFL, also requires the data file +PC in the MEM area.

The attached zip file contains the source code of the three programs. The file extension is K95 as it uses TIIF2, but they are ASCII files that can be viewed with any editor. 

There are three files with the extension B95, which are intended for transfer to a TI-95.

 

QDM.zip