99er Forums

Hi all! I bought a PEB about a year ago without a disk drive. Now I have bought a new old stock PHP-1250 disk drive, which I have fitted into the PEB, but I cannot access it properly. When I try to initialize a floppy using the disk manager module, I receive a disk error 21 (seek error) after providing the disk number. The drive spins up though and the LED lights up. First I thought that it might be a problem with the flex cable, because the connection to the interface card had broke. As the plastic connector had cracked, I desoldered it and soldered the flex cable directly to the card and put some hot glue on it to hold it steady. But after trying again I still get the same error. The floppy disks that I have been using are original commodore 5.25" disks (suitable for C64). They are labeled 48tpi 1d.

The PEB also contains a RS232 card which I seem to be able to access. I have tried with the following and it lights up when I try send a listing to the port:

Code: Select all

open #1:"RS232.ES"
list "RS232"
close #1


I have also cleaned all connectors with a electrical contact cleaner. Does any one have a tip how to proceed?

Thanks!

I would check the cable between the disk controller card and the drive itself. You may have a loose connector or a pinched wire somewhere. Do you have another physical drive to test with? All other problems will lead to that as a possible problem point. From your description, the card seems to be good. . .

I have only a couple of full-height 5.25" Micropolis drives, but I do not know the status of these or if they are even compatible with the ti99.

Are there any special requirements on the cable between the drive and the drive controller card? I have a straight cable with a 34 pin connector and two edge connectors. I tried with another cable that was setup in the same way, but the second edge connector had a twist on it. Anyhow, the results were the same, disk error 21 after drive selection and disk error 43 during initialization (using the non-twisted edge connector).

It should be a straight cable for a one drive setup right? Does it matter if there are one or two edge connectors on the cable?

Pretty much any 40-track drive (single or double sided) will work with the TI. The last drive in the sequence always have to have the termination shunt pack installed. It might also be a good idea to check to see if the drive jumpers are set to hard code it as drive 0--as drives then were usually numbered 0-3 on the drive select jumpers. Don't change any of the other jumpers in that jumper pack with the drive selects, as it will usually cause problems. One last note--a TI does NOT like cables with a twist. You can either disassemble the cable and untwist it (this requires care so as not to destroy the cable) or just use a new connector after removing the twist (better). I hope this helps!