TI99/4A accessing a Commodore 1541

[TVsHasselhoff]

On 2/27/2023 at 12:18 PM, atrax27407 said:

I use (and have for years) PC-TRANSFER to move files from a PC to a TI. I use a USB 720/1.44 3.5" drive that I format on the PC to 720 sectors with a small program. Copy the files to it and stuff it into my TI with a DSDD BWG controller (it will also work with a CorComp), select the appropriate conversion file, and go from there. BTW, the 720K maximum is not documented in the PC-TRANSFER docs.

 

My TI drives are 3.5" drives as well. 

Does the 3.5 drive option for the TI PEB only work with the CorComp or BWG (not sure which one this is) controller, or will the standard 1240 controller card (SS/SD) work with the 3.5 drive, too? 

 

 

[+arcadeshopper]

19 hours ago, TVsHasselhoff said:

Does the 3.5 drive option for the TI PEB only work with the CorComp or BWG (not sure which one this is) controller, or will the standard 1240 controller card (SS/SD) work with the 3.5 drive, too? 

 

 

 

you can use them but only as the format your controller supports..  functionally they will operate as any shugart drive interface.. but for instance a TI controller will only get you DSSD 40 track (180k) but if you modify the roms you can do 80 track on a 3.5" drive and get DSSD 80 track (360k) storage..   with a corcomp you get DSDD (360k) and myarc FDC or HFDC the same, but there's also a 80 track rom for the Myarc FDC controller to get you 80 track DS/DD (720k) .. you'll never get HD on a 4/A with any controller.. on the Geneve we can get 1.44/HD with a Myarc HFDC only.   you probably need to use 720k disks (DS/DD) with the 4/a, but hd disks CAN be used with the hd hole covered. they just may or may not work in 720k drives later.. 

[TVsHasselhoff]

12 hours ago, arcadeshopper said:

 

you can use them but only as the format your controller supports..  functionally they will operate as any shugart drive interface.. but for instance a TI controller will only get you DSSD 40 track (180k) but if you modify the roms you can do 80 track on a 3.5" drive and get DSSD 80 track (360k) storage..   with a corcomp you get DSDD (360k) and myarc FDC or HFDC the same, but there's also a 80 track rom for the Myarc FDC controller to get you 80 track DS/DD (720k) .. you'll never get HD on a 4/A with any controller.. on the Geneve we can get 1.44/HD with a Myarc HFDC only.   you probably need to use 720k disks (DS/DD) with the 4/a, but hd disks CAN be used with the hd hole covered. they just may or may not work in 720k drives later.. 

I don't want to derail the original topic with this info, unless he feels this is a better alternative for him that utilzing the 1541.  This is good information to know since I'd like to get another drive for my setup, either integrated into the PEB or as a standalone drive.

[donlafferty]

6 minutes ago, TVsHasselhoff said:

I don't want to derail the original topic with this info, unless he feels this is a better alternative for him that utilzing the 1541.  This is good information to know since I'd like to get another drive for my setup, either integrated into the PEB or as a standalone drive.

Not a problem to me. I've already decided it would be way more work than I wanted to do. But I am interested in the things others are saying.

[wierd_w]

In theory, if you made a DSR for it and have some kind of RS232 (or use the strangecart in a novel way), one COULD slave a TPDD on. 

 

(If you turned the baud rate waaaaaay down, you could maybe use the cassette interface, by abusing motor-on as CTS ? (DTR would be harder, but 'no flow control' is/was a thing) It would need an amplifier though.)

 

The API to communicate with the drive is very simplistic, so it would be easy enough to do, but very little else (aside from knitting machines) uses the disk format. (And you only get high level access, not low level block access.)

 

It also wouldnt hold much.

 

It's just an 'in theory' thing.

 

TIPI and NanoPEB are just better options.

 

In hindsight though, a DSR GROM cartridge with an analog amplifier/stepdown bridge on the cassette cable might have been a plausible aftermarket product to work with a vintage TPDD.

 

(Put a DAC between the serial based TPDD and the analog FSK ti cassette interface. Use cassette motor-on 1 to tell the analog bridge that the TI is ready to get a short FSK based burst, and cassette motor-on 2 to tell it is going to transmit a burst.  Inside the bridge is a buffer chip and a serial uart bound to a hardware FSK tone generator and interpreter.  It provides a 'safe' sink for serial data at 300bps to be communicated by, and generates CTS/DTR based on buffer fullness.  Manage the interface directly by the CRU.)

 

Is cassette interface full duplex?

 

 

Edited March 3, 2023 by wierd_w

[+OLD CS1]

@wierd_w I look forward to the blog of your progress.

[+Ksarul]

On 3/1/2023 at 4:05 PM, TVsHasselhoff said:

Does the 3.5 drive option for the TI PEB only work with the CorComp or BWG (not sure which one this is) controller, or will the standard 1240 controller card (SS/SD) work with the 3.5 drive, too? 

 

 

A weird note on PC-Transfer and moving files between the TI and a PC. The program was originally designed to run with a CorComp DSDD controller (with 360K disks), but the last update to the program allowed 720K disks as well. There are several controllers out there that PC-Transfer recognizes as CorComp, even though they are not. The BwG controller (BeckerWinterGlaab) from the System99 user's group in Germany is likely the most widespread of the alternates (there are about 150 of them, mostly in Europe). The Atronic DSDD controller card (a commercial product, also from Germany) came in the form of a PEB card (somewhat rare, although I do have one) and as part of a sidecar system called the CPS-99 that had memory, RS-232, disk controller, and drive(s) in one neat package (less rare than the PEB card, but still very HTF). The last one that it should work with would be the Regle de Calcul sidecar controller from France, as it is also a CorComp derivative (thanks for making me aware of this one @fabrice montupet). Of all of these, the controller from CorComp is by far the most common one.

 

When using the TI PHP1240 controller, you are generally limited to 180K (DSSD) storage on a 40-track drive. That limit is not absolute, however, as there are variants of the card's EPROM that allow use of 80-track drives too. The key is that those drives "should" be 720K native format drives (these exist as both 5.25 (Teac FD-55F, for one) and 3.5 inch drives). It is generally a good idea to totally avoid any HD 5.25 drives, as you will have problems, although the HD 3.5 drives seem to give fewer issues. When using 80-track drives, disk capacity on a TI controller increases to 360K in DSSD mode.

 

There are also other controllers out there, but this should help with the types that have shown up in this thread so far.