TI99/4A

HxC Floppy emulator support for all others computers...
Jeff
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Re: TI99/4A

Post by Jeff »

ckoba wrote:I don't know enough about Shugart drives to understand what's different between low-level formatting and a simple byte-write, but clearly the HxC isn't responding the way the TI's 1771 controller expects it to.
The flash write latency. The quantity of data to write is smaller in sector write.
The Transcend sdcards have not a good & constant write latency with small write. (always the case with the floppy emulation)
i recommend the Sandisk Extreme Class 10 SD serie.

Btw, why do you need to format the image ?

Jeff
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Re: TI99/4A

Post by Jeff »


ckoba
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Re: TI99/4A

Post by ckoba »

Jeff wrote:The flash write latency. The quantity of data to write is smaller in sector write.
The Transcend sdcards have not a good & constant write latency with small write. (always the case with the floppy emulation)
i recommend the Sandisk Extreme Class 10 SD serie.
Ah, I see. I'll track down a Sandisk in the next few days and see if that makes a difference. Thanks for that.
Jeff wrote:Btw, why do you need to format the image ?
A format test, with what appears to be a subsequent pattern verify, is the standard (TI "Disk Manager") floppy drive controller diagnostic test. If the format doesn't succeed, the diagnostic test fails.

Jeff
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Re: TI99/4A

Post by Jeff »

ckoba wrote:
A format test, with what appears to be a subsequent pattern verify, is the standard (TI "Disk Manager") floppy drive controller diagnostic test. If the format doesn't succeed, the diagnostic test fails.
Yes. The question is : Does the software wait for the index signal to start the checking ? If it doesn't , for sure this will fail cause of the write latency.

But anyway test this :
https://hxc2001.com/download/floppy_driv ... rmware.zip

ckoba
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Re: TI99/4A

Post by ckoba »

Jeff wrote:The question is : Does the software wait for the index signal to start the checking ? If it doesn't , for sure this will fail cause of the write latency.
*shrug* It might not wait. I don't think I'd be able to disassemble the software, so I can't really say what it's trying to do.
Tried. No joy, same behavior as non-beta firmware.

Anyway, I'll find a Sandisk to test with and report the results. If it works, great, just have to remember that all SD cards are not created equal.

If it doesn't ... well, what's the end goal of the HxC? If it's 100% compatibility with a regular drive, then I'll do whatever tests you need to figure this out (up to and including hooking it up to an oscilloscope -- I don't have a logic analyzer, though).

If the goal is "read and write compatible, not necessarily low-level-format" then that's fine too. One shouldn't need to format an image under normal circumstances anyway, the images should be prepared on a standard machine and converted to .hfe format. Maybe put a small bit in the "compatibility" section of the web page saying "formatting doesn't work on TI, known issue, don't do that".

Jeff
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Re: TI99/4A

Post by Jeff »

As i said there is a Flash write latency, and some machines have a timeout too short and report error, or try to format another track while the previous one still pushed to the Flash memory.
One way to avoid this problem is to embedded lot of RAM memory into the emulator to store the whole image, and write back the image into the Flash as background task when needed. But of course this is not the same price ;) ...
Or just use a fast and good flash media as the Sandisk Extreme.

schmitzi
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Re: TI99/4A

Post by schmitzi »

Hi Ho,

This here is from a friend, and I cannot check my PEB/settings at this moment.
But maybe this problem is "well-known" or so, and you can give the right kick :)

"
Finally got some cables yesterday so I could get my Lotharek drive running as one single drive on my PEB (it is currently the only drive connected to the data cable). Works fine so far in single drive mode, but I wanted to use it as drive 1 and 2, so I set the 2 jumpers as described by Iwantgames above and I also made sure in the Lotharek configuration tool there are 2 drives A and B, which was the default setting anyway.

Whenever I select a disk image now on the Lotharek it is always available on both TI drives 1 and 2. So for example when I select disk image X for drive 1 (called drive A on the Lotharek LCD) and then I switch over to "drive B" on the Lotharek with the middle button and select then disk image Y for drive 2 (=drive B), I always see then disk image Y on both drives 1 and 2. I never could manage to get 2 seperate different disk images in both virtual drives so far.

I checked that with the Disk Manager from the Extended Basic v3.7 cart. I also tried to restart the computer just to make sure the software can see the disk change.

I also tried to connect it to the 2nd plug of the data cable but that didn´t change the behavior. Any idea what I could do wrong here?
"
EDIT:
He has set the jumpers "ID0A and ID1A to ON, all other jumpers to OFF."

[->I think this is the problem, we will see now what happens on ID0A + ID1B :) ]

UPDATE1:
"ID0A and ID1B on and the rest off does not work for me, now I only see drive 1 in Disk Manager. With the settings I had before I saw 2 drives with the same disk in it. Will have to do further experiments"

-->OK hmmmm...but this here should be the "better" setting. Maybe try ID1A and ID2B or so...

UPDATE2:
"Settings ID1A and ID2B did help, thanks! I connected a standard 3,5" floppy and the Lotharek on one single 3,5" floppy data cable with 2 connectors. D. was so kind to send me that cable a long time ago with his RS232 set. With that jumper setting the Lotharek is now DSK1 and DSK3, the standard 3,5" drive is DSK2. That´s a perfect setup, as I can boot into Extended Basic with the Lotharek and if I want I can still use stone age disks. :-) 80 track mod seems to work fine as well, at least from what I have seen on the standard disk drive so far."


-> SOLVED :)

Thanks
schmitzi

ti99iuc
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Re: TI99/4A

Post by ti99iuc »

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