exxos IDE interface (untested)

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exxos
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exxos IDE interface (untested)

Post by exxos » Sun Nov 19, 2017 9:54 pm

I keep getting asked about adding IDE to my boosters.. well.. This is one circuit I designed months ago.. I just don't have time to build it and test it. If someone wants to build and test it for me.. please do so.. Its the only way IDE will be added as I just don't have the 500 hour days to do everything people want.

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I can't remember much of how I designed it. But I was talking to Esa Sorsa months ago. I tried to emulate better IDE timings as every other IDE solution either doesn't work at all, or has issues with various CF card brands/types. I tried to build in fixes for that and also added in IORDY support (assuming the CF supports it).


Probably this was the initial timings chart I did for it...
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IDE_PIO_timing_AtariTim.png
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4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: exxos IDE interface (untested)

Post by Smonson » Mon Nov 20, 2017 6:15 am

Is that all you need to do to communicate with an IDE drive? I thought it would be much more complicated than that.

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Re: exxos IDE interface (untested)

Post by exxos » Mon Nov 20, 2017 8:32 am

Smonson wrote:
Mon Nov 20, 2017 6:15 am
Is that all you need to do to communicate with an IDE drive? I thought it would be much more complicated than that.
Other circuits use a lot less parts, which is probably why they don't work so good ;)
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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Re: exxos IDE interface (untested)

Post by exxos » Thu Nov 30, 2017 3:06 pm

TerribleFire has ported my IDE design over for testing. Awesome stuff!

I particularly enjoyed all the mentions of me ;)


4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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Re: exxos IDE interface (untested)

Post by Petari » Wed Dec 06, 2017 9:23 am

As person who designed, and used one of the first IDE adapters for Atari ST, back in 1992, I need to say some things here.
It was not even called usually IDE in those times - it was AT bus adapter. And whole design is really simple - may see schematic on atari.8bitchip.info
.
Basically, adapter acts in some way as port - it has it's address range, and when it is addressed by CPU it is connected to bus and can read or write.
So, minimal design needs address decoder - best was to do it with GAL, but I seen solution with 74xxx logic too. Of course need to generate proper DTACK, and in that time IORDY was a must because slow hard disks. What is most important to say is: there were no timing problems with those old hard disks, not for me - with Atari ST and more complicated design with Sinclair Spectrum. Why - simply just because disks were made for AT bus - so for microcomputer bus. Those disks knew only CHS addressing, there was no DMA mode, there were no faster PIO modes.

Problems started later, with introducing of new PIO modes, what required new timing scheme, and that just not matches some micro computer bus timing. And much bigger problems with CF cards, especially fast ones.

So, in case of Atari ST, Falcon there is timing problem, mostly write is affected, + signal interfacing problem.
To add that I made some tests recently with 16 GB Sandisk Extreme CF card, what is some medium fast one by today standards, on 4 little older PC motherboards, which have PATA connectors. Only on 2 of 4 it worked reliable. And those ATA ports are way faster than some Atari - can Ultra DMA 5 (or what is the fastest one) . PIO modes are much faster too. To add that all boards work flawless with classic hard disks - tested with range 20-120 GB .
Indeed some signal interfacing problem. Changing voltage for card on IDE-CF adapter changed nothing.

I would say that even physical layout of lines is very important - based on my experiences with prototype boards.

Unfortunately, I'm not able to deal with HW as earlier from diverse reasons. Have some unfinished projects. And SW is what actually needs most time.
CF cards may be still interesting - even if it is now hard to see in shops, and are more expensive than SD.
Solution could be some IDE-SD adapter - they are often slow for some PC, but fine for Ataris. Price is low, so it pays. And it seems that interfacing is much better - I had no problems on Falcon, on 4 mentioned PCs with cheap (and for PC slow) IDE-SD adapter.
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Re: exxos IDE interface (untested)

Post by exxos » Wed Dec 06, 2017 12:53 pm

I had some issues on Falcon with unstable CF cards. Problem seem to get worse with same card, maybe failing PSU, but even so, I swapped CF for IDE to SD adapter and works well. Such adapters are buffered by the control logic, also timings likely less important.

Ultimately, I want to get IDE working, and move to a IDE to USB bridge (similar to what TF does). Then just avoid all IDE/CF stuff and use USB sticks.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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