SCSI interface ICD Micro adaptation for Mega STe

[tOriman]

Hi,

I present a free adaptation of the ICD interface designed exclusively for the Atari Mega STe series and mounted to the inside of the computer in the place intended for such interfaces on the internal ACSI connector.

MegaSTe Internal Micro.jpg

The design has been improved over the original ICD Micro by adding a circuit parity bit generator and termination resistors on the SCSI lines. Other than that full functionality of the ICD Micro has been retained, i.e. the basic limitation of the Atari internal adapter - the size of the disk max. 1GB no longer exists and you can mount a disk of any size.

Have been carried out by colleagues μicr0Bee and Kroll from the Atari Area forum very thorough and comprehensive tests of this interface. Everything works very well with one caveat - UltraSaTan has problems with stable operation. This is dependent on the copy of the hardware. Tests shows that devices powering is also important. Partitions on SD cards can sometimes disappear, there are sometimes errors when copying large amounts of data, and the like. An older version of the US, the one from Jookie has few of these incidents, and in principle it applies to some copies of SD cards, which can lose data. The most stable behavior of the whole in the configuration: HDD SCSI (ID0), US (ID3,ID4). Tests with "good old" devices, i.e. Megafile drives and also newer ACSI2STM and also SCSI2SD passed without the slightest problems, which indirectly indicates that the strange behavior of the US is related to the UltraSaTan itself rather than with the interface. As I wrote in the introduction - this is an adaptation of the of the original ICD Micro scheme, which successfully worked in the computers of the MegaST.

All documentation (schematics, gerber files and GALs firmware) you can find on my www. ICD Micro interface supports ID0...ID3 only on bus so devices with numbers higher than 3 would be invisible.

I give everything as always - for free and invite you to use this cool "old-new" device :)

Greetings
tOri

[alexh]

Thanks for sharing.

http://atari.myftp.org/atari16bit/icdmste/icdmste.html

[Tomswork]

Does anyone know what size the 100nf and 1k smd resistors are in this build I can't read the website and the schematics don't say


Tom

[rubber_jonnie]

Does anyone know what size the 100nf and 1k smd resistors are in this build I can't read the website and the schematics don't say


Tom

At a guess, I'd say either 0402, 0603 or 0805. I presume these are on the PCB schematic files on the link alexh shared.

[DoG]

Looks like 0805. Measured pad sizes in gerbview in KiCad. Compared it against recommended solder pad dimensions for different smd sizes. 0805 seems to be the closest to it.

[Tomswork]

Excellent thank you I ordered a set of boards from jlcpcb and I think I have all the parts


Tom

[tOriman]

Hi,

All SMD parts are 0805.

Greetings
tOri

[Badwolf]

I give everything as always - for free and invite you to use this cool "old-new" device :)

Another great project. Dzieki, t0riman.

BW