Speed is of the essence

[ParanoidLittleMan]

Something like that is written at entrance of one level in best Atari ST game Dungeon Master (shame on you Atarimania voters, only 22-ond ??) .

OK, exact text is: Time is of the essence. But what is time, what is speed ? Two goes one with other, and can't be separated. Even in languages - we have term tempo - it originates from latin tempus, what means time  ?

So, things are that my two projects, about what was written here, on my WEBsite will finally be available for purchase:

CATA and ACSI-CF mass storage (hard disk compatible) interfaces (adapters) for Atari ST(E) machines. And yes, they are fastest ones for them.

 

ACSI-CF is later, and schematic, GAL logic, driver SW is published. Many people built it with success, some with no success. I got plenty of e-mails, and some vary bad ones, with suggestions about driver SW, from people who even did not take care to look how ACSI port (DMA) exactly works.

This year 2 people wrote me that made reliably working PCB for it (write is hard case), and tori from Poland is willing to spread it and help me in production.

And he redesigned it, so is with more up to date Xilinx CPLD . Other PCB, from French guy is with my original HW design (GAL + 2 74xxx chips).

As is visible, it goes on ACSI port, has power connector (needs +5V stabilized) , and is for Compact Flash cards. Actually for Sandisk Compact Flash cards.

Only with them can achieve high speed - and it is 1.9 MBytes/sec in read & write.  Why only Sandisk ? Because only it supports 8-bit DMA mode, and ACSI port is 8-bit. CF cards can work as IDE hard disks, and there are some DMA modes implemented.

It needs special driver, what is done. Under work is autoboot support for TOS - needs additional code in TOS ROM for that. It is short, about 650 bytes, so fits in all TOS versions. Of course, it is not mandatory, it can work by loading driver from floppy, or other hard disk/Flash card adapter, or even from cartridge (what is another way of autoboot).  I will make concrete TOS add-ons on demand (TOS image files, or programmed EPROMs), at start only few, like 1.04, 1.62 UK, US will be ready.

Price: will calculate it in next days, week. It will include driver SW price - because no way to use it without my special driver (well, unless someone writes self another one, for).

Tested with some 8 diverse Sandisk CF cards, with success. Range 2 - 16 GB .

 

CATA: it will be available in 2 versions:  external, for cartridge port (name is CA (cartridge) ATA - other name for IDE disks, Flash cards in IDE/ATA mode).

Internal: for ST machines, as board what goes over CPU, will have 40-pin IDE connector, where can connect IDE cable, on what can attach classic hard disk, or CF card via IDE-CF adapter (cheap, passive adapter) . Maybe should call it FATA (fast ATA) ?

It can work with classic hard disks, most of CF cards, so not only Sandisk, because works in regular, so called PIO 16 bit mode.

Max speed is over 3 Mbytes/sec in read. But it needs little + work, even in case of external version - need to cut /RW line what leeds from CPU to MMU chip, and pass that signal over adapter. Really not much work, of course needs care, schematic of computer. Not mandatory. Without it max read speed is about 1500 Kbytes/sec, and write speed about 2 Mbytes/sec. Speed depends from used card/disk and driver SW version too.

External: it works best with STE machines. Because by STs signal delays are much higher on lines going to cartridge port, it may be unreliable, especially with now very old machines, so internal is recommended.  External includes EPROMs on cartridge, where driver is placed, and it solves autoboot too. It can not work without those ROMs - high speed is achieved by special code on ROMs, and HW logic.  And one thing more: please don't ask about work together with other cartridge adapters: it will not work. Also, I don't want to spend time and money with TT and Falcon support. Those machines have mass storage in most cases, so no real need.

Internal version needs update of TOS ROMs - from same reason - driver code core must run from ROM. That could be solved with adding 2 EPROMs on board, but I don't think that it is good idea. It costs extra money, while TOS update is needed - because autoboot, and because is recommended to update STs to 1.04 .  And there is TOS 2.06 support too for ST machines on internal board.  So, users of internal can have 6 EPROM chips with updated TOS, + some other compatible TOS version, switchable (will send 27C512 chips, where 2 TOS versions fit) . Or 2 32 pin EPROMs for TOS 2.06 , or even both, I mean 6 chips for TOS 1.0x, 2 chips for 2.06 (with added FATA code).

Yeah, all this may seem pretty complicated, for some hard to follow, but I like to present it with details and proper terms. Things are not simple with Atari ST serial and mass storage, and I even did not talk here about most time consuming part: SW for it.

More details soon ....

 

 

 

 

[guus.assmann]

Hello,

Thanks for the presentation and the hard work behind it.

And of course I'm curiuos about the price.

Please keep up the good work :-)

 

BR/

Guus

[snarkdluG]

I have also started building mine. Almost finished. I have not programmed the Xilinx yet or soldered in a DB19. Got all the info from tOris site.

[t0ri]

Hello,

 

@snarkdluG - I found on exxos's site that You don't know how to solder DB19 plug to PCB. Simplest way used by me is:

 

- pull the pins out of the goldpin connector (header - see attached pic)

- solder pins first to DB19M plug

- solder complete plug to PCB in row CLOSER to xilinx like that on Peter's photo (TOP of PCB)

- cut the ends of pins and all is ready.

 

If You need parallel ACSI bus - prepare the DB19F socket in the same way as the DB19 plug and solder the bottom side of the PCB in the row closer to the edge of the board.

 

Thanks to Peter for awesome soft- and hardware. He's projects are awesome and worth of interest.

 

 

[snarkdluG]

Thanks for the tip @t0ri. Yeah, I have a DB19M now. I was thinking of other solutions since I have seen pcb cables done for the DB19 with loose pins solder to the pcb. Lotharek have such for sale. A DB19 is quite pricey.

 

But I think I will go for your solution now.  

Edited October 22, 2020 by snarkdluG

[t0ri]

Hello,

 

This solution is really simplest one ? You should remember that DMA chip is working almost on the vedge of its possibilities, therefore any connections must be short as possible. Any cable may introduce noise causing errors. I want to warn anyone who will use this interface with Atari older than STe serie because lack of DMA lines buffering. In case of errors, there is a need to pull-up data lines to +Vcc using resistor pack 1x9 soldered directly to data pins of WD1772. Atari STe and up have DMA data lines buffered.

 

Regards

tOri

[ParanoidLittleMan]

Now this is ready for sale/shipping to people.

Details here: http://atari.8bitchip.info/acsicfafs.html

Will be added more in next days ..

 

[didier60]

Bonjour

je viens de voir votre vidéo super matérielle, vous ferai des envois pour la France?

 

[ParanoidLittleMan]

Added another YT video, showing driver with Virtual Floppy boot process, changing active floppy image in TOS 2.06 ...  :

 

[ParanoidLittleMan]

There are still 3 adapters available from first batch. And hopefully now shipping goes faster than in 2nd, 3rd wave months.

I made more SW support for it, so autoboot code for all TOS versions is ready, and there are improved TOS versions (1.04i, 1.62i) with ACSI-CF integrated driver + integrated partitioner (max 30 partitions of max 1 GB size) .

http://atari.8bitchip.info/acsicfafs.html

http://atari.8bitchip.info/tosimprgu.html