ENTERPRISE KLUB
2019. május 25., 1055 Budapest, Nyugati tér 9. 14-19 óráig
Részletek
Welcome, Guest. Please login or register.


Author Topic: Creating EXDOS card clone (Read 24497 times)

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Creating EXDOS card clone
« on: 2014.September.11. 13:12:39 »
Quote from: jltursan
Btw, in a spanish forum, we're trying to clone the EXDOS controller: Controladora de disco para Enterprise
It's only in spanish, sorry. Also, the forum engine is a bit retrictive and links are not shown to unregistered users :(; but I'll be happy to give you all details about the development.

Why not talk about it some months earlier? :oops:

It is looks as creating full clone of the original card. But it is can be optimized for a less components!

Firstly see the floppy part of the MICROTEAM card. It is (and all other hungarian clones) using 2 7406 instead 3 7438.
It is use 74LS245 instead 74LS126 because the 245 ICS are more common.

And the main problem with the original card: it is developed for a "Plug and Play" bus system, where the bus sockets have a extra socket address pins, and these are also used for memory and I/O address decoding. Each slot have a different address space.
But this system never released, because the Enterprise company crashed :-(
Only the one socket System Bus Bridge and the original EXDOS card used this complex address decoding method.
All other expansion and EXDOS clones used a fixed address decoding for a less components.

For a build new EXDOS clone I also suggest fixed decoding.
For a ROM I suggest a 512K Flash ROM IC, it is can be filled with lot of programs :-) and optionaly can be added 512K SRAM chips as RAM expansion, because easy to do it :-)
For 512K ROM chip + X*512K SRAM only needed ONE 74HCT138 as address decoder!
And I think another two chips enought for the I/O decoding.

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #1 on: 2014.September.11. 13:18:18 »
Another suggestion: add jumpers for the floppy connector to make selectable original Shugart or PC/AT pinout. For using original flat cable with jumperable drives, or using twisted cable with modern 3.5" drives without jumpers.

Offline jltursan

  • User
  • *
  • Posts: 69
  • Country: es
  • OS:
  • Windows NT 6.3 Windows NT 6.3
  • Browser:
  • Firefox 27.0 Firefox 27.0
    • View Profile
    • JLTurSan's MSX page - My little MSX corner
Re: Creating EXDOS card clone
« Reply #2 on: 2014.September.11. 13:22:36 »
It's a very recent project that take us all by surprise :). In fact, the man behind it is an Apple fan recently abducted by Enterprise's dark side :ds_icon_cheesygrin:

I'm not sure about their skills and if he's confident enough to change the original design; but if I have your permission, I'll translate your suggestions to the thread.

[uote]Another suggestion: add jumpers for the floppy connector to make selectable original Shugart or PC/AT pinout. For using original flat cable with jumperable drives, or using twisted cable with modern 3.5" drives without jumpers.[/quote]

I suposse you mean swapping A: & B:. I'm not sure if Enterprise uses /RDY, /DC and /DCreset signals...

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #3 on: 2014.September.11. 13:27:00 »
And as I wrote in the other topic: use WD1772. It is exist a ROM version which are set the stepping rate default to 3ms.

Anyway I see on the photos: using version 1.3. It is can be possible the modified version which are not too godd choice for 1770, because the setting which are 3ms on 1722 30ms on 1770 :oops:
The :VAR 73 command what answering? 0 or 3?
0 good for 1770 (6ms stepping rate, this is the fastest on 1770), 3 good for 1772 (3ms)
« Last Edit: 2014.September.11. 13:33:54 by Zozosoft »

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #4 on: 2014.September.11. 13:33:31 »
Quote from: jltursan
I'll translate your suggestions to the thread.
Please do it!

Quote
I suposse you mean swapping A: & B:.
Yes, the change about the drive select and motor on wires.

Quote
I'm not sure if Enterprise uses /RDY, /DC and /DCreset signals...
We are very lucky! (Thanks for Bruce and friends! :ds_icon_cheesygrin: )
EXDOS don't use RDY and as default don't use hardware disk change signals. Then any (300RPM rotation) drive can be used. Many other machine have a lot of problem about these signals, and hard to replace their drives.

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #5 on: 2014.September.11. 15:22:18 »
Quote from: Zozosoft
And as I wrote in the other topic: use WD1772. It is exist a ROM version which are set the stepping rate default to 3ms.

Anyway I see on the photos: using version 1.3. It is can be possible the modified version which are not too godd choice for 1770, because the setting which are 3ms on 1722 30ms on 1770 :oops:
The :VAR 73 command what answering? 0 or 3?
0 good for 1770 (6ms stepping rate, this is the fastest on 1770), 3 good for 1772 (3ms)
Do you noted this? :oops: Please also write to the developer.

Offline jltursan

  • User
  • *
  • Posts: 69
  • Country: es
  • OS:
  • Windows NT 6.3 Windows NT 6.3
  • Browser:
  • Firefox 27.0 Firefox 27.0
    • View Profile
    • JLTurSan's MSX page - My little MSX corner
Re: Creating EXDOS card clone
« Reply #6 on: 2014.September.11. 15:49:47 »
I missed it!. It's reported now

Online gflorez

  • EP addict
  • *
  • Posts: 2558
  • Country: es
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
Re: Creating EXDOS card clone
« Reply #7 on: 2014.September.11. 17:44:15 »
Hello Jltursan. I'm interested on that blog but it doesn't permits more members....

---------------
Hola Jltursan. Estoy interesado en ese blog, pero no permite nuevos miembros...

Online gflorez

  • EP addict
  • *
  • Posts: 2558
  • Country: es
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
Re: Creating EXDOS card clone
« Reply #8 on: 2014.September.11. 19:47:43 »
Ah vale ya entiendo, hay que mandarles un email antes...

---------------

Ah, I understand it, I must send them an email before...


To retrowiki @ retrowiki.es with a brief description of your interests.

(The spaces inside the direction seem to be important but I've send another email without them yust in case...)
« Last Edit: 2014.September.11. 19:54:39 by gflorez »

Offline jltursan

  • User
  • *
  • Posts: 69
  • Country: es
  • OS:
  • Windows NT 6.3 Windows NT 6.3
  • Browser:
  • Firefox 27.0 Firefox 27.0
    • View Profile
    • JLTurSan's MSX page - My little MSX corner
Re: Creating EXDOS card clone
« Reply #9 on: 2014.September.11. 21:57:18 »
I've also contacted the site admin telling him about you ;-)

-------------------------------------

Yo también he contactado con el administrador y le he hablado de tí ;-)

Online gflorez

  • EP addict
  • *
  • Posts: 2558
  • Country: es
  • OS:
  • Windows 7/Server 2008 R2 Windows 7/Server 2008 R2
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
Re: Creating EXDOS card clone
« Reply #10 on: 2014.September.11. 22:54:26 »
Muchas gracias Jltursan.

-----------------------

Thank you Jltursan.

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #11 on: 2014.September.12. 10:57:28 »
I read - with google translate - some discussion about 3.5" drives.

The original cards with 7438 ICs and clone cards with 7406 ICs work with any 3.5" drives (old or modern) without any problem.
A HD drive can be used with DD disks, or cover the HD sense hole on HD disks.
« Last Edit: 2014.September.13. 17:25:50 by szipucsu »

Offline jltursan

  • User
  • *
  • Posts: 69
  • Country: es
  • OS:
  • Windows NT 6.3 Windows NT 6.3
  • Browser:
  • Firefox 27.0 Firefox 27.0
    • View Profile
    • JLTurSan's MSX page - My little MSX corner
Re: Creating EXDOS card clone
« Reply #12 on: 2014.September.12. 12:16:13 »
Indeed, they work fine. Seems that 74LS38 were used instead 7438 and they're giving some problems. He replaced two of three with real 7438 and the card looked more stable, he's now waiting for some 7438 to keep testing with all three replaced. The card is in a very alpha stage tho...

I think that once the prototype works, some optimizations will be performed on it.

Online Zozosoft

  • EP addict
  • *
  • Posts: 13336
  • Country: hu
  • OS:
  • Windows XP Windows XP
  • Browser:
  • Firefox 31.0 Firefox 31.0
    • View Profile
    • http://enterprise.iko.hu/
Re: Creating EXDOS card clone
« Reply #13 on: 2014.September.12. 12:33:52 »
I think 7406 are more common, at least in Hungary :-) I can get them in many shops. But 7438 needed to be ordered from Ebay.
« Last Edit: 2014.September.13. 17:26:43 by szipucsu »

Offline jltursan

  • User
  • *
  • Posts: 69
  • Country: es
  • OS:
  • Windows NT 6.3 Windows NT 6.3
  • Browser:
  • Firefox 27.0 Firefox 27.0
    • View Profile
    • JLTurSan's MSX page - My little MSX corner
Re: Creating EXDOS card clone
« Reply #14 on: 2014.September.12. 21:17:40 »
Good news!, seems that the controller was 100% working after all. It was only a big mess with the cabling used :oops:

Now it's time to polish the design...